Black Diamond Therapeutics, Inc. 8-K

What Happened
On May 21, 2026, Black Diamond Therapeutics (BDTX) announced positive interim Phase 2 results for silevertinib in frontline (1L) non‑small cell lung cancer (NSCLC) patients with EGFR non‑classical mutations (EGFR‑NCMs). The trial enrolled 43 patients (all dosed at 200 mg QD) and, with an April 11, 2026 data cutoff and median follow‑up of 11.2 months, reported a preliminary median progression‑free survival (PFS) of 15.2 months (95% CI: 10.8, NE). Median duration of response (DOR) was not reached (95% CI: 7.0, NE). Reported objective response rate (ORR) by RECIST 1.1 was 60% and disease control rate (DCR) was 91%. CNS activity remained high (RANO‑BM ORR 86%); no patients developed new (de novo) brain metastases.

Key Details

• Trial/population: 43 frontline NSCLC patients with diverse EGFR‑NCMs, including PACC and compound mutations; 19 had brain metastases (7 with measurable CNS lesions).
• Efficacy: Preliminary median PFS 15.2 months; ORR 60% (RECIST 1.1); DCR 91%; CNS ORR 86% (RANO‑BM).
• Durability/ongoing: Median follow‑up 11.2 months; 23 of 43 patients (53%) remain on therapy; longest on treatment = 23.5 months.
• Safety/dosing: No new safety signals; rate of treatment‑related adverse events > Grade 3 fell to 28% after dose reductions. Patients often maintained or deepened responses after dose reduction; company supports 150 mg QD for pivotal development.
• Biomarker: Variant allele frequency reductions seen in all evaluable patients across 25 unique EGFR‑NCMs (including PACC).
• Filing: Results were disclosed in a press release furnished as Exhibit 99.1 to the 8‑K filed May 21, 2026; the study is ongoing.

Why It Matters
For investors, these data suggest silevertinib has meaningful activity and durability in a difficult‑to‑treat subset of newly diagnosed NSCLC patients with non‑classical EGFR mutations, including patients with brain metastases. The safety profile after dose adjustment and the company’s selection of 150 mg QD for pivotal development are material because they affect the design and feasibility of late‑stage trials and potential regulatory paths. The study is interim and ongoing, and BDTX’s statements are forward‑looking and subject to risks described in its SEC filings.