Allogene Therapeutics, Inc.

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Unless the context requires otherwise, references in this report to “Allogene,” the “Company,” “we,” “us” and “our” refer to Allogene Therapeutics, Inc.

SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This Annual Report contains forward-looking statements. The forward-looking statements are contained principally in the sections entitled “Business,” “Risk Factors,” and “Management’s Discussion and Analysis of Financial Condition and Results of Operations”. These statements relate to future events or to our future financial performance and involve known and unknown risks, uncertainties and other factors which may cause our actual results, performance or achievements to be materially different from any future results, performance or achievements expressed or implied by the forward-looking statements. Forward-looking statements include, but are not limited to, statements about:

•the success, cost, timing and potential indications of our product development activities and clinical trials;

•the timing of the initiation, enrollment and completion of planned clinical trials in the United States and foreign countries;

•our ability to obtain and maintain regulatory approval of our product candidates in any of the indications for which we plan to develop them, and any related restrictions, limitations, and/or warnings in the label of an approved product candidate;

•our ability to obtain funding for our operations, including funding necessary to complete the clinical trials of any of our product candidates;

•our ability and plans to research, develop, manufacture and commercialize our product candidates;

•our ability to attract and retain collaborators with development, regulatory and commercialization expertise;

•the size of the markets for our product candidates, and our ability to serve those markets;

•our ability to successfully commercialize our product candidates;

•the rate and degree of market acceptance of our product candidates;

•our ability to develop and maintain sales and marketing capabilities, whether alone or with potential future collaborators;

•regulatory developments in the United States and foreign countries;

•our ability to contract with and the performance of our and our collaborators’ third-party suppliers and manufacturers;

•our ability to develop and successfully operate our own manufacturing facility;

•the success of competing therapies that are or become available;

•our ability to attract and retain key scientific or management personnel;

•the accuracy of our estimates regarding expenses, future revenues, capital requirements and needs for additional financing;

•our use of cash and other resources; and

•our expectations regarding our ability to obtain and maintain intellectual property protection for our product candidates and our ability to operate our business without infringing on the intellectual property rights of others.

In some cases, you can identify these statements by terms such as “anticipate,” “believe,” “could,” “estimate,” “expects,” “intend,” “may,” “plan,” “potential,” “predict,” “project,” “should,” “will,” “would” or the negative of those terms, and similar expressions that convey uncertainty of future events or outcomes. These forward-looking statements reflect our management’s beliefs and views with respect to future events and are based on estimates and assumptions as of the date of this report and are subject to risks and uncertainties. In addition, statements that “we believe” and similar statements reflect our beliefs and opinions on the relevant subject. These statements are based upon information available to us as of the date of this Annual Report, and while we believe such information forms a reasonable basis for such statements, such information may be limited or incomplete, and our statements should not be read to indicate that we have conducted an exhaustive inquiry into, or review of, all potentially available relevant information. These statements are inherently uncertain and investors are cautioned not to unduly rely upon these statements. We discuss many of the risks associated with the forward-looking statements in this Annual Report in greater detail under the heading “Risk Factors.” Moreover, we operate in a very competitive and rapidly changing environment. New risks emerge from time to time. It is not possible for our management to predict all risks, nor can we assess the impact of all factors on our business or the extent to which any factor, or combination of factors, may cause actual results to differ materially from those contained in any forward-looking statements we may make. Given these uncertainties, you should not place undue reliance on these forward-looking statements.

You should carefully read this Annual Report and the documents that we reference in this Annual Report and have filed as exhibits to this Annual Report completely and with the understanding that our actual future results may be materially different from what we expect. We qualify all of the forward-looking statements in this Annual Report by these cautionary statements.

Except as required by law, we assume no obligation to update these forward-looking statements publicly, or to update the reasons actual results could differ materially from those anticipated in any forward-looking statements, whether as a result of new information, future events or otherwise.

Trademarks and Trade names

This Annual Report contains references to our trademarks and to trademarks belonging to other entities. Solely for convenience, trademarks and trade names referred to in this Annual Report, including logos, artwork and other visual displays, may appear without the® or TM symbols, but such references are not intended to indicate, in any way, that their respective owners will not assert, to the fullest extent under applicable law, their rights thereto. We do not intend our use or display of other companies’ trade names or trademarks to imply a relationship with, or endorsement or sponsorship of us by, any other companies.

Below is a summary of the material factors that make an investment in our common stock speculative or risky. This summary does not address all of the risks that we face. Additional discussion of the risks summarized in this risk factor summary, and other risks that we face, can be found below under the heading “Risk Factors” under Item 1A of Part I of this Annual Report, and should be carefully considered, together with other information in this Annual Report before making investment decisions regarding our common stock.

Risks Related to Our Financial Position and Capital Needs

•We have incurred net losses in every period since our inception and anticipate that we will incur substantial net losses in the future.

