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

Rhea-AI Summary

Cogent Biosciences (Nasdaq: COGT) reported additional SUMMIT trial data for bezuclastinib in NonAdvanced systemic mastocytosis showing durable, deepening benefit through 48 weeks. Key results: mean Total Symptom Score (TSS) change of -32.0 (56% improvement), 99% achieved ≥50% serum tryptase reduction and 83.3% normalization, and clinically meaningful BMD gains at week 24.

The company also disclosed inducement equity grants totaling 24,000 stock options and 21,000 RSUs dated Feb 25, 2026.

Positive

• TSS mean change -32.0 points at 48 weeks (56% improvement)
• 99% of patients achieved ≥50% serum tryptase reduction
• 83.3% of patients achieved serum tryptase normalization
• Clinically meaningful BMD improvements at week 24
• 86% of patients reached ≥30% symptom improvement
• 50% of patients reduced or stopped supportive medications by week 48

Negative

• None.

Key Figures

Mean TSS change: -32.0 points TSS relative improvement: 56% Clinically meaningful TSS responders: 86% of patients +5 more

8 metrics

Mean TSS change -32.0 points SUMMIT NonAdvSM trial at 48 weeks

TSS relative improvement 56% Relative TSS improvement from baseline at 48 weeks

Clinically meaningful TSS responders 86% of patients Patients with ≥30% symptom improvement

Serum tryptase reduction 99% of patients Patients with ≥50% serum tryptase reduction at 48 weeks

Tryptase normalization 83.3% of patients Patients achieving serum tryptase normalization at 48 weeks

Best supportive care reduction 50% of patients Reported dose reduction/discontinuation of best supportive care by week 48

Inducement stock options 24,000 options Nonqualified options granted to new employees on Feb 25, 2026

Inducement RSUs 21,000 RSUs Restricted stock units granted to new employees on Feb 25, 2026

Market Reality Check

Price: $38.89 Vol: Volume 1,556,212 is close...

normal vol

$38.89 Last Close

Volume Volume 1,556,212 is close to the 20-day average of 1,610,103, suggesting no unusual trading activity ahead of this data update. normal

Technical Shares at 38.85 are trading above the 200-day MA of 21.1 and sit below the 52-week high of 43.73 after a large move off the 3.72 52-week low.

Peers on Argus

COGT slipped 1.55% while close peers showed mixed moves, with names like CLDX an...

1 Down

COGT slipped 1.55% while close peers showed mixed moves, with names like CLDX and DYN down and AUPH, IMCR, and MESO up modestly. Only DYN appeared in the momentum scanner, moving down about 3.10%, pointing to stock-specific trading rather than a coordinated biotech sector reaction.

Historical Context

5 past events · Latest: Feb 17 (Positive)

Pattern 5 events

Date	Event	Sentiment	Move	Catalyst
Feb 17	Earnings and pipeline	Positive	+3.0%	Q4 and 2025 results plus multiple NDA milestones for bezuclastinib.
Feb 10	Conference poster preview	Positive	-0.5%	Announcement of multiple SUMMIT posters and prior NDA submission disclosure.
Jan 26	Breakthrough designation	Positive	+3.2%	FDA Breakthrough Therapy Designation for bezuclastinib plus sunitinib in GIST.
Jan 20	RTOR NDA plan	Positive	+2.5%	Plan to submit GIST NDA under Real-Time Oncology Review with strong PEAK data.
Jan 12	2026 milestones outlook	Positive	-1.7%	Outlined 2026 regulatory milestones and commercial launch targets for bezuclastinib.

Pattern Detected

Recent positive clinical and regulatory updates for bezuclastinib often saw modestly positive price reactions, though there are occasional sell-the-news pullbacks on otherwise favorable announcements.

Recent Company History

Over the past months, Cogent has advanced bezuclastinib across multiple indications. A Jan 12, 2026 milestone update outlined planned NDAs in NonAdvSM, GIST, and AdvSM and a potential 2H 2026 launch. Subsequent news highlighted RTOR NDA plans for GIST, Breakthrough Therapy Designation for the GIST combo, and detailed Q4/2025 results with a reported cash balance of $900.8 million. Today’s deeper SUMMIT durability data further extends this NonAdvSM narrative ahead of anticipated regulatory decisions.

Market Pulse Summary

This announcement presents mature 48-week SUMMIT data showing a -32.0-point mean TSS improvement, 86...

Analysis

This announcement presents mature 48-week SUMMIT data showing a -32.0-point mean TSS improvement, 86% of patients reaching clinically meaningful symptom relief, and 99% achieving at least 50% serum tryptase reduction, with 83.3% normalization. These results extend the NonAdvSM story built through recent NDAs and Breakthrough Therapy Designation. Investors may track upcoming regulatory decisions, durability updates, and how inducement equity grants align employee incentives with this evolving bezuclastinib franchise.

