Syndax Pharmaceuticals, Inc.

Syndax Pharmaceuticals Reports First Quarter 2017 Financial Results and Provides Clinical and Business Update

Enrollment of second stage of melanoma cohort in Phase 2 ENCORE 601 trial proceeding ahead of schedule; expected to be completed in the third quarter

Company to host conference call today at 4:30 p.m. ET

WALTHAM, Mass., May 08, 2017 (GLOBE NEWSWIRE) -- Syndax Pharmaceuticals, Inc. ("Syndax," the "Company" or "we") (Nasdaq:SNDX), a clinical stage biopharmaceutical company developing entinostat and SNDX-6352 in multiple cancer indications, today reported its financial results for the first quarter ended March 31, 2017. In addition, the Company provided a clinical and business update. As of March 31, 2017, Syndax had $92.8 million in cash, cash equivalents and short-term investments.

During the first quarter, the Company continued to advance its ENCORE immuno-oncology clinical programs. The Company reported that enrollment in the second stage of the melanoma cohort in ENCORE 601 is proceeding ahead of schedule, with completion of enrollment expected by the end of the third quarter of 2017. Results for the melanoma cohort from the first stage of ENCORE 601 will be presented at the American Society of Clinical Oncology (ASCO) Annual Meeting in June.

The Company also recently announced the expansion of ENCORE 601, a Phase 2 clinical collaboration with a subsidiary of Merck, known as MSD outside the United States and Canada, to include a cohort of patients with microsatellite stable colorectal cancer who have not previously been treated with an anti-PD-1 (programmed death receptor-1) therapy. These cancers represent about 85% of all colon cancers and have shown minimal response to anti-PD-1 therapy. The expansion was based in part on clinical responses observed in the PD-1 refractory melanoma cohort of ENCORE 601. Enrollment is expected to begin mid-2017.

"Our pipeline of innovative therapeutic candidates for cancer continues to make meaningful progress, and the recent melanoma results, as well as the expansion of ENCORE 601 into colorectal cancer, highlight the potential application of entinostat to a broad range of cancers. We believe the substantial unmet medical need in melanoma patients who have failed treatment with a PD-1 antagonist represents a fast to market opportunity for an effective and well tolerated therapy, and we look forward to presenting updated results from the melanoma cohort of ENCORE 601 at ASCO. In addition, we have secured a Type B meeting with the FDA in late June to discuss the development path for entinostat in melanoma," said Briggs W. Morrison, M.D., Chief Executive Officer of Syndax. "Later this quarter, we anticipate determining whether either of the non-small cell lung cancer cohorts have met the prespecified criteria to advance to the second stage of the trial."

"Based on updates from the Eastern Cooperative Oncology Group regarding enrollment in the ongoing E2112 Phase 3 registration trial, completion of enrollment and progression free survival analysis are anticipated in the first half of 2018. This trial of entinostat plus exemestane in advanced HR+, HER2- breast cancer is being conducted with ECOG-ACRIN and the National Cancer Institute under a Special Protocol Assessment with the FDA," said Michael L. Meyers, M.D., Ph.D., Chief Medical Officer of Syndax.

Pipeline Updates

Syndax Expects to Participate in the Following Upcoming Investor Conferences

First Quarter 2017 Financial Results

As of March 31, 2017, Syndax had cash, cash equivalents and short-term investments of $92.8 million and 18,244,917 shares issued and outstanding.

First quarter 2017 research and development expenses increased to $9.6 million from $4.8 million for the comparable period in the prior year. The increase was primarily due to increased clinical trial activities of $3.4 million, employee compensation expense of $0.8 million, legal and consultant expenses of $0.5 million and facility costs of $0.1 million.

General and administrative expenses totaled $3.9 million during the first quarter of 2017 compared with $4.3 million in the comparable period in the prior year. The decrease in general and administrative expenses was primarily due to a decrease in employee compensation of $0.7 million partially offset by increases in consulting expenses and other costs related to being a public company of $0.3 million. The decrease in employee compensation of $0.7 million was primarily due to decreases in non-cash stock-based compensation of $0.9 million and bonus expense of $0.2 million, partially offset by an increased salary expense of $0.3 million due to increased headcount.

For the three months ended March 31, 2017, Syndax reported a net loss attributable to common stockholders of $13.0 million, or $0.71 per share, compared to $12.9 million, or $2.85 per share, for the comparable prior year period.