•We will need substantial additional financing to develop our products and implement our operating plans. If we fail to obtain additional financing, we may be unable to complete the development and commercialization of our product candidates.

•We may fail to meet our publicly announced guidance or other expectations about our business, which would cause our stock price to decline.

Risks Related to Our Business and Industry

•Our product candidates are based on novel technologies, which makes it difficult to predict the time and cost of product candidate development and the likelihood of obtaining regulatory approval.

•Our business is highly dependent on the success of our lead product candidates. If we are unable to advance clinical development, obtain approval of and successfully commercialize our lead product candidates for the treatment of patients in approved indications, our business would be significantly harmed.

•Our product candidates may cause undesirable side effects or have other properties that have halted and could in the future halt their clinical development, prevent their regulatory approval, limit their commercial potential or result in significant negative consequences.

•Our clinical trials may fail to demonstrate the safety and efficacy of any of our product candidates, which would prevent or delay regulatory approval and commercialization.

•Risks related to serious adverse events (SAEs) in the discontinued fludarabine, cyclophosphamide, and ALLO-647 (FCA) arm of our ALPHA3 trial, including the Grade 5 SAE, could lead to regulatory actions, negative perceptions, and potential product liability claims.

•No CAR T therapy has been approved as a part of first-line consolidation strategy for the treatment of large B-cell lymphoma (LBCL) patients, which presents significant regulatory, commercial, and operational risks, and there is no assurance of success in this unproven setting.

•We may encounter substantial delays in our clinical trials, or may not be able to conduct our trials on the timelines we expect.

•If we encounter difficulties enrolling patients in our clinical trials, our clinical development activities could be delayed or otherwise adversely affected.

•We may fail to successfully manufacture our product candidates, operate our own manufacturing facility, or obtain regulatory approval to utilize or commercialize from our manufacturing facility or at a CDMO, which could adversely affect our clinical trials and the commercial viability of our product candidates.

•Reduced manufacturing operations may limit our ability to timely support our development programs.

•We face significant competition from other biotechnology and pharmaceutical companies, and our operating results will suffer if we fail to compete effectively.

•We are highly dependent on our key personnel, and if we are not successful in attracting and retaining highly qualified personnel, we may not be able to successfully implement our business strategy.

•Disruptions to the operations of the FDA, the SEC and other government agencies, including comparable foreign regulatory authorities, resulting from funding shortages, policy initiatives, staffing reductions or related uncertainty, could impair their ability to perform regulatory functions and negatively impact our business.

Risks Related to the Development of Our Product Candidates

•Our engineered allogeneic T cell product candidates represent a novel approach to cancer treatment and treatment of autoimmune diseases, which creates significant challenges for us.

•Gene-editing is a relatively new technology, and if we are unable to use this technology in our intended product candidates, our revenue opportunities will be materially limited.

•There is uncertainty regarding whether the use of fludarabine and cyclophosphamide (FC) without ALLO-647 will achieve sufficient lymphodepletion to support the efficacy of our allogeneic CAR T product candidate in the ALPHA3 trial.

•We are heavily reliant on our partners, Cellectis and Servier, for access to TALEN gene editing technology for the manufacturing and development of our oncology product candidates.

•We are heavily reliant on our partner, Foresight Diagnostics, for access to their CLARITY™ MRD test for identifying eligible patients for our ALPHA3 trial.

Risks Related to Our Reliance on Third Parties

•We rely and will continue to rely on third parties to conduct our clinical trials. If these third parties do not successfully carry out their contractual duties or meet expected deadlines, we may not be able to obtain regulatory approval of or commercialize our product candidates.

Risks Related to Government Regulation

•The FDA and other comparable foreign regulatory approval processes are lengthy and time-consuming, and we may experience significant delays in the clinical development and regulatory approval of our product candidates.

•The FDA or comparable foreign regulatory authorities may disagree with our regulatory plan and we may fail to obtain regulatory approval of our CAR T cell product candidates.

•If we, or our collaborators, are required by the FDA, or comparable foreign regulatory authorities, to obtain approval (or clearance, or certification) of a companion diagnostic device in connection with approval of one of our product candidates, and we, or our collaborators, do not obtain, or face delays in obtaining, approval (or clearance, or certification) of a companion diagnostic device, we will not be able to commercialize the product candidate, and our ability to generate revenue will be materially impaired.

Risks Related to Our Intellectual Property

•We depend on intellectual property licensed from third parties and termination of any of these licenses could result in the loss of significant rights, which would harm our business.

•If our efforts to protect the proprietary nature of the intellectual property related to our technologies are not adequate, we may not be able to compete effectively in our market.

Risks Related to Ownership of Our Common Stock

•The price of our stock has been and may continue to be volatile, and you could lose all or part of your investment.