Key Terms

nonadvanced systemic mastocytosis, systemic mastocytosis, serum tryptase, bone mineral density, +4 more

8 terms

nonadvanced systemic mastocytosis medical

"pivotal SUMMIT trial with bezuclastinib in patients with NonAdvanced Systemic Mastocytosis"

A rare disorder where certain immune cells called mast cells build up in organs such as the skin, bone marrow or liver, causing symptoms like rashes, flushing, stomach problems and fatigue; “nonadvanced” means the condition is indolent or smoldering rather than rapidly progressing or cancerous. It matters to investors because effective treatments, safety data and regulatory decisions can drive the commercial value and competitive landscape for biotech firms, much like fixing a slow leak prevents a future flood.

systemic mastocytosis medical

"first disease modifying agent for NonAdvSM patient population"

Systemic mastocytosis is a rare disorder in which certain immune cells called mast cells build up in organs such as the skin, bone marrow, liver, and digestive tract, causing recurring allergic-type symptoms, inflammation, and organ damage. For investors, it matters because the condition defines a focused market for diagnostic tests and specialized drugs, influences regulatory designations and pricing power, and can shape the commercial and clinical value of therapies under development — like an overactive alarm system that needs targeted fixes.

serum tryptase medical

"99% of patients achieve >50% reduction in serum tryptase at 48 weeks"

A protein measured in the blood that acts like a smoke detector for cells involved in allergic reactions: higher levels signal activation or increased number of mast cells, which occur during severe allergies, anaphylaxis, or certain blood disorders. Investors care because this lab marker drives demand for diagnostics, informs clinical trial outcomes, and can determine the need or market size for drugs and tests targeting allergic and mast-cell related conditions.

bone mineral density medical

"bezuclastinib’s impact on bone mineral density as additional evidence of disease modification"

A measure of how much mineral — mainly calcium — is packed into a given area of bone, usually obtained from a painless scan; higher values generally mean stronger bones and lower fracture risk. Investors care because changes in this measure are often used as proof that drugs, medical devices, or diagnostics work, so it can drive clinical approval, insurance coverage and sales prospects much like a car’s crash-test rating influences buyer confidence and market demand.

best supportive care medical

"50% of patients reported a dose reduction and/or discontinuation of best supportive care medicines"

Best supportive care is the set of medical treatments and services given to relieve symptoms, manage side effects, and maintain quality of life when a cure is not available or while other treatments are being tested. For investors, it matters because this care often serves as the baseline or comparator in clinical trials and health evaluations, shaping trial results, regulatory decisions, and the perceived added value of new therapies — like comparing a new repair to routine maintenance and comfort measures.

nonqualified options financial

"nonqualified options to purchase 24,000 shares of Cogent common stock"

Nonqualified options are employee stock options that give a holder the right to buy company shares at a set price for a limited period, like a coupon letting you buy a product later at today’s price. They matter to investors because when exercised the difference between market price and the set price is taxed as regular income (affecting the holder’s tax bill) and can dilute existing shares and create a tax deduction for the company.

restricted stock units financial

"and (ii) 21,000 restricted stock units (RSUs)"

Restricted stock units are a type of company reward where employees are promised shares of stock, but they only fully own these shares after meeting certain conditions, like staying with the company for a set time. They matter because they can become valuable assets and are often used to motivate employees to help the company succeed.

nasdaq listing rule 5635(c)(4) regulatory

"approved in accordance with Listing Rule 5635(c)(4) of the corporate governance rules"

NASDAQ Listing Rule 5635(c)(4) is a rule that requires a company to get approval from its shareholders before selling a large amount of its shares, usually over 20%. This helps protect investors by making sure the company doesn't flood the market with new shares without their say, which could lower the stock's value.

AI-generated analysis. Not financial advice.

• 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:
  
  

Symptom/Domain	Mean Change from Baseline	Relative Improvement from Baseline
Dermatologic	-13.94	-65.0%
Neurocognitive	-12.77	-53.6%
Gastrointestinal	-6.63	-62.5%
Pain	-5.43	-45.8%
Fatigue	-3.02	-41.3%

• 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

FAQ

What were Cogent (COGT) SUMMIT trial results for bezuclastinib at 48 weeks?

Bezuclastinib produced a mean -32.0 TSS change at 48 weeks, a 56% relative improvement. According to the company, results also include 99% with ≥50% serum tryptase reduction and 83.3% normalization, with symptom benefit across all domains.

How many Cogent (COGT) patients normalized serum tryptase with bezuclastinib?

About 83.3% of patients achieved serum tryptase normalization by 48 weeks. According to the company, 99% reached ≥50% reduction and the normalization rate was 83.3%, correlating with symptomatic improvements.

Did Cogent (COGT) report bone mineral density benefits with bezuclastinib?

Yes — bezuclastinib showed clinically meaningful BMD improvements at week 24, independent of baseline bone severity. According to the company, these BMD gains are presented as evidence of potential disease modification.

What safety and medication-use effects did Cogent (COGT) note in SUMMIT?

Bezuclastinib demonstrated a favorable tolerability profile supporting chronic use. According to the company, 50% of patients reduced or discontinued supportive medicines by week 48 during treatment.

What inducement equity grants did Cogent (COGT) approve on Feb 25, 2026?

The company approved inducement awards totaling 24,000 nonqualified options and 21,000 RSUs to three new employees. According to the company, options have a 10-year term and standard four-year vesting schedules.