CAMBRIDGE, Mass., Nov. 18, 2020 /PRNewswire/ -- Cogent Biosciences, Inc. (Nasdaq: COGT), a biotechnology company focused on developing precision therapies for genetically defined diseases, today announced the final results from its PLX9486 + sunitinib Phase 1/2 study in patients with advanced gastrointestinal stromal tumors (GIST). The data will be presented, summarized and discussed in a live oral session on Friday, November 20th from 11:30 a.m. to 12:30 p.m. ET at the Connective Tissue Oncology Society (CTOS) 2020 virtual meeting.
PLX9486 is a selective tyrosine kinase inhibitor designed to potently inhibit KIT exon 17 mutations, including D816V. Most patients with imatinib-resistant GIST have both primary and secondary KIT mutations, often including secondary mutations on exon 17 and exon 13, making it difficult to achieve broad therapeutic KIT inhibition. These data suggest that treatment with a combination of PLX9486, a type 1 KIT inhibitor with activity against exon 17 mutations, and sunitinib, a type 2 KIT inhibitor with activity against exon 13 mutations, may provide substantial clinical benefit over treatment with type I or type II inhibitors alone.
"We are pleased to share final results from our Phase 1/2 trial of PLX9486 + sunitinib and are excited to advance this combination into a Phase 3 GIST trial in the second half of 2021," said Andrew Robbins, President and CEO of Cogent Biosciences. "With a median progression free survival (PFS) of 12 months in a heavily pre-treated population of advanced GIST patients, this combination holds significant promise for these patients with unmet medical need."
Title: The potent and selective kit inhibitor PLX9486 dosed in combination with sunitinib demonstrates promising progression free survival (PFS) in patients with advanced gastrointestinal stromal tumor (GIST): final results of a phase 1/2 study.
Date: November 20, 2020
Time: Session 8: 11:30 a.m. - 12:30 p.m. ET
"The final results from this Phase 1/2 trial are highly encouraging for GIST patients who have limited treatment options due to secondary resistance KIT mutations," said Jonathan Trent, M.D., Ph.D., Associate Director for Clinical Research, Sylvester Comprehensive Cancer Center, University of Miami Health System. "I look forward to participating in the upcoming trial of this promising combination for imatinib-resistant GIST patients."
Out of the 18 patients with advanced GIST enrolled in the trial, all patients had received prior treatment, including 67% of patients with at least three prior lines of therapy. Doses for this study included 3 levels:
- Level 1: PLX9486 500mg + sunitinib 25mg (3 patients)
- Level 2: PLX9486 1000mg + sunitinib 25mg (5 patients)
- Level 3: PLX9486 1000mg + sunitinib 37.5mg (10 patients)
Among the 15 patients who had not previously received PLX9486 as a single agent, the median progression free survival (PFS) was 12 months, the confirmed ORR was 20% and the clinical benefit rate (CR+PR+SD) was 80%, with 27% of patients remaining on therapy out 27-34 months. Importantly, there were no dose limiting toxicities in the three dose levels tested, and the most common adverse events were anemia, hypophosphatemia, diarrhea, and lymphopenia.
About Cogent Biosciences, Inc.
Cogent Biosciences is a biotechnology company focused on developing precision therapies for genetically defined diseases. The most advanced clinical program, PLX9486, 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. Cogent Biosciences is headquartered in Cambridge, MA. Visit our website for more information at www.cogentbio.com. Follow Cogent Biosciences on social media: Twitter and LinkedIn.
Forward Looking Statements
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SOURCE Cogent Biosciences, Inc.