Agios Reports Business Highlights and Second Quarter 2019 Financial Results Strong Topline Performance for IDH Inhibitors: TIBSOVO Net Revenue Increased 50% from Q1 2019 to $13.7M; IDHIFA Royalty Increased to $2.7M Achie

Agios Reports Business Highlights and Second Quarter 2019 Financial Results

Strong Topline Performance for IDH Inhibitors: TIBSOVO Net Revenue

Increased 50% from Q1 2019 to $13.7M; IDHIFA Royalty Increased to $2.7M

Achieved Important Expansion Opportunities for TIBSOVO Including sNDA

Approval in Frontline AML and Positive Phase 3 Trial in Previously Treated IDH1 Mutant Cholangiocarcinoma

AG-270 Phase 1 Dose Escalation Complete and Data Submitted to AACR-NOI-EORTC Conference; Program Advancing to Expansion Phase This Quarter

CAMBRIDGE, Mass., August 1, 2019 Agios Pharmaceuticals, Inc. (NASDAQ: AGIO), a leader in the field of cellular metabolism to

treat cancer and rare genetic diseases, today reported business highlights and financial results for the second quarter ended June 30, 2019.

In the second quarter we demonstrated our ability to execute across all areas of our business. Our commercial team continues to deliver on the AML

launch for TIBSOVO and prepare for our first potential solid tumor launch on the heels of the positive ClarIDHy study in cholangiocarcinoma, said Jackie Fouse, Ph.D., chief executive

officer at Agios. On the clinical side, we continued to broaden our IDH program into earlier lines of AML therapy and expand our PKR programs into new disease areas while enrolling the PK deficiency pivotal studies. In addition, we completed

dose escalation in our AG-270 Phase 1 trial and are on track to initiate the next phase of development. The great progress we made during the quarter keeps us on track to deliver on our remaining 2019

milestones and drive further value across our portfolio.

SECOND QUARTER 2019 HIGHLIGHTS & RECENT PROGRESS

KEY UPCOMING MILESTONES

The company plans to achieve the following key milestones in the remainder of 2019:

Rare Genetic Diseases:

ANTICIPATED 2019 DATA PRESENTATIONS

SECOND QUARTER 2019 FINANCIAL RESULTS

Revenue: Total revenue for the second quarter of 2019 was $26.2 million, which includes $13.7 million of net product revenue from U.S. sales

of TIBSOVO , $9.0 million in collaboration revenue and $2.7 million in royalty revenue from net global sales of IDHIFA under

our collaboration agreement with Celgene. This compares to revenue of $40.4 million for the second quarter of 2018, which included recognition of a $15 million milestone from Celgene related to Celgene s filing of an MAA to the EMA

for IDHIFA and $12.4 million from the signing of the CStone collaboration.

Sales: We began U.S. sales of TIBSOVO in the third quarter of 2018. Cost of sales were $0.3 million for the second quarter of 2019.

Research and Development (R&D) Expenses: R&D expenses were $107.4 million for the second quarter of 2019 compared to $86.7 million

for the second quarter of 2018. The increase in R&D expense was primarily attributable to vorasidenib Phase 3 low grade glioma trial start-up costs, the mitapivat pivotal program in PK deficiency and Phase

2 study in thalassemia, and clinical trial activity related to the ongoing Phase 1 trials for AG-270 and AG-636.

Selling, General and Administrative (SG&A) Expenses: SG&A expenses were $32.4 million for the second quarter of 2019 compared to

$26.6 million for the second quarter of 2018. The increase in SG&A expense was primarily attributable to costs to support commercialization of TIBSOVO and personnel costs related to

increased headcount.

