FORM 10-Q

UNITED STATES
SECURITIES AND EXCHANGE COMMISSION

       (Mark One)

For the transition period from          to

Commission file number 000-30171

SANGAMO BIOSCIENCES, INC.

501 Canal Blvd, Suite A100
Richmond, California 94804
(Address of principal executive offices)

(510) 970-6000
(Registrant’s telephone number, including area code)

     Indicate by check mark whether the registrant (1) has filed all reports required to be filed by section 13 or 15(d) of the Securities Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days:

Indicate by check mark whether the registrant is an accelerated filer (as defined in Rule 12b-2 of the Exchange Act).

     As of May 5, 2005, 25,379,967 shares of the issuer’s common stock, par value $0.01 per share, were outstanding.

INDEX

SANGAMO BIOSCIENCES, INC.

Some statements contained in this report are forward-looking with respect to our operations, economic performance and financial condition. Statements that are forward-looking in nature should be read with caution because they involve risks and uncertainties, which are included, for example, in specific and general discussions about:

Various terms and expressions similar to them are intended to identify these cautionary statements. These terms include: “anticipates,” “believes,” “continues,” “could,” “estimates,” “expects,” “intends,” “may,” “plans,” “seeks,” “should” and “will.” Actual results may differ materially from those expressed or implied in those statements. Factors that could cause these differences include, but are not limited to, those discussed under “Risks Related to Our Business” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations.” Sangamo undertakes no obligation to publicly release any revisions to forward-looking statements to reflect events or circumstances arising after the date of this report. Readers are cautioned not to place undue reliance on the forward-looking statements, which speak only as of the date of this Quarterly Report.

2

PART 1. FINANCIAL INFORMATION

ITEM 1. FINANCIAL STATEMENTS

SANGAMO BIOSCIENCES, INC.

See accompanying notes.

3

SANGAMO BIOSCIENCES, INC.

See accompanying notes.

4

SANGAMO BIOSCIENCES, INC.

See accompanying notes.

5

SANGAMO BIOSCIENCES, INC.

NOTE 1-BASIS OF PRESENTATION AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

BASIS OF PRESENTATION

     The accompanying unaudited condensed consolidated financial statements of Sangamo Biosciences, Inc. (“Sangamo” or the “Company”) have been prepared in accordance with generally accepted accounting principles for interim financial information and pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Accordingly, they do not include all of the information and footnotes required by generally accepted accounting principles for complete financial statements. In the opinion of management, all adjustments (consisting of normal recurring adjustments) considered necessary for a fair presentation have been included. The condensed consolidated financial statements include the accounts of Sangamo and its wholly-owned subsidiary, Gendaq Limited, after elimination of all material intercompany balances and transactions. Operating results for the three-months ended March 31, 2005 are not necessarily indicative of the results that may be expected for the year ending December 31, 2005. These financial statements should be read in conjunction with the financial statements and footnotes thereto for the year ended December 31, 2004, included in Sangamo’s Form 10-K as filed with the SEC.

USE OF ESTIMATES

     The preparation of financial statements in conformity with generally accepted accounting principles requires management to make estimates and assumptions that affect the amounts reported in the financial statements and the accompanying notes. Actual results could differ from those estimates.

FOREIGN CURRENCY TRANSLATION

     The Company records foreign currency transactions at the exchange rate prevailing at the date of the transaction. Monetary assets and liabilities denominated in foreign currency are translated into U.S. dollars at the exchange rates in effect at the balance sheet date. All currency translation adjustments arising from foreign currency transactions are recorded through profit and loss.

REVENUE RECOGNITION

     In accordance with Staff Accounting Bulletin No. 104, “Revenue Recognition,” revenue from research activities made under strategic partnering agreements is recognized as the services are provided when there is persuasive evidence that an arrangement exists, delivery has occurred, the price is fixed or determinable, and collectibility is reasonably assured. Amounts received under such agreements are deferred until the above criteria are met and the research services are performed. Sangamo’s federal government research grants are typically multi-year agreements and provide for the reimbursement of qualified expenses for research and development as defined under the terms of the grant agreement. Revenue under grant agreements is recognized when the related research expenses are incurred. Grant reimbursements are typically received on a quarterly basis and are subject to the issuing agency’s right of audit.

     Sangamo recognizes revenue from its Universal GeneTools® agreements when ZFP TFs are delivered to the Universal GeneTools® collaborators, persuasive evidence of an agreement exists, there are no unfulfilled obligations, the price is fixed and determinable, and collectibility is reasonably assured. Generally, Sangamo receives partial payments from these collaborations prior to the delivery of ZFP TFs and the recognition of these revenues is deferred until the ZFP TFs are delivered, the risk of ownership has passed to the collaborator and all performance obligations have been satisfied. Upfront or signature payments received upon the signing of a Universal GeneTools® agreement are generally recognized ratably over the applicable period of the agreement or as ZFP TFs are delivered.

     Milestone payments under research, partnering, or licensing agreements are recognized as revenue upon the achievement of mutually agreed upon milestones, provided that (i) the milestone event is substantive and its achievement is not reasonably assured at the inception of the agreement, and (ii) there are no further significant performance obligations associated with the milestone payment.

6

     In accordance with Emerging Issues Task Force Issue No. 00-21, “Revenue Arrangements with Multiple Deliverables,” revenue arrangements entered into after June 15, 2003, that include multiple deliverables, are divided into separate units of accounting if the deliverables meet certain criteria, including whether the fair value of the delivered items can be determined and whether there is evidence of fair value of the undelivered items. In addition, the consideration is allocated among the separate units of accounting based on their fair values, and the applicable revenue recognition criterion is considered separately for each of the separate units of accounting.

RESEARCH AND DEVELOPMENT EXPENSES

     Research and development expenses consist of costs incurred for Company-sponsored as well as collaborative research and development activities. These costs include direct and research-related overhead expenses, which include salaries and other personnel-related expenses, facility costs, supplies and depreciation of facilities and laboratory equipment, as well as the cost of funding research at universities and other research institutions, and are expensed as incurred. Costs to acquire technologies that are utilized in research and development and that have no alternative future use are expensed as incurred.

STOCK-BASED COMPENSATION

     Sangamo accounts for employee and director stock options using the intrinsic value method in accordance with Accounting Principles Board Opinion No. 25, “Accounting for Stock Issued to Employees” (“APB 25”) and has adopted the disclosure-only alternative of FAS No. 123, “Accounting for Stock-Based Compensation.” Stock options granted to non-employees, including Scientific Advisory Board Members, are accounted for in accordance with Emerging Issues Task Force Issue No. 96-18, “Accounting for Equity Instruments That Are Issued to Other Than Employees for Acquiring, or in Conjunction with Selling, Goods or Services,” which requires the value of such options to be measured and compensation expenses to be recorded as they vest over a performance period. The fair value of such options is determined using the Black-Scholes model. The following table illustrates, pursuant to FAS No. 123, as amended by FAS No. 148, “Accounting for Stock-Based Compensation—Transition and Disclosure,” the effect on net loss and related net loss per share had compensation cost for stock-based employee compensation plans been determined based upon the fair value method prescribed under FAS No. 123:

     The above pro forma effects may not be representative of that to be expected in future periods, due to subsequent events including additional grants and related vesting. The fair values for all options granted in the three-month periods ended March 31, 2005 and 2004 were estimated at the date of grant using the Black-Scholes method with the following weighted-average assumptions:

7

NOTE 2-BASIC AND DILUTED NET LOSS PER SHARE

     Basic and diluted net loss per share have been computed using the weighted-average number of shares of common stock outstanding during the period. Weighted-average shares outstanding used to calculate the reported net loss per common share were equal to shares used to compute basic and diluted net loss per common share.