Financial Guidance

Today the Company provided operating expense guidance for the second quarter and full year 2017. For the second quarter and full year 2017, research and development expenses are expected to be $11.0 — $13.0 million and $52.0 - $57.0 million, respectively, and total operating expenses are expected to be $15.0 — $17.0 million and $68.0 - $73.0, respectively.

Conference Call and Webcast

In connection with the earnings release, Syndax's management team will host a conference call and live audio webcast at 4:30 p.m. ET today, Monday, May 8, 2017.

The live audio webcast and accompanying slides may be accessed through the Events & Presentations page in the Investors section of the Company's website at Alternatively, the conference call may be accessed through the following:

Conference ID: 8354328
Domestic Dial-in Number: 1-855-251-6663
International Dial-in Number: 281-542-4259
Live webcast:

For those unable to participate in the conference call or webcast, a replay will be available for 30 days on the Investors section of the Company's website,

About Syndax Pharmaceuticals, Inc.

Syndax is a clinical stage biopharmaceutical company developing an innovative pipeline of cancer therapies. Our lead product candidate, entinostat, which was granted Breakthrough Therapy designation by the FDA following positive results from our Phase 2b clinical trial, ENCORE 301, is currently being evaluated in a Phase 3 clinical trial for advanced hormone receptor positive, human epidermal growth factor receptor 2 negative breast cancer. Given its potential ability to block the function of immune suppressive cells in the tumor microenvironment, entinostat is also being evaluated in combination with approved PD-1 antagonists. Ongoing Phase 1b/2 clinical trials combine entinostat with KEYTRUDA® from Merck & Co., Inc. for non-small cell lung cancer and melanoma; with TECENTRIQ® from Genentech, Inc. for TNBC; and with BAVENCIOTM from Pfizer Inc. and Merck KGaA, Darmstadt, Germany, for ovarian cancer. Our second product candidate, SNDX-6352, is a monoclonal antibody that blocks the CSF-1 receptor and may also block the function of immune suppressive cells in the tumor microenvironment. SNDX-6352 is being evaluated in a single ascending dose Phase 1 clinical trial and is expected to be developed to treat a variety of cancers.

Syndax's Cautionary Note on Forward-Looking Statements

This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as "may," "will," "expect," "plan," "anticipate," "estimate," "intend," "believe" and similar expressions (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. These forward-looking statements are based on Syndax's expectations and assumptions as of the date of this press release. Each of these forward-looking statements involves risks and uncertainties. Actual results may differ materially from these forward-looking statements. Forward-looking statements contained in this press release include, but are not limited to, statements about the progress, timing, clinical development and scope of clinical trials and the reporting of clinical data for Syndax's product candidates, and the potential use of our product candidates to treat various cancer indications. Many factors may cause differences between current expectations and actual results including unexpected safety or efficacy data observed during preclinical or clinical studies, clinical trial site activation or enrollment rates that are lower than expected, changes in expected or existing competition, changes in the regulatory environment, failure of Syndax's collaborators to support or advance collaborations or product candidates and unexpected litigation or other disputes. Other factors that may cause Syndax's actual results to differ from those expressed or implied in the forward-looking statements in this press release are discussed in Syndax's filings with the U.S. Securities and Exchange Commission, including the "Risk Factors" sections contained therein. Except as required by law, Syndax assumes no obligation to update any forward-looking statements contained herein to reflect any change in expectations, even as new information becomes available.

(In thousands)March 31, 2017 December 31, 2016 
Cash, cash equivalents, and short-term investments$  92,785  $  105,330  
Other assets    4,882     3,683  
Total assets$  97,667  $  109,013  
Current liabilities$  10,989  $  10,366  
Deferred revenue, less current portion   13,915     14,220  
Other liabilities   148     288  
Total liabilities   25,052     24,874  
Total stockholders' equity    72,615     84,139  
Total liabilities and stockholders' equity$  97,667  $  109,013  
   Three Months Ended March 31, 
(In thousands, except share and per share data) 2017   2016  
License fee revenue$  305  $  305  
Operating expenses:    
 Research and development   9,552     4,786  
 General and administrative   3,930     4,272  
Total operating expenses   13,482     9,058  
Loss from operations   (13,177)    (8,753) 
Other income (expense), net   206     (1,577) 
Net loss $  (12,971) $  (10,330) 
Net loss attributable to common stockholders$  (12,971) $  (12,928) 
Net loss per share attributable to common    
 stockholders--basic and diluted$  (0.71) $  (2.85) 
Weighted-average number of common stock    
 used to compute net loss per share attributable     
 to common stockholders--basic and diluted   18,231,602     4,541,536  
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