The market was looking for roughly a 70% three-month complete-response rate. Published pre-readout expectations set a success bar of about 70% three-month CR with relatively clean safety, alongside low-single-digit serious toxicity and no meaningful dose interruptions.
| Measure | SURF302 result | Expectation / context |
|---|---|---|
| 60 mg three-month ORR | 79% (11/14) (Combined Single and Multiple Marker Lesion Response) | — |
| 60 mg three-month CR | 57% (8/14) (Combined Single and Multiple Marker Lesion Response) | ~70% published success bar |
| 50 mg three-month CR | 33% (4/12) (Combined Single and Multiple Marker Lesion Response) | — |
| 60 mg Grade 3 TEAEs | 14% (3/22) (Initial safety and tolerability results) | Low-single-digit severe toxicity expected |
| 60 mg treatment-related discontinuations | 0 (Initial safety and tolerability results) | No meaningful interruptions expected |
Efficacy was encouraging but below the key hurdle. The 60 mg cohort produced a 79% overall response rate, but only 57% achieved a complete response at three months—well short of the approximately 70% CR benchmark. The result is also preliminary: only 14 participants were efficacy-evaluable at 60 mg, and the filing says responses may change with further follow-up. 〔0〕
The safety profile was the clear offset. At 60 mg, there were no dose reductions or treatment-related discontinuations, no Grade 4 or 5 adverse events across either cohort, and no Grade 3 treatment-related adverse events at 60 mg. 〔1〕 This supports chronic dosing, but it does not fully compensate for missing the efficacy bar because the clinical and commercial case depends on durable disease control in the registrational setting.
The 60 mg dose remains usable, but the trial did not establish a clean efficacy win. Best overall CR at 60 mg rose to 64% as one patient converted after the three-month assessment, and all five three-month CRs with six-month assessments remained in response. 〔2〕 That durability signal is positive but based on very few patients, while the company is still completing enrollment and exploring 70 mg for the ablative setting.
Net: mixed clinical read, with safety above expectations but efficacy below the market’s bar. The filing advances 60 mg into planned registrational preparation and adds supportive signals from SURF303 and BEACH301, but the central SURF302 efficacy result is not the clean proof-of-concept investors were primed to see. The next material test is whether larger follow-up cohorts lift complete-response rates and whether regulators accept the proposed Phase 3 design.
Read the original 8-K on SEC EDGAR ↗