NOTE 3-COMPREHENSIVE LOSS

     Comprehensive loss is comprised of net loss and other comprehensive income (loss). Other comprehensive loss includes certain changes in stockholders’ equity that are excluded from net loss, which includes unrealized gains and losses on our available-for-sale securities and foreign currency translation adjustments. Comprehensive loss and its components are as follows (in thousands):

NOTE 4-MAJOR CUSTOMERS, PARTNERSHIPS AND STRATEGIC ALLIANCES

Strategic Partnership with Edwards Lifesciences Corporation

     In January 2000, we announced a therapeutic product development collaboration with Edwards Lifesciences Corporation. Under the agreement, we have licensed to Edwards, on a worldwide, exclusive basis, ZFP Therapeutics for use in the activation of VEGFs and VEGF receptors in ischemic cardiovascular and vascular diseases. Edwards purchased a $5.0 million note that converted, together with accrued interest, into 333,333 shares of common stock at the time of our initial public offering (IPO) at the IPO price. In March 2000, Edwards purchased a $7.5 million convertible note in exchange for a right of first refusal for three years to negotiate a license for additional ZFP Therapeutics in cardiovascular and peripheral vascular diseases. That right of first refusal was not exercised and terminated in March 2003. Together with accrued interest, this note converted into common stock at the time of our initial public offering at the IPO price. Through 2001, we received $2 million in research funding from Edwards and a $1.4 million milestone payment for delivery of a lead ZFP Therapeutic product candidate. In November 2002, Edwards signed an amendment to the original agreement and agreed to provide up to $3.5 million in research and development funding, including $2.95 million for research and development activities performed in 2002 and 2003. The filing of the IND for PAD in 2004, and the achievement of other research-related milestones in 2003, triggered a total of $1.0 million in milestone payments from Edwards Lifesciences in the first quarter of 2004. Revenues attributable to milestone achievement and collaborative research and development performed under the Edwards agreements were approximately $608,000 for the three-month period ended March 31, 2004, representing 75% of total revenues earned by Sangamo for that period. There were no revenues in connection with the Edwards agreements during the three-month period ended March 31, 2005. There were no related costs or expenses incurred for services performed under the Edwards agreements for the three-month periods ended March 31, 2005 or 2004. We have no future commitments related to these agreements.

     Our License Agreement with Edwards Lifesciences provides Edwards with exclusive rights “for the activation of VEGF and VEGF receptors for the treatment and prevention of ischemic cardiovascular and vascular disease in humans.” We have retained all rights to use our technology for all therapeutic applications of VEGF activation outside of ischemic cardiovascular and vascular diseases, including use in wound healing and neurological disorders. Edwards has stated that their rights may include diabetic neuropathy. We

8

believe diabetic neuropathy is a neurological disease and not an ischemic vascular disease and therefore is outside the scope of the Edwards License. The Company and Edwards are in discussions regarding this issue.

     In the future, Sangamo may receive milestone payments and royalties under this agreement. We have received $2.5 million in milestone payments to date and we could receive $27.0 million in additional milestone payments under the agreement if all future milestones are met for the first product developed under the agreement. Any subsequent products developed under the agreement may generate up to $15.0 million in milestone payments each. We would also receive royalties on any sales of products generated under the agreement and these royalty obligations would continue until the expiration of the last-to-expire patent covering products developed under the agreement on a country-by-country basis. Based on currently issued patents, these royalty obligations would last through January 12, 2019. The development of any products is subject to numerous risks and no assurance can be given that any products will successfully be developed under this agreement. See “Risks Related to our Business — Our gene regulation technology is relatively new, and if we are unable to use this technology in all our intended applications, it would limit our revenue opportunities.”

     Under the Sangamo-Edwards agreement, we were responsible for advancing product candidates into preclinical animal testing. Edwards had responsibility for preclinical development, regulatory affairs, clinical development, and the sales and marketing of ZFP Therapeutic products developed under the agreement. Sangamo may receive milestone payments in connection with the development and commercialization of the first product under this agreement and may also receive royalties on product sales. As part of the November 2002 amendment to our original agreement, Edwards Lifesciences also entered into a joint collaboration with us to evaluate ZFP TFs for the regulation of a second therapeutic gene target, phospholamban (PLN), for the treatment of congestive heart failure. Under the amended agreement, Sangamo granted Edwards a right of first refusal to Sangamo’s ZFP TFs for the regulation of PLN. This right of first refusal terminated on June 30, 2004. On August 14, 2003 Edwards and Sangamo entered into a Third Amendment to the original license agreement. Under this amendment, Sangamo received payment for research and development milestones associated with the VEGF and PLN programs.

     There is no assurance that the companies will achieve the development and commercialization milestones anticipated in these agreements. Edwards has the right to terminate the agreement at any time upon 90 days written notice. In the event of termination, we retain all payments previously received as well as the right to develop and commercialize all related products.

Enabling Technology Agreements for Pharmaceutical Protein Production

     Protein pharmaceuticals manufactured with genetically modified cells accounted for more than $13.3 billion in annual worldwide sales in 2001. Of this total, monoclonal antibodies accounted for approximately $2.6 billion. Industry experts believe that the introduction of new protein pharmaceuticals may lead to a significant shortfall in production capacity over the next several years.

     In January 2005, we announced a research collaboration agreement with Pfizer Inc to develop enhanced cell lines for protein pharmaceutical production. Under the terms of the agreement, Pfizer is funding research at Sangamo and Sangamo will provide our proprietary ZFP technology for Pfizer to assess its feasibility for use in mammalian cell-based protein production. We will generate novel cell lines and vector systems for enhanced protein production as well as novel technology for rapid creation of new production cell lines. During the three-month period ended March 31, 2005, we received $500,000 in research-related funding under the agreement with Pfizer. Revenues attributable to collaborative research and development performed under the Pfizer agreement were $125,000 for the three-month period ended March 31, 2005, representing 49% of total revenues earned by Sangamo during that period. As of March 31, 2005 accounts receivable from Pfizer represented 66% of our total accounts receivable balance.

Enabling Technology Agreements for Regenerative Medicine

     In September 2004, Sangamo announced that it had entered into an agreement with LifeScan, Inc., a Johnson & Johnson company. The agreement provides LifeScan with Sangamo’s ZFP TFs for use in a program to develop therapeutic cell lines as a potential treatment for diabetes. In December 2004, this agreement was expanded to include additional targets important in diabetes. The agreements represented Sangamo’s first collaboration in the field of regenerative medicine. During the three-month period ended March 31, 2005, revenues attributable to collaborative research and development performed under the LifeScan agreement were approximately $55,000, representing 21% of total revenues earned by Sangamo during that period.

9

ITEM 2. MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS

     The discussion in “Management’s Discussion and Analysis of Financial Condition and Results of Operations” contains trend analysis, estimates and other forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements include, without limitation, statements containing the words “believes,” “anticipates,” “expects,” “continue,” and other words of similar import or the negative of those terms or expressions. Such forward-looking statements are subject to known and unknown risks, uncertainties, estimates and other factors that may cause the actual results, performance or achievements of the Company, or industry results, to be materially different from any future results, performance or achievements expressed or implied by such forward-looking statements. Actual results could differ materially from those set forth in such forward-looking statements as a result of, but not limited to, the “Risks Related to Our Business” described below. You should read the following discussion and analysis along with the “Selected Financial Data” and the financial statements and notes attached to those statements included elsewhere in this report.

Overview

     We were incorporated in June 1995. From our inception through March 31, 2005, our activities related primarily to establishing and operating a biotechnology research and development organization and developing relationships with our corporate collaborators. Our scientific and business development endeavors currently focus on the engineering of novel zinc finger DNA binding proteins (ZFPs) for the regulation and modification of genes. We have incurred net losses since inception and expect to incur losses in the future as we continue our research and development activities. To date, we have funded our operations primarily through the issuance of equity securities, borrowings, payments from federal government research grants and from corporate collaborators and strategic partners. As of March 31, 2005, we had an accumulated deficit of $100.7 million.

     Our revenues have consisted primarily of revenues from our corporate partners for ZFP TFs, contractual payments from strategic partners for research programs and research milestones, and Federal government research grant funding. We expect revenues will continue to fluctuate from period to period and there can be no assurance that new collaborations or partner fundings will continue beyond their initial terms.

     During 2004, we began placing more emphasis on higher-value therapeutic product development and related strategic partnerships and less emphasis on our Universal GeneTools® collaborations. We believe this shift in emphasis has the potential to increase the return on investment to our stockholders by allocating capital resources to higher value, therapeutic product development activities. At the same time, it may reduce our revenues over the next several years and it increases our financial risk by increasing expenses associated with product development. During the first quarter of 2005, we filed an Investigational New Drug (IND) application with the U.S. Food and Drug Administration (FDA) and have now initiated our own Phase I clinical trial of a ZFP Therapeutic in patients with diabetic neuropathy. Development of novel therapeutic products is costly and is subject to a lengthy and uncertain regulatory process by the FDA. Our future products are gene-based therapeutics. Adverse events in both our own clinical program and other programs in gene therapy may have a negative impact on regulatory approval, the willingness of potential commercial partners to enter into agreements and the perception of the public.

