Black Diamond Therapeutics (BDTX) Study result summary

Study background and patient population

• Phase II trial enrolled 43 treatment-naive non-small cell lung cancer patients with EGFR non-classical mutations, including PACC and compound mutations, at a 200 mg silevertinib daily dose.

• 44% had baseline brain metastases, and 33 unique NCMs were represented; 19 had brain metastases, 7 with measurable CNS lesions.

• Median follow-up was 11.2 months as of the April 11, 2026 data cutoff.

Efficacy and clinical outcomes

• Confirmed objective response rate was 60% and disease control rate was 91%, with responses across all mutation subclasses including PACC.

• CNS response rate was 86% among patients with measurable brain metastases, and no patients developed de novo brain metastases during the study.

• Preliminary median progression-free survival was 15.2 months, a 40% improvement over historical benchmarks.

• 53% of patients remained on therapy at data cutoff, with the longest duration at 23.5 months.

• Variant allele frequency reduction was observed in all evaluable patients across 25 unique EGFR-NCMs.

Safety and tolerability

• Most common adverse events were rash, diarrhea, paronychia, and stomatitis, consistent with other EGFR TKIs.

• Dose reductions to 150 mg or 100 mg were common, reducing Grade 3 or higher adverse events to 28–30%.

• Dose reduction did not compromise efficacy; patients maintained or deepened responses.

• No new safety signals were observed; adverse events were dose-dependent and manageable.

• Six patients discontinued due to adverse events, a small proportion overall.