Net Loss: Net loss was $109.9 million for the second quarter of 2019 compared to $68.7 million for the second

Cash Position and Guidance: Cash, cash equivalents and marketable securities as of June 30, 2019 were $624.0 million

compared to $805.4 million as of December 31, 2018. The net decrease of $181.4 million in cash position was primarily driven by net expenditures to fund operations, including a onetime cash expense of $19.2 million for bonus

payouts during the first quarter. The company expects that its cash, cash equivalents and marketable securities as of June 30, 2019, together with anticipated product and royalty revenue, anticipated interest income, and anticipated expense

reimbursements under our collaboration and license agreements, but excluding any additional program-specific milestone payments, will enable the company to fund its anticipated operating expenses and capital expenditure requirements through at least

CONFERENCE CALL INFORMATION

will host a conference call and live webcast with slides today at 8:00 a.m. ET to discuss second quarter 2019 financial results and recent business activities. To participate in the conference call, please dial 1-877-377-7098 (domestic) or 1-631-291-4547

(international) and refer to conference ID 9319039. The live webcast can be accessed under Events & Presentations in the Investors section of the company s website at www.agios.com. The archived webcast will be

available on the company s website beginning approximately two hours after the event.

Agios is focused on discovering and developing novel investigational medicines to treat cancer and rare genetic diseases through scientific leadership in the

field of cellular metabolism and adjacent areas of biology. In addition to an active research and discovery pipeline across both therapeutic areas, Agios has two approved oncology precision medicines and multiple first-in-class investigational therapies in clinical and/or preclinical development. All Agios programs focus on genetically identified patient populations, leveraging our knowledge of metabolism, biology and

genomics. For more information, please visit the company s website at www.agios.com.

About Agios/Celgene Collaboration

IDHIFA (enasidenib) and AG-270 are part of our

collaboration with Celgene Corporation. Under the terms of our 2010 collaboration agreement focused on cancer metabolism, Celgene has worldwide development and commercialization rights for

IDHIFA . Agios continues to conduct certain clinical development activities within the IDHIFA development program and is eligible to

receive reimbursement for those development activities and up to $80 million in remaining milestone payments, and royalties on any net sales. Celgene and Agios are currently co-commercializing IDHIFA in the U.S. Celgene will reimburse Agios for costs incurred for its co-commercialization efforts. AG-270 is part of

a 2016 global research collaboration agreement with Celgene focused on metabolic immuno-oncology. Celgene has the option to participate in a worldwide 50/50 cost and profit share with Agios, under which Agios is eligible for up to $169 million

in clinical and regulatory milestone payments for the program.

Cautionary Note Regarding Forward-Looking Statements

This press release contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Such forward-looking

statements include those regarding Agios plans, strategies and expectations for its and its collaborator s preclinical, clinical and commercial advancement of its drug development programs including TIBSOVO , IDHIFA , vorasidenib, mitapivat, AG-270 and AG-636; the

potential benefits of Agios product candidates; its key milestones for 2019; its plans regarding future data presentations; its financial guidance regarding the period in which it will have capital available to fund its operations; and the

potential benefit of its strategic plans and focus. The words anticipate, expect, hope, milestone, plan, potential, possible, strategy, will,

and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. Such statements are subject to numerous important factors, risks and uncertainties that may

cause actual events or results to differ materially from Agios current expectations and beliefs. For example, there can be no guarantee that any product candidate Agios or its collaborators is developing will successfully commence or complete

necessary preclinical and clinical development phases, or that development of any of Agios product candidates will successfully continue. There can be no guarantee that any positive developments in Agios business will result in stock

price appreciation. Management s expectations and, therefore, any forward-looking statements in

this press release could also be affected by risks and uncertainties relating to a number of other important factors, including: Agios results of clinical trials and preclinical studies,

including subsequent analysis of existing data and new data received from ongoing and future studies; the content and timing of decisions made by regulatory authorities, investigational review boards at clinical trial sites and publication review

bodies; Agios ability to obtain and maintain requisite regulatory approvals and to enroll patients in its planned clinical trials; unplanned cash requirements and expenditures; competitive factors; Agios ability to obtain, maintain and

enforce patent and other intellectual property protection for any product candidates it is developing; Agios ability to maintain key collaborations; and general economic and market conditions. These and other risks are described in greater

detail under the caption Risk Factors included in Agios public filings with the Securities and Exchange Commission. Any forward-looking statements contained in this press release speak only as of the date hereof, and Agios

expressly disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

Condensed Consolidated Balance Sheet Data

Condensed Consolidated Statements of Operations Data

(in thousands, except share and per share data)

Investor & Media Contact:

Holly Manning, 617-844-6630

Associate Director, Investor Relations