     Research and development expenses consist primarily of salaries and related personnel expenses, laboratory supplies, allocated facilities costs, subcontracted research expenses, and expenses for patent prosecution, trademark registration and technology licenses. Research and development costs incurred in connection with collaborator-funded activities are expensed as incurred. We believe that continued investment in research and development is critical to attaining our strategic objectives. We expect these expenses will increase significantly as we focus increasingly on development of ZFP Therapeutics. The Company is also developing zinc finger nucleases (ZFNs) for therapeutic gene correction and therapeutic gene modification as a treatment and possible cure for certain monogenic and infectious diseases. Additionally, in order to develop ZFP TFs as commercially relevant therapeutics, we expect to expend additional resources for expertise in the manufacturing, regulatory affairs and clinical research aspects of biotherapeutic development.

     General and administrative expenses consist primarily of salaries and related personnel expenses for executive, finance and administrative personnel, professional fees, allocated facilities costs and other general corporate expenses. As we pursue commercial development of our therapeutic leads we expect the business aspects of the Company to become more complex. We may be required in the future to add personnel and incur additional costs related to the maturity of our business.

10

Enabling Technology Programs

     We began marketing our Enabling Technologies to the pharmaceutical and biotechnology industry in 1998. Our Enabling Technology Agreements are based upon the delivery of an engineered ZFP TF that is capable of regulating the expression of a gene for which it is specifically designed and targeted. These agreements typically involve non-exclusive rights to use one or more ZFP TFs for internal research purposes or limited commercial applications.

     As the emphasis of our pharmaceutical research and development has shifted away from target validation to the downstream bottlenecks of the drug discovery process, we have refocused our Enabling Technology products and services on two principal areas: supplying our partners with our ZFP technology to enhance the production of pharmaceutical proteins, and providing ZFP TFs or ZFP-engineered cells which over-express a gene of interest for use in development of products for regenerative medicine or in the generation of cell lines for high-throughput compound screening. In the latter case, typically, pharmaceutical company researchers will use a cDNA encoding the drug target of interest to create these cell-based drug screens. However, if a third party holds a patent covering that cDNA, the pharmaceutical company might be prevented from using it for this purpose. Use of the ZFP-engineered cell-based system allows our partners to screen against drug targets whose gene and/or cDNA sequence is covered by competitor intellectual property, without infringing that intellectual property.

Plant Agriculture

     Sangamo scientists and collaborators have shown that ZFP TFs can be used to regulate the expression of endogenous genes in plants with similar efficacy as has been shown in various mammalian cells and organisms. The ability to identify and subsequently regulate gene expression with engineered ZFP TFs may lead to the creation of new plants that increase crop yields; lower production costs; are more resistant to herbicides, pesticides, and plant pathogens; and permit the development of branded agricultural products with unique nutritional and processing characteristics. In addition, ZFNs can be used to facilitate the efficient and reproducible production of transgenic plants. To commercialize ZFP TFs and ZFNs in agricultural biotechnology, we intend to seek strategic relationships with corporate partners having capabilities in the research, development, and commercialization of agricultural products.

11

Critical Accounting Estimates

     The preparation of financial statements in conformity with accounting principles generally accepted in the United States requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Sangamo believes the following critical accounting policies have significant effect in the preparation of our consolidated financial statements.

Revenue Recognition

     In accordance with Staff Accounting Bulletin No. 104, “Revenue Recognition,” revenue from research activities made under strategic partnering agreements is recognized as the services are provided when there is persuasive evidence that an arrangement exists, delivery has occurred, the price is fixed or determinable, and collectibility is reasonably assured. Amounts received under such agreements are deferred until the above criteria are met and the research services are performed. Sangamo’s federal government research grants are typically multi-year agreements and provide for the reimbursement of qualified expenses for research and development as defined under the terms of the grant agreement. Revenue under grant agreements is recognized when the related research expenses are incurred. Grant reimbursements are typically received on a quarterly basis and are subject to the issuing agency’s right of audit.

     Sangamo recognizes revenue from its Universal GeneTools® agreements when ZFP TFs are delivered to the Universal GeneTools® collaborators, persuasive evidence of an agreement exists, there are no unfulfilled obligations, the price is fixed and determinable, and collectibility is reasonably assured. Generally, Sangamo receives partial payments from these collaborations prior to the delivery of ZFP TFs and the recognition of these revenues is deferred until the ZFP TFs are delivered, the risk of ownership has passed to the collaborator and all performance obligations have been satisfied. Upfront or signature payments received upon the signing of a Universal GeneTools® agreement are generally recognized ratably over the applicable period of the agreement or as ZFP TFs are delivered.

     Milestone payments under research, partnering, or licensing agreements are recognized as revenue upon the achievement of mutually agreed upon milestones, provided that (i) the milestone event is substantive and its achievement is not reasonably assured at the inception of the agreement, and (ii) there are no further significant performance obligations associated with the milestone payment.

     In accordance with Emerging Issues Task Force Issue No. 00-21, “Revenue Arrangements with Multiple Deliverables,” revenue arrangements entered into after June 15, 2003, that include multiple deliverables, are divided into separate units of accounting if the deliverables meet certain criteria, including whether the fair value of the delivered items can be determined and whether there is evidence of fair value of the undelivered items. In addition, the consideration is allocated among the separate units of accounting based on their fair values, and the applicable revenue recognition criterion is considered separately for each of the separate units of accounting.

Stock-Based Compensation

     Sangamo accounts for employee and director stock options using the intrinsic value method in accordance with Accounting Principles Board Opinion No. 25, “Accounting for Stock Issued to Employees” (“APB 25”) and has adopted the disclosure-only alternative of Financial Accounting Standards Board Statement No. 123, “Accounting for Stock-Based Compensation” (“FAS 123”). Stock options granted to non-employees, including Scientific Advisory Board Members, are accounted for in accordance with Emerging Issues Task Force Issue No. 96-18, “Accounting for Equity Instruments That Are Issued to Other Than Employees for Acquiring, or in Conjunction with Selling, Goods or Services,” which requires the value of such options to be measured and compensation expense to be recorded as they vest over a performance period. The fair value of such options is determined using the Black-Scholes model. Pursuant to FAS 123, as amended by FAS 148, “Accounting for Stock-Based Compensation — Transition and Disclosure,” the effect on net loss and related net loss per share has been calculated, had compensation cost for stock-based compensation plans been determined based upon the fair value method prescribed under FAS 123 (See Note 1 — Organization and Summary of Significant Accounting Policies).

12

RESULTS OF OPERATIONS

Three months ended March 31, 2005 and 2004

Revenues

     We are increasing the emphasis of our research and development activities on ZFP Therapeutics and are moving away from our historic emphasis on Enabling Technology agreements. Over the next several years, this change in resource allocation will reduce our revenues.

     Total revenues decreased to $256,000 for the three months ended March 31, 2005 from $811,000 in the corresponding period in 2004. The decrease for the three months ended March 31, 2005 was principally due to a decrease of $608,000 in revenue from Edwards Lifesciences. The Company received a $600,000 milestone payment in the quarter ended March 31, 2004. We anticipate continued revenues from collaboration agreements through the end of 2005, and we have applied for, and plan to continue to apply for, federal government research grants in the future to support the development of applications of our technology platform. Although we have negotiated collaboration agreements and received federal government research grants in the past, we cannot assure you that these efforts will be successful in the future.

Operating Expenses

Research and development

     Research and development expenses have consisted primarily of salaries and related personnel expenses, laboratory supplies, allocated facilities costs, subcontracted research expenses, and expenses for patent prosecution, trademark registration and technology licenses. We expect to continue to devote substantial resources to research and development in the future and expect research and development expenses to increase in the next several years if we are successful in advancing our ZFP Therapeutic product candidates into clinical trials. To the extent we collaborate with others with respect to clinical trials, increases in research and development expenses may be reduced or avoided.

     Research and development expenses for the first quarter of 2005 decreased to $2.6 million compared to $2.8 million for the first quarter of 2004. The decrease in research and development expenses for the three months ended March 31, 2005 was primarily attributable to licensing expenses of approximately $234,000 in connection with the acquisition of certain assets and intellectual property rights from Stell, Inc. in the first quarter of 2004. Additionally, expenses related to patent prosecution and trademark licenses decreased by approximately $130,000 during the first quarter of 2005. This was partially offset by higher laboratory supplies usage of approximately $170,000 during the first quarter of 2005.

