Cogent Biosciences Prepares Up to Three FDA Filings for Bezuclastinib Following Pivotal Wins

Cogent Biosciences is preparing parallel new drug application submissions to the U.S. Food and Drug Administration for bezuclastinib across three indications following positive pivotal trial results in the second half of 2025. The company expects to launch in "somewhere between one and all three" indications by the end of 2026 depending on FDA review outcomes, with full commercialization in all three indications expected by early 2027.

Bezuclastinib is being developed across three patient populations: non-advanced systemic mastocytosis, advanced systemic mastocytosis, and gastrointestinal stromal tumors (GIST). Pivotal studies in each of these settings "read out positively" in the second half of 2025. Cogent submitted a New Drug Application for bezuclastinib in non-advanced systemic mastocytosis with acceptance expected in March 2026. The company plans to submit an NDA for second-line gastrointestinal stromal tumors in April and an advanced systemic mastocytosis NDA in the first half of 2026. The drug is positioned for potential approval and launch in the second half of 2026. Timing of commercial launch will depend on FDA review timelines.

Cogent estimates there are roughly 30,000 non-advanced systemic mastocytosis patients in the U.S., though not all are diagnosed. The company estimates 6,000 to 8,000 patients in the U.S. have moderate-to-severe symptoms that could lead to chronic therapy use, with a "corresponding number" in Europe. Using pricing assumptions based on AYVAKIT's U.S. wholesale acquisition cost of about $43,000 per month (and lower pricing in Europe), the total available market could be approximately $3.5 billion to $4 billion, primarily across the U.S. and Western Europe.

The SUMMIT trial enrolled patients across indolent, smoldering, and bone marrow mastocytosis, which contrasts with the PIONEER trial for avapritinib (AYVAKIT), which enrolled indolent patients only. Bezuclastinib's potential differentiation is attributed to selectivity and lack of central nervous system (CNS) penetration. Avapritinib is characterized as "highly CNS-penetrant" and a multi-kinase inhibitor that also hits PDGFR and, to a lesser extent, CSF1R and FLT3. By contrast, bezuclastinib is non-CNS penetrant and highly selective for KIT, allowing higher exposure levels and a better therapeutic index in this mutation-driven disease.

Cogent presented one-year data showing a 32-point average symptom improvement on a 0-to-110 symptom scale, compared with about 17 points for avapritinib patients after four years based on recent presented data. About 99% of patients in Cogent's presented data achieved a 50% or greater serum tryptase reduction, compared with about 50% of avapritinib-treated patients. A presentation showed that about one-third of patients at six months had bone marrow biopsies with "no evidence of disease."

In GIST, the PEAK combination with sunitinib showed a median progression-free survival of 16.5 months and an objective response rate near 50%. Cogent received Breakthrough Therapy Designation from the U.S. Food and Drug Administration for its bezuclastinib treatment in combination with sunitinib based on the PEAK trial results. This designation aims to expedite the review process for therapies that show potential for significant improvement over existing treatments.

Across more than 800 patients treated in APEX, SUMMIT, and PEAK, Cogent has not observed "serious liver clinical consequences," characterizing liver-related events as lab abnormalities that returned to baseline with continued dosing, dose reductions, or, rarely, discontinuation. The company expects possible label language around monitoring early in treatment but does not expect a boxed warning or Risk Evaluation and Mitigation Strategy (REMS). Data from avapritinib's PATHFINDER study in advanced systemic mastocytosis at 200 mg described intracranial hemorrhage findings, an 80% incidence of edema, and cognitive impairment observed in more than 40% of patients at that dose.

CMC is ready, expanded access programs are active, and Cogent has begun building a commercial team with approximately 40 hires ahead of launch. Cogent is also advancing its pipeline with clinical data expected in 2026 for FGFR2/3 inhibitor CGT4859 and dose escalation completion for selective ErbB2 inhibitor CGT4255 and PI3Kα inhibitor CGT6297.

The company's stock price currently stands at $37.62, having delivered a 364% return over the past year. Cogent currently carries a market capitalization of $5.72 billion.