Cogent Biosciences Highlights Additional Data with Six Bezuclastinib Posters from SUMMIT Trial at 2026 AAAAI Annual Meeting

• Bezuclastinib mean TSS reduction deepens to –32.0 points at 48 weeks of treatment with further improvement shown across all measured symptoms
  
• 99% of patients achieve >50% reduction in serum tryptase at 48 weeks, with 83% rate of normalization
  
• Strong evidence of bezuclastinib’s potential as first disease modifying agent for NonAdvSM patient population given clear correlation between objective measures of disease burden and symptomatic improvement
  

WALTHAM, Mass. and BOULDER, Colo., Feb. 28, 2026 (GLOBE NEWSWIRE) -- Cogent Biosciences, Inc. (Nasdaq: COGT), a biotechnology company focused on developing precision therapies for genetically defined diseases, today announced additional clinical results from the pivotal SUMMIT trial with bezuclastinib in patients with NonAdvanced Systemic Mastocytosis (NonAdvSM) at the American Academy of Allergy Asthma & Immunology (AAAAI) Annual Meeting. As previously reported, bezuclastinib demonstrated clinically meaningful and highly statistically significant improvements across the primary and all key secondary endpoints. New results highlight the deepening of clinical benefit over longer treatment duration, the benefit of bezuclastinib in populations with high unmet need, and bezuclastinib’s impact on bone mineral density as additional evidence of disease modification.

“The additional SUMMIT data presented at AAAAI today reinforce our belief that bezuclastinib can rapidly and meaningfully improve a wide variety of symptoms that impact the daily lives of patients with NonAdvanced SM,” said Andrew Robbins, Cogent’s President and Chief Executive Officer. “These posters underscore the significance of our findings and build upon the data we shared at ASH last year. Adding
all these results together, bezuclastinib’s profile continues to be a very active, well-tolerated option for NonAdvSM patients, which we believe has the opportunity to become the preferred standard of care.”

Data Highlights from the SUMMIT Posters

• Treatment with bezuclastinib resulted in rapid, durable, statistically significant symptomatic improvements which continued to deepen out to 48 weeks:
  
  
• • Patients on bezuclastinib reported a -32.0 point mean change in TSS, representing a 56% relative improvement in TSS from baseline
  • 86% of patients achieved a clinically meaningful threshold of 30% improvement in symptoms
  • 99% of patients had at least 50% reduction in serum tryptase, with 83.3% of patients achieving normalization
    
• Patients treated with bezuclastinib reported clear improvements across all relevant organ systems as evidenced by relative improvement at 48 weeks:
  

• Bezuclastinib demonstrates strong evidence of disease modification in NonAdvSM patients based on:
  
  
• • Significant correlation shown between serum tryptase reduction and symptomatic improvement as measured by TSS (primary endpoint), all symptom domains, and 10/11 individual symptoms
  • Clinically meaningful improvements in bone mineral density (BMD) at week 24 for patients treated with bezuclastinib, regardless of baseline bone health severity.
  • 50% of patients reported a dose reduction and/or discontinuation of best supportive care medicines during the treatment period at week 48
    
• Bezuclastinib demonstrates consistent biomarker and symptomatic improvement in patients with smoldering SM, a subgroup of NonAdvSM with high unmet need.
  

As previously reported, bezuclastinib demonstrated a favorable safety and tolerability profile, supporting its potential for chronic use in patients with NonAdvSM. 

Copies of Cogent’s data presentations from the AAAAI Annual Meeting will be available in the Posters and Publications section of the company’s website at cogentbio.com.

Inducement Grants Under Nasdaq Listing Rule 5635(c)(4)
Cogent also announced today that, on February 25, 2026, the Compensation Committee of Cogent’s Board of Directors, made up entirely of independent directors, approved the grants of “inducement” equity awards to three new employees under the company’s 2020 Inducement Plan with a grant date of February 25, 2026. The awards were approved in accordance with Listing Rule 5635(c)(4) of the corporate governance rules of the Nasdaq Stock Market. The employees received, in the aggregate, (i) nonqualified options to purchase 24,000 shares of Cogent common stock and (ii) 21,000 restricted stock units (RSUs). Each option has a 10-year term, an exercise price equal to the closing price of Cogent’s common stock on the grant date, and a 4-year vesting schedule with 25% vesting on the 1-year anniversary of the grant date and the remainder vesting in equal monthly installments over the subsequent 36 months, provided such employee remains employed through each such vesting date. The RSUs vest annually in equal installments over 4 years from the grant date, provided such employee remains employed through each such vesting date.      

About Cogent Biosciences, Inc.
Cogent Biosciences is a biotechnology company focused on developing precision therapies for genetically defined diseases. The most advanced clinical program, bezuclastinib, is a selective tyrosine kinase inhibitor that is designed to potently inhibit the KIT D816V mutation as well as other mutations in KIT exon 17. KIT D816V is responsible for driving systemic mastocytosis, a serious disease caused by unchecked proliferation of mast cells. Exon 17 mutations are also found in patients with advanced gastrointestinal stromal tumors (GIST), a type of cancer with strong dependence on oncogenic KIT signaling. The company also has an ongoing Phase 1 study of its novel internally discovered FGFR2/3 inhibitor. In addition, the Cogent Research Team is developing a portfolio of novel targeted therapies to help patients fighting serious, genetically driven diseases targeting mutations in ErbB2, PI3Kα, KRAS and JAK2. Cogent Biosciences is based in Waltham, MA and Boulder, CO. Visit our website for more information at www.cogentbio.com. Follow Cogent Biosciences on social media: X (formerly known as Twitter) and LinkedIn. Information that may be important to investors will be routinely posted on our website and X.

Forward Looking Statements
This press release contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including, but not limited to, statements regarding: bezuclastinib’s potential to be the first disease modifying agent for patients with NonAdvSM; the company’s belief that bezuclastinib can rapidly and meaningfully improve a wide variety of symptoms that impact the daily lives of patients with NonAdvSM; the company’s belief that bezuclastinib has the opportunity to become the preferred standard of care for patients with NonAdvSM; and the potential for bezuclastinib’s chronic use in patients with NonAdvSM. The use of words such as, but not limited to, "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "might," "plan," "potential," "predict," "project," "should," "target," "will," or "would" and similar words expressions are intended to identify forward-looking statements. Forward-looking statements are neither historical facts nor assurances of future performance. Instead, they are based on our current beliefs, expectations and assumptions regarding the future of our business, future plans and strategies, our clinical results, the rate of enrollment in our clinical trials and other future conditions. New risks and uncertainties may emerge from time to time, and it is not possible to predict all risks and uncertainties. No representations or warranties (expressed or implied) are made about the accuracy of any such forward-looking statements. We may not actually achieve the forecasts or milestones disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Such forward-looking statements are subject to a number of material risks and uncertainties including but not limited to those set forth under the caption "Risk Factors" in Cogent's most recent Quarterly Report on Form 10-Q filed with the SEC. Any forward-looking statement speaks only as of the date on which it was made. Neither we, nor our affiliates, advisors or representatives, undertake any obligation to publicly update or revise any forward-looking statement, whether as result of new information, future events or otherwise, except as required by law. These forward-looking statements should not be relied upon as representing our views as of any date subsequent to the date hereof.

Contact:
Christi Waarich
Senior Director, Investor Relations
christi.waarich@cogentbio.com
617-830-1653