13

General and administrative

     General and administrative expenses consist primarily of salaries and related personnel expenses for executive, finance and administrative personnel, professional fees, allocated facilities costs and other general corporate expenses. As we pursue commercial development of our therapeutic leads, we expect the business aspects of the Company to become more complex. We may be required in the future to add personnel and incur additional costs related to the maturity of our business.

     General and administrative expenses were $1.1 million in the three months ended March 31, 2005, as compared to $997,000 during the corresponding period in 2004. This increase is primarily related to higher expenses associated with professional services in connection with compliance with Section 404 of the Sarbanes-Oxley Act of 2002.

Stock-based compensation

     Sangamo accounts for employee and director stock options using the intrinsic value method in accordance with Accounting Principles Board Opinion No. 25, “Accounting for Stock Issued to Employees” (“APB 25”) and has adopted the disclosure-only alternative of Financial Accounting Standards Board Statement No. 123, “Accounting for Stock-Based Compensation” (“FAS 123”). Stock options granted to non-employees, including Scientific Advisory Board Members, are accounted for in accordance with Emerging Issues Task Force Issue No. 96-18, “Accounting for Equity Instruments That Are Issued to Other Than Employees for Acquiring, or in Conjunction with Selling, Goods or Services,” which requires the value of such options to be measured and compensation expense to be recorded as they vest over a performance period. The fair value of such options is determined using the Black-Scholes model.

     Stock-based compensation expense for the quarter-ended March 31, 2005 was $101,000 compared to $182,000 for the comparable quarter in 2004. The decrease was primarily attributable to lower non-employee stock-based compensation expense. This was partially offset by higher amortization expense related to deferred compensation for stock options issued prior to the Company’s initial public offering in 2000.

Interest income, net

     Interest and other income, net, decreased to $27,000 for the three months ended March 31, 2005 from $237,000 in the corresponding period in 2004. The decrease was primarily related to a foreign currency translation loss of approximately $85,000 during the quarter-ended March 31, 2005 versus a foreign currency translation gain of approximately $82,000 during the first quarter of 2004. Additionally, an other than temporary loss on investments of approximately $68,000 was recorded in the first quarter of 2005.

Liquidity and Capital Resources

     Since inception, we have financed our operations primarily through the sale of equity securities, payments from corporate collaborators, federal government research grants and financing activities such as a bank line of credit. As of March 31, 2005, we had cash, cash equivalents, investments and interest receivable totaling $30.0 million.

     Net cash used for operating activities was $3.4 million for the three months ended March 31, 2005. Net cash used consisted primarily of the net loss for the three-month period of $3.6 million and a net change of $188,000 in operating assets and liabilities. This was partially offset by amortization of premium / discount on investment of $114,000, other stock-based compensation charges of $101,000, depreciation of $78,000 and realized losses on investments of $68,000. For the three months ended March 31, 2004, net cash used for operating activities was $2.1 million. Net cash used consisted primarily of the net loss of $2.9 million. This was partially offset by amortization of premium / discount on investment of $299,000, the issuance of common stock in connection with a license agreement of $234,000, depreciation of $196,000 and other stock-based compensation charges of $181,000.

14

     Net cash provided by investing activities was $2.3 million for the three months ended March 31, 2005 and was primarily comprised of proceeds associated with maturities of investments of $8.5 million partially offset by cash used to purchase investments of $6.1 million. For the three months ended March 31, 2004, net cash provided by investing activities was $1.7 and was primarily comprised of proceeds associated with maturities of investments of $6.8 million partially offset by cash used to purchase investments of $5.1 million.

     Net cash provided by financing activities for the three-month periods ended March 31, 2005 and 2004 was $71,000 and $167,000, respectively. Proceeds from both years were solely related to the issuance of common stock.

     While we expect our rate of cash usage to increase in the future, in particular, in support of our product development endeavors, we believe that the available cash resources, funds received from corporate collaborators, strategic partners and federal government research grants will be sufficient to finance our operations at least through 2006.

15

RISKS FACTORS

RISKS RELATED TO OUR BUSINESS

We have increased the focus of our research and development programs on human therapeutics, which may increase operating expenditures and the uncertainty of our business. We are increasing the emphasis and focus of our research and development activities on ZFP Therapeutics and have fewer resources invested in our Enabling Technology programs. In the short term, this change in resource allocation may reduce our revenues and increase operating expenditures due to larger financial outlays to fund preclinical studies, manufacturing, and clinical research. The transition will also increase the visibility of our lead therapeutic programs and the potential impact on the stock price of news releases relating to these programs.

We are conducting proprietary research to discover ZFP Therapeutic product candidates. These programs increase our financial risk of product failure, may significantly increase our research expenditures, and may involve conflicts with our collaborators and strategic partners. Our proprietary research programs consist of research which is funded solely by the Company and where the Company retains exclusive rights to therapeutic products generated by the research. This is in contrast to certain of our research programs that may be funded by corporate partners and in which we may share rights to any resulting products. We have conducted proprietary research since inception, however, in the past year, our strategy has shifted toward placing greater emphasis on proprietary research and therapeutic development and we expect this trend will continue in 2005 as we initiate our first human clinical trial. Conducting proprietary research programs may not generate corresponding revenue and may create conflicts with our collaborators or strategic partners. The implementation of this strategy will involve substantially greater business risks, the expenditure of significantly greater funds than our historic research activities and will require substantial commitments of time from our management and staff.

In addition, disagreements with our collaborators or strategic partners could develop over rights to our intellectual property with respect to our proprietary research activities. Any conflict with our collaborators or strategic partners could reduce our ability to enter into future collaboration or strategic partnering agreements and negatively impact our relationship with existing collaborators and strategic partners, which could reduce our revenue and delay or terminate our product development.

Our partner, Edwards Lifesciences, has initiated a Phase I clinical testing in our lead ZFP Therapeutic program, and ZFP Therapeutics have never before been tested in humans. If our lead ZFP Therapeutic fails its initial safety study, it could reduce our ability to attract new investors and corporate partners. Edwards Lifesciences filed an investigational new drug (IND) application with the U.S. Food and Drug Administration (FDA) on February 10, 2004 and initiated a Phase I clinical trial in humans in August, 2004. The Phase I study of our lead therapeutic will be a highly visible test of the Company’s ZFP Therapeutic approach. Since we have increased our focus on ZFP Therapeutic research and development, investors will increasingly assess the value of the Company’s technology based on the continued progress of ZFP Therapeutic products into and through clinical trials. If the initial safety study of our lead therapeutic was halted due to safety concerns, this would negatively affect the value of the Company’s stock.

Our collaborators may control aspects of our clinical trials, which could result in delays and other obstacles in the commercialization of our proposed products. For some programs we are dependent on third party collaborators to design and conduct our clinical trials. As a result, we may not be able to conduct these programs in the manner or on the time schedule we currently contemplate. In addition, if any of these collaborative partners withdraw support for our programs or proposed products or otherwise impair their development, our business could be negatively affected.

We have limited experience in conducting clinical trials, and we may encounter unanticipated toxicity or adverse events or fail to demonstrate the efficacy or safety that cause us to delay, suspend or terminate the development of our ZFP Therapeutics. Our ZFP Therapeutics may fail to show the desired safety and efficacy in initial clinical trials. Even if we successfully complete Phase I trials, the FDA will require additional Phase II and Phase III clinical testing which involves significantly greater resources, commitments and expertise that may require us to enter into a collaborative relationship with a pharmaceutical company that would assume responsibility for late-stage development and commercialization.

Our potential therapeutic products are subject to a lengthy and uncertain regulatory process, and if these potential products are not approved, we will not be able to commercialize those products. The FDA must approve any human therapeutic products before they can be marketed in the United States. The process for receiving regulatory approval is long and uncertain, and a potential product may not withstand the rigors of testing under the regulatory approval processes.

Before commencing clinical trials in humans, we or our commercial partner must submit an Investigational New Drug (IND) application to the FDA. The FDA has 30 days to comment on the IND. If the FDA does not comment on the IND, we, or our commercial partner, may begin clinical trials.

16

Clinical trials are subject to oversight by institutional review boards and the FDA. In addition, our proposed clinical studies will require review from the Recombinant DNA Advisory Committee, or RAC, which is the advisory board to the National Institutes of Health, or NIH, focusing on clinical trials involving gene transfer. We will typically submit a proposed clinical protocol and other product-related information to the RAC three to six months prior to the expected IND filing date.

Clinical trials:

Clinical trials are lengthy and are typically conducted in three sequential phases, but the phases may overlap or be combined. Each trial must be reviewed and approved by an independent ethics committee or institutional review board before it can begin. Phase I usually involves the initial introduction of the investigational drug into healthy volunteers or patients to evaluate certain factors, including its safety, dosage tolerance and, if possible, to gain an early indication of its effectiveness. Phase II usually involves trials in a limited patient population to evaluate dosage tolerance and appropriate dosage, identify possible adverse effects and safety risks, and evaluate preliminarily the efficacy of the drug for specific indications. Phase III trials usually further evaluate clinical efficacy and test further for safety by using the drug in its final form in an expanded patient population. Later clinical trials may fail to support the findings of earlier trials, which would delay, limit or prevent regulatory approvals.

While we have stated our intention to file IND applications during the next several years, this is only a statement of intent, and we may not be able to do so because the associated product candidates may not meet the necessary preclinical requirements. In addition, there can be no assurance that, once filed, an IND application will result in the actual initiation of clinical trials.

We may not be able to find acceptable patients or may experience delays in enrolling patients for our clinical trials. The FDA or we may suspend our clinical trials at any time if either believes that we are exposing the subjects participating in these trials to unacceptable health risks. The FDA or institutional review boards and/or institutional biosafety committees at the medical institutions and healthcare facilities where we sponsor clinical trials may suspend any trial indefinitely if they find deficiencies in the conduct of these trials. The FDA and institutional review boards may also require large numbers of patients, and the FDA may require that we repeat a clinical trial.

The results of early Phase I trials are based on a small number of patients over a short period of time, and our success may not be indicative of results in a large number of patients or of long-term efficacy. The results in early phases of clinical testing are based upon limited numbers of patients and a limited follow-up period. For example, the results from the Phase I clinical trial of our ZFP Therapeutic, SB-509 product, are expected to be available in the first half of 2006. The primary end point of the trial is clinical and laboratory safety, however we expect to be able to collect some preliminary efficacy data. Typically, our Phase I clinical trials for indications of safety enroll less than 50 patients. We anticipate that our Phase II clinical trials for efficacy would typically enroll approximately 100 patients. Actual results with more data points may not confirm favorable results from our earlier stage trials. A number of companies in the pharmaceutical and biotechnology industries have suffered significant setbacks in late stage clinical trials even after achieving promising results in earlier stage clinical trials. In addition, we do not yet know if early results will have a lasting effect. If a larger population of patients does not experience positive results, or if these results do not have a lasting effect, our products may not receive approval from the FDA. Failure to demonstrate the safety and effectiveness of our gene based products in larger patient populations could have a material adverse effect on our business that would cause our stock price to decline significantly.

17

We cannot predict whether or when we will obtain regulatory approval to commercialize our product candidates, therefore we cannot predict the timing of any future revenue from these product candidates. We cannot commercialize any of our product candidates to generate revenue until the appropriate regulatory authorities have reviewed and approved the applications for the product candidates. We cannot assure you that the regulatory agencies will complete their review processes in a timely manner or that we will obtain regulatory approval for any product candidate that we, or our collaborators, develop. Satisfaction of regulatory requirements typically takes many years, is dependent upon the type, complexity and novelty of the product and requires the expenditure of substantial resources. Regulatory approval processes outside the United States include all of the risks associated with the FDA approval process. In addition, we may experience delays or rejections based upon additional government regulation from future legislation or administrative action or changes in FDA policy during the period of product development, clinical trials and FDA regulatory review.

Our gene regulation and gene modification technology is relatively new, and if we are unable to use this technology in all our intended applications, it would limit our revenue opportunities. Our technology involves a relatively new approach to gene regulation and gene modification. Although we have generated ZFP TFs for hundreds of gene sequences, we have not created ZFP TFs for all gene sequences and may not be able do so, which could limit the usefulness of our technology. In addition, while we have demonstrated the function of engineered ZFP TFs in mammalian cell culture, yeast, insects, plants, and animals, we have not yet done so in humans, and the failure to do so could restrict our ability to develop commercially viable products. If we, and our collaborators or strategic partners, are unable to extend our results to new commercially important genes, experimental animal models, and human clinical studies, we may be unable to use our technology in all its intended applications. Also, delivery of ZFP TFs and ZFNs into cells and organisms, including humans, in these and other environments is limited by a number of technical hurdles, which we may be unable to surmount. This is a particular challenge for therapeutic applications of our technology that will require the use of gene transfer systems that may not be effective for the delivery of our ZFP TFs or ZFNs in a particular therapeutic application.

The expected value and utility of our ZFP TFs and ZFNs is in part based on our belief that the targeted or specific regulation of gene expression and targeted gene modification may enable us to develop a new therapeutic approach as well as to help scientists better understand the role of human, animal, and other genes in disease and to aid their efforts in drug discovery and development. We also believe that the regulation of gene expression and targeted gene insertion will have utility in agricultural applications. There is only a limited understanding of the role of specific genes in all these fields. Life sciences companies have developed or commercialized only a few products in any of these fields based on results from genomic research or the ability to regulate gene expression. We, our collaborators, or our strategic partners may not be able to use our technology to identify and validate drug targets or to develop commercial products in the intended markets.

We are currently engaged in the research and development of a new application of our technology platform: ZFP-mediated gene modification using ZFNs to effect either gene correction or gene disruption. Using this technique, Sangamo scientists have engineered gene-specific ZFPs to cut DNA at a specific site within a target gene, and to then to either correct the adjacent sequences with newly synthesized DNA copied from an introduced DNA template, gene correction, or to rejoin the two ends of the break which frequently results in the disruption of the gene’s function. In so doing, we are attempting to “correct” an abnormal or disease-related mutation or DNA sequence or to disrupt a gene that is involved in disease pathology. ZFP-mediated gene modification is at an early stage of development. Our scientists have shown ZFP-mediated gene modification to work in isolated cells; however, a significant amount of additional research will be needed before this technique can be evaluated in animals or plants and subsequently tested for applications in human healthcare and plant agriculture.

We may be unable to license gene transfer technologies that we may need to commercialize our ZFP TF technology. In order to regulate a gene in a cell, the ZFP TF or ZFN must be efficiently delivered to the cell. We have licensed certain gene transfer technologies for use with our Enabling Technologies, which are ZFP TFs and ZFNs used in pharmaceutical discovery research and protein production. We are evaluating these systems and other technologies which may need to be used in the delivery of ZFP TFs or ZFNs into cells for in vitro and in vivo applications, including ZFP Therapeutics. However, we may not be able to license the gene transfer technologies required to develop and commercialize our ZFP Therapeutics. We have not developed our own gene transfer technologies, and we rely on our ability to enter into license agreements to provide us with rights to the necessary gene transfer technology. The inability to obtain a license to use gene transfer technologies with entities which own such technology on reasonable commercial terms, if at all, could delay or prevent the preclinical evaluation, clinical testing, and/or commercialization of our therapeutic product candidates.

We do not currently have the infrastructure or capability to manufacture therapeutic products on a commercial scale. In order for us to commercialize these products directly, we would need to develop, or obtain through outsourcing arrangements, the capability to execute all of these functions. If we are unable to develop or otherwise obtain the requisite preclinical, clinical, regulatory, manufacturing, marketing, and sales capabilities, we would be unable to directly commercialize our therapeutics products which would limit our future growth.

18

Even if our technology proves to be effective, it still may not lead to commercially viable products. Even if our collaborators or strategic partners are successful in using our ZFP technology in drug discovery, protein production, therapeutic development, or plant agriculture, they may not be able to commercialize the resulting products or may decide to use other methods competitive with our technology. To date, no company has received marketing approval or has developed or commercialized any therapeutic or agricultural products based on our technology. The failure of our technology to provide safe, effective, useful, or commercially viable approaches to the discovery and development of these products would significantly limit our business and future growth and would adversely affect our value.

Even if our product development efforts are successful and even if the requisite regulatory approvals are obtained, our ZFP Therapeutics may not gain market acceptance among physicians, patients, healthcare payers and the medical community. A number of additional factors may limit the market acceptance of products including the following:

Adverse events in the field of gene therapy may negatively impact regulatory approval or public perception of our potential products. Our potential therapeutic products are delivered to patients as gene-based drugs, or gene therapy. The clinical and commercial success of our potential products will depend in part on public acceptance of the use of gene therapy for the prevention or treatment of human diseases. Public attitudes may be influenced by claims that gene therapy is unsafe, and, consequently, our products may not gain the acceptance of the public or the medical community. Negative public reaction to gene therapy in general could result in greater government regulation and stricter labeling requirements of gene therapy products, including any of our products, and could cause a decrease in the demand for any products we may develop.

Our stock price is also influenced by public perception. Reports of serious adverse events in a retroviral gene transfer trial for infants with X-linked severe combined immunodeficiency (X-linked SCID) in France and subsequent FDA actions putting related trials on hold in the United States had a significant negative impact on the public perception and stock price of certain companies involved in gene therapy. Stock prices of these companies declined whether or not the specific company was involved with retroviral gene transfer for the treatment of infants with SCID, or whether the specific company’s clinical trials were placed on hold in connection with these events.

Other potential adverse events in the field of gene therapy may occur in the future that could result in greater governmental regulation of our potential products and potential regulatory delays relating to the testing or approval of our potential products.

We are at the development phase of operations and may not succeed or become profitable. We began operations in 1995 and are in the early phases of ZFP Therapeutic product development. We have incurred significant losses and our net losses to date and our revenues have been generated from Enabling Technology agreements, strategic partners, and federal government research grants. Since 2004, we have placed more emphasis on higher-value therapeutic product development and related strategic partnerships. This shift in emphasis has the potential to increase the return on investment to our stockholders by allocating capital resources to higher value, therapeutic product development activities. At the same time, it increases our financial risk by increasing expenses associated with product development. In addition, the preclinical or clinical failure of any single product may have a significant effect on the actual or perceived value of our shares. Our business is subject to all of the risks inherent in the development of a new technology, which include the need to:

19

Commercialization of our technologies will depend, in part, on strategic partnering with other companies. If we are not able to find strategic partners in the future or our strategic partners do not diligently pursue product development efforts, we may not be able to develop our technologies or products, which could slow our growth and decrease our value. We expect to rely, to some extent, on our strategic partners to provide funding in support of our research and to perform independent research and preclinical and clinical testing. Our technology is broad based, and we do not currently possess the resources necessary to fully develop and commercialize potential products that may result from our technologies or the resources or capabilities to complete the lengthy marketing approval processes that may be required for the products. Therefore, we plan to rely on strategic partnerships to help us develop and commercialize ZFP Therapeutic products. If those partners are unable or unwilling to advance our programs, or if they do not diligently pursue product approval, this may slow our progress and defer our revenues. Our partners may sublicense or abandon development programs or we may have disagreements with our partners, which would cause associated product development to slow or cease. There can be no assurance that we will be able to establish additional strategic collaborations for ZFP Therapeutic product development. We may require significant time to secure additional collaborations or strategic partners because we need to effectively market the benefits of our technology to these future collaborators and strategic partners, which use the time and efforts of research and development personnel and our management. Further, each collaboration or strategic partnering arrangement will involve the negotiation of terms that may be unique to each collaborator or strategic partner. These business development efforts may not result in a collaboration or strategic partnership.

The loss of our current or any future strategic partnering agreements would not only delay or terminate the potential development or commercialization of products we may derive from our technologies, but it may also delay or terminate our ability to test ZFP TFs for specific genes. If any strategic partner fails to conduct the collaborative activities successfully and in a timely manner, the preclinical or clinical development or commercialization of the affected product candidates or research programs could be delayed or terminated.

Our existing strategic partnering agreements are based on the achievement of milestones. Under the strategic partnering agreements, we expect to receive revenue for the research and development of a ZFP Therapeutic product and based on achievement of specific milestones. Achieving these milestones will depend, in part, on the efforts of our strategic partner as well as our own. In contrast, our historic Enabling Technology agreements only pay us to supply ZFP TFs for the collaborator’s independent use, rather than for future results of the collaborator’s efforts. If we, or any strategic partner, fail to meet specific milestones, then the strategic partnership may be terminated, which could decrease our revenues.

If our competitors develop, acquire, or market technologies or products that are more effective than ours, this would reduce or eliminate our commercial opportunity. Any products that we or our collaborators or strategic partners develop by using our ZFP technology platform will enter into highly competitive markets. Even if we are able to generate ZFP Therapeutics that are safe and effective for their intended use, competing technologies may prove to be more effective or less expensive, which, to the extent these competing technologies achieve market acceptance, will limit our revenue opportunities. In some cases, competing technologies have proven to be satisfactorily effective and less expensive, as has been the case with technologies competitive with our Enabling Technology®. The effectiveness of these competing products has reduced the revenues generated by our Enabling Technology. Competing technologies may include other methods of regulating gene expression or modifying genes. ZFP TFs and ZFNs have broad application in the life sciences and compete with a broad array of new technologies and approaches being applied to genetic research by many companies. Competing proprietary technologies with our product development focus include:

20

Accordingly, our competitors may succeed in obtaining patent protection or commercializing products before us. In addition, any products that we develop may compete with existing products or services that are well established in the marketplace.

Our collaborators or strategic partners may decide to adopt alternative technologies or may be unable to develop commercially viable products with our technology, which would negatively impact our revenues and our strategy to develop these products. Our collaborators or strategic partners may adopt alternative technologies, which could decrease the marketability of ZFP technology. Additionally, because many of our collaborators or strategic partners are likely to be working on more than one development project, they could choose to shift their resources to projects other than those they are working on with us. If they do so, that would delay our ability to test our technology and would delay or terminate the development of potential products based on our ZFP technology. Further, our collaborators and strategic partners may elect not to develop products arising out of our collaborative and strategic partnering arrangements or to devote sufficient resources to the development, manufacturing, marketing, or sale of these products. If any of these events occur, we may not be able to develop our technologies or commercialize our products.

We anticipate continuing to incur operating losses for the next several years. If material losses continue for a significant period, we may be unable to continue our operations. We have generated operating losses since we began operations in 1995. The extent of our future losses and the timing of profitability are uncertain, and we expect to incur losses for the foreseeable future. We have been engaged in developing our ZFP TF technology since inception, which has and will continue to require significant research and development expenditures. To date, we have generated our revenues from Universal GeneTools® collaboration agreements, strategic partnering agreements, and federal government research grants. As of March 31, 2005, we had an accumulated deficit of approximately $100.7 million. We expect to incur losses for the foreseeable future. These losses will increase as we expand and extend our research and development activities into human therapeutic product development. If the time required to generate significant product revenues and achieve profitability is longer than we currently anticipate, we may not be able to sustain our operations.

21

We may be unable to raise additional capital, which would harm our ability to develop our technology and products. We have incurred significant operating losses and negative operating cash flows since inception and have not achieved profitability. We expect capital outlays and operating expenditures to increase over the next several years as we expand our infrastructure and research and ZFP Therapeutic product development activities. While we believe our financial resources will be adequate to sustain our current operations at least through 2006, we may seek additional sources of capital through equity or debt financing. In addition, as we focus our efforts on proprietary human therapeutics, we will need to seek FDA approval of potential products, a process that could cost in excess of $100 million per product. We cannot be certain that we will be able to obtain financing on terms acceptable to us, or at all. If adequate funds are not available, our business and our ability to develop our technology and ZFP Therapeutic products would be harmed.

Our stock price has been volatile and may continue to be volatile, which could result in substantial losses for investors. During the past two years, our common stock price has fluctuated significantly. Volatility in our common stock could cause stockholders to incur substantial losses. An active public market for our common stock may not be sustained, and the market price of our common stock may continue to be highly volatile. The market price of our common stock has fluctuated significantly in response to the following factors, some of which are beyond our control:

Our common stock is thinly traded, which means large transactions in our common stock may be difficult to conduct in a short time frame. We have a low volume of daily trades in our common stock on the Nasdaq National Market. For example, the average daily trading volume in our common stock on the Nasdaq National Market over the ten-day trading period prior to May 9, 2005 was less than 48,000 shares per day. Any large transactions in our common stock may be difficult to conduct and may cause significant fluctuations in the price of our common stock.

Failure to attract, retain, and motivate skilled personnel and cultivate key academic collaborations will delay our product development programs and our research and development efforts. We are a small company with 56 full-time employees as of April 29, 2005, and our success depends on our continued ability to attract, retain, and motivate highly qualified management and scientific personnel and our ability to develop and maintain important relationships with leading research and academic institutions and scientists. Competition for personnel and academic and other research collaborations is intense. The success of our technology development programs depends on our ability to attract and retain highly trained personnel and we have experienced a rate of employee turnover that we believe is typical of emerging biotechnology companies. If we lose the services of personnel with the necessary skills, it could significantly impede the achievement of our research and development objectives. We are not presently aware of any plans of specific employees to retire or otherwise leave the company. If we fail to negotiate additional acceptable collaborations with academic and other research institutions and scientists, or if our existing collaborations are unsuccessful, our ZFP Therapeutic development programs may be delayed or may not succeed.

If conflicts arise between us and our collaborators, strategic partners, scientific advisors, or directors, these parties may act in their self-interest, which may limit our ability to implement our strategies. If conflicts arise between our corporate or academic collaborators, strategic partners, or scientific advisors or directors and us, the other party may act in its self-interest, which may limit

22

our ability to implement our strategies. Some of our academic collaborators and strategic partners are conducting multiple product development efforts within each area that is the subject of the collaboration with us. Our collaborators or strategic partners, however, may develop, either alone or with others, products in related fields that are competitive with the products or potential products that are the subject of these collaborations. Competing products, either developed by the collaborators or strategic partners or to which the collaborators or strategic partners have rights, may result in the withdrawal of partner support for our product candidates.

Some of our collaborators or strategic partners could also become competitors in the future. Our collaborators or strategic partners could develop competing products, preclude us from entering into collaborations with their competitors, fail to obtain timely regulatory approvals, terminate their agreements with us prematurely, or fail to devote sufficient resources to the development and commercialization of products. Any of these developments could harm our product development efforts.

Because it is difficult and costly to protect our proprietary rights, and third parties have filed patent applications that are similar to ours, we cannot ensure the proprietary protection of our technologies and products. Our commercial success will depend in part on obtaining patent protection of our technology and successfully defending any of our patents which may be challenged. The patent positions of pharmaceutical and biotechnology companies can be highly uncertain and can involve complex legal and factual questions. No consistent policy regarding the breadth of claims allowed in biotechnology patents has emerged to date. Accordingly, we cannot predict the breadth of claims allowed in patents we own or license.

We are a party to various license agreements that give us rights under specified patents and patent applications. Our current licenses, as our future licenses frequently will, contain performance obligations. If we fail to meet those obligations, the licenses could be terminated. If we are unable to continue to license these technologies on commercially reasonable terms, or at all, we may be forced to delay or terminate our product development and research activities. With respect to our present and any future sublicenses, since our rights derive from those granted to our sublicensor, we are subject to the risk that our sublicensor may fail to perform its obligations under the master license or fail to inform us of useful improvements in, or additions to, the underlying intellectual property owned by the original licensor.

We are unable to exercise the same degree of control over intellectual property that we license from third parties as we exercise over our internally developed intellectual property. We generally do not control the prosecution of patent applications that we license from third parties; therefore, the patent applications may not be prosecuted in a timely manner.

The degree of future protection for our proprietary rights is uncertain, and we cannot ensure that:

Others have filed and in the future are likely to file patent applications that are similar to ours. We are aware that there are academic groups and other companies that are attempting to develop technology that is based on the use of zinc finger and other DNA binding proteins, and that these groups and companies have filed patent applications. Several patents have been issued, although we have no current plans to use the associated inventions. If these or other patents issue, it is possible that the holder of any patent or patents granted on these applications may bring an infringement action against our collaborators, strategic partners, or us claiming damages and seeking to enjoin commercial activities relating to the affected products and processes. The costs of litigating the claim could be substantial. Moreover, we cannot predict whether we, our collaborators, or strategic partners would prevail in any actions. In addition, if the relevant patent claims were upheld as valid and enforceable and our products or processes were found to infringe the patent or patents, we could be prevented from making, using, or selling the relevant product or process unless we could obtain a license or were able to design around the patent claims. We can give no assurance that such a license would be available on commercially reasonable

23

terms, or at all, or that we would be able to successfully design around the relevant patent claims. There may be significant litigation in the genomics industry regarding patent and other intellectual property rights, which could subject us to litigation. If we become involved in litigation, it could consume a substantial portion of our managerial and financial resources.

We cannot guarantee that third parties will not challenge our intellectual property. One of our licensed patents, European Patent No. 0 682 699, entitled “Functional Domains in Flavobacterium okeanokoites Restriction Endonuclease” was granted on May 7, 2003 and forms the basis of Regional Phase patents in France, Germany, Great Britain, Ireland and Switzerland. The granted claims of the patent cover technologies used in our programs in targeted recombination and gene correction. On February 6, 2004, a Notice of Opposition to the European Patent was filed on behalf of Cellectis, a French company. We cannot predict the outcome of these Opposition proceedings. If the claims of this European patent were to be invalidated, it would not affect our ability to practice our targeted recombination and gene correction programs in Europe. It would, however, limit our ability to exclude potential competitors in the field of targeted recombination and gene correction in Europe.

Moreover, we also hold licenses to six US patents to the technology covered by the opposed European patent, and hold licenses to related applications pending in Canada and Japan. Accordingly, any effects of the opposition, up to and including invalidation of the European patent, would be restricted to Europe and would have little, if any, material adverse effect on our business.

We rely on trade secrets to protect technology where we believe patent protection is not appropriate or obtainable. Trade secrets, however, are difficult to protect. While we require employees, academic collaborators, and consultants to enter into confidentiality agreements, we may not be able to adequately protect our trade secrets or other proprietary information or enforce these confidentiality agreements.

Our collaborators, strategic partners, and scientific advisors have rights to publish data and information in which we may have rights. If we cannot maintain the confidentiality of our technology and other confidential information in connection with our collaborations and strategic partnerships, then we may not be able to receive patent protection or protect our proprietary information.

Regulatory approval, if granted, may be limited to specific uses or geographic areas, which could limit our ability to generate revenues. Regulatory approval will be limited to the indicated use for which we can market a product. Further, once regulatory approval for a product is obtained, the product and its manufacturer are subject to continual review. Discovery of previously unknown problems with a product or manufacturer may result in restrictions on the product, manufacturer, and manufacturing facility, including withdrawal of the product from the market. In Japan and Europe, regulatory agencies also set or approve prices.

Even if regulatory clearance of a product is granted, this clearance is limited to those specific states and conditions for which the product is useful, as demonstrated through clinical trials. We cannot ensure that any ZFP Therapeutic product developed by us, alone or with others, will prove to be safe and effective in clinical trials and will meet all of the applicable regulatory requirements needed to receive marketing clearance in a given country.

Outside the United States, our ability to market a product is contingent upon receiving a marketing authorization from the appropriate regulatory authorities, so we cannot predict whether or when we would be permitted to commercialize our product. These foreign regulatory approval processes include all of the risks associated with FDA clearance described above.

Our collaborations with outside scientists may be subject to change, which could limit our access to their expertise. We work with scientific advisors and collaborators at academic research institutions. These scientists are not our employees and may have other commitments that would limit their availability to us. Although our scientific advisors generally agree not to do competing work, if a conflict of interest between their work for us and their work for another entity arises, we may lose their services. Although our scientific advisors and academic collaborators sign agreements not to disclose our confidential information, it is possible that some of our valuable proprietary knowledge may become publicly known through them.

Laws or public sentiment may limit the production of genetically modified agricultural products in the future, and these laws could reduce our ability to sell these products. Genetically modified products are currently subject to public debate and heightened regulatory scrutiny, either of which could prevent or delay production of agricultural products. We may develop genetically modified agricultural products for ourselves or with our strategic partners. The field-testing, production, and marketing of genetically modified plants and plant products are subject to federal, state, local, and foreign governmental regulation. Regulatory agencies administering existing or future regulations or legislation may not allow production and marketing of our genetically modified products in a timely manner or under technically or commercially feasible conditions. In addition, regulatory action or private litigation could result in expenses, delays, or other impediments to our product development programs or the commercialization of resulting products.

The FDA currently applies the same regulatory standards to foods developed through genetic engineering as those applied to foods developed through traditional plant breeding. Genetically engineered food products, however, will be subject to pre-market review if

24

these products raise safety questions or are deemed to be food additives. Governmental authorities could also, for social or other purposes, limit the use of genetically modified products created with our gene regulation technology.

Even if we are able to obtain regulatory approval for genetically modified products, our success will also depend on public acceptance of the use of genetically modified products including drugs, plants, and plant products. Claims that genetically modified products are unsafe for consumption or pose a danger to the environment may influence public attitudes. Our genetically modified products may not gain public acceptance. The subject of genetically modified organisms has received negative publicity in the United States and particularly in Europe, and such publicity has aroused public debate. The adverse publicity in Europe could lead to greater regulation and trade restrictions on imports of genetically altered products. Similar adverse public reaction in the United States to genetic research and its resulting products could result in greater domestic regulation and could decrease the demand for our technology and products.

If we use biological and hazardous materials in a manner that causes injury or violates laws, we may be liable for damages. Our research and development activities involve the controlled use of potentially harmful biological materials as well as hazardous materials, chemicals, and various radioactive compounds typically employed in molecular and cellular biology. We routinely use cells in culture and gene delivery vectors, and we employ small amounts of radioisotopes in trace experiments. Although we maintain up-to-date licensing and training programs, we cannot completely eliminate the risk of accidental contamination or injury from the use, storage, handling, or disposal of these materials. In the event of contamination or injury, we could be held liable for damages that result, and any liability could exceed our resources. We currently carry insurance covering claims arising from our use of these materials. However, if we are unable to maintain our insurance coverage at a reasonable cost and with adequate coverage, our insurance may not cover any liability that may arise. We are subject to federal, state, and local laws and regulations governing the use, storage, handling, and disposal of these materials and specified waste products. To date, we have not experienced significant costs in complying with regulations regarding the use of these materials.

Anti-takeover provisions in our certificate of incorporation and Delaware law could make an acquisition of the Company more difficult and could prevent attempts by our stockholders to remove or replace current management. Anti-takeover provisions of Delaware law, our certificate of incorporation and our bylaws and may discourage, delay or prevent a change in control of our company, even if a change in control would be beneficial to our stockholders. In addition, these provisions may frustrate or prevent any attempts by our stockholders to replace or remove our current management by making it more difficult for stockholders to replace members of our board of directors. In particular, under our certificate of incorporation our board of directors may issue up to 5,000,000 shares of preferred stock with rights and privileges that might be senior to our common stock, without the consent of the holders of the common stock. Moreover, without any further vote or action on the part of the stockholders, the board of directors would have the authority to determine the price, rights, preferences, privileges, and restrictions of the preferred stock. This preferred stock, if it is ever issued, may have preference over, and harm the rights of, the holders of common stock. Although the issuance of this preferred stock would provide us with flexibility in connection with possible acquisitions and other corporate purposes, this issuance may make it more difficult for a third party to acquire a majority of our outstanding voting stock. Similarly, our authorized but unissued common stock is available for future issuance without stockholder approval.

In addition, our certificate of incorporation:

We are also subject to Section 203 of the Delaware General Corporation Law, which provides, subject to certain exceptions, that if a person acquires 15% of our voting stock, the person is an “interested stockholder” and may not engage in “business combinations” with us for a period of three years from the time the person acquired 15% or more or our voting stock.

Insiders have substantial control over Sangamo and could delay or prevent a change in corporate control. The interest of management could conflict with the interest of our other stockholders. Our executive officers and directors beneficially own, in the aggregate, approximately 29% of our outstanding common stock. As a result, these stockholders, if they choose to act together, will be able to have a material impact on all matters requiring stockholder approval, including the election of directors and approval of significant corporate transactions. This could have the effect of delaying or preventing a change of control of Sangamo, which in turn could reduce the market price of our stock.

25

ITEM 3. QUANTITATIVE AND QUALITATIVE DISCLOSURES ABOUT MARKET RISK

Our exposure to market risk for changes in interest rates relates primarily to our cash equivalents and investments. The investments are available-for-sale. We do not use derivative financial instruments in our investment portfolio. We attempt to ensure the safety and preservation of our invested funds by limiting default and market risks. Our cash and investments policy emphasizes liquidity and preservation of principal over other portfolio considerations. We select investments that maximize interest income to the extent possible within these guidelines. We satisfy liquidity requirements by investing excess cash in securities with different maturities to match projected cash needs and limit concentration of credit risk by diversifying our investments among a variety of high credit-quality issuers. We mitigate default risk by investing in only investment-grade securities. The portfolio includes marketable securities with active secondary or resale markets to ensure portfolio liquidity. All investments have a fixed interest rate and are carried at market value, which approximates cost.

     The following table represents the fair value balance of our cash, cash equivalents and marketable securities by year of expected maturity that are subject to interest rate risk as of March 31, 2005 (in thousands, except for interest rates):

26

ITEM 4. CONTROLS AND PROCEDURES

     (a) Evaluation of Disclosure Controls and Procedures

     The Company’s management, with the participation of the Company’s Chief Executive Officer and Principal Financial Officer, evaluated the effectiveness of the Company’s disclosure controls and procedures as of the end of the period covered by this report. Based on that evaluation, the Chief Executive Officer and Principal Financial Officer concluded that the Company’s disclosure controls and procedures as of the end of the period covered by this report have been designed and are functioning effectively to provide reasonable assurance that the information required to be disclosed by the Company in reports filed under the Securities Exchange Act of 1934 is recorded, processed, summarized and reported within the time periods specified in the SEC’s rules and forms.

     (b) Change in Internal Control over Financial Reporting

     No change in the Company’s internal control over financial reporting occurred during the Company’s most recent fiscal quarter that has materially affected, or is reasonably likely to materially affect, the Company’s internal control over financial reporting.

PART II. OTHER INFORMATION

ITEM 1. LEGAL PROCEEDINGS

     We are not party to any material litigation.

ITEM 2. UNREGISTERED SALES OF EQUITY SECURITIES AND USE OF PROCEEDS

     The effective date of our first Registration Statement on Form S-1 filed under the Securities Act of 1933, as amended, relating to the initial public offering of our common stock was April 6, 2000. On the same date, we signed an underwriting agreement with Lehman Brothers, Chase H&Q, ING Barings LLC, and William Blair & Co., the managing underwriters for the initial public offering and the representatives of the underwriters named in the underwriting agreement, for the initial public offering of 3,500,000 shares of our common stock at an initial public offering price of $15 per share. The offering commenced on April 6, 2000 and was closed on April 11, 2000. The initial public offering resulted in gross proceeds of $52.5 million. We received net proceeds of $48.8 million after deducting underwriting discounts of $3.7 million. Expenses related to the offering totaled approximately $1.4 million. None of Sangamo’s net proceeds from the initial public offering were paid directly or indirectly to any director, officer, general partner of Sangamo or their associates, persons owning 10% or more of any class of equity securities of Sangamo, or an affiliate.

     From the time of receipt through March 31, 2005, Sangamo has used the net proceeds from its initial public offering of common stock to invest in short-term and long-term, interest bearing, investment-grade securities and has used its existing cash balances to fund general operations. The proceeds are being used for general corporate purposes, including working capital and product development. A portion of the net proceeds will also be used to acquire or invest in complementary businesses or products or to obtain the right to use complementary technologies. Sangamo has no agreements or commitments with respect to any such acquisition and is not currently engaged in any material negotiations with respect to any such transaction.

ITEM 6. EXHIBITS

     (a) Exhibits:

27

SIGNATURES

     Pursuant to the requirements of the Securities and Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned thereunto duly authorized.

SANGAMO BIOSCIENCES, INC. Dated: May 10, 2005

28

Exhibit 31.1

CERTIFICATION

I, Edward O. Lanphier II, certify that:

Exhibit 31.2

CERTIFICATION

I, Greg S. Zante, certify that:

Exhibit 32.1

Certification Pursuant to 18 U.S.C. §1350, as Adopted
Pursuant to §906 of the Sarbanes-Oxley Act of 2002

Each of the undersigned hereby certifies pursuant to 18 U.S.C. § 1350, as adopted pursuant to § 906 of the Sarbanes-Oxley Act of 2002 in his capacity as an officer of Sangamo BioSciences, Inc. (the “Company”), that:

(1) the Quarterly Report of the Company on Form 10-Q for the quarterly period ended March 31, 2005, as filed with the Securities and Exchange Commission (the “Report”) fully complies with the requirements of Section 13(a) or 15(d) of the Securities Exchange Act of 1934; and

(2) the information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company.