DRTS · Alpha Tau Medical Ltd.

This disclosure presents highly material interim clinical data from Alpha Tau’s U.S. REGAIN trial — the company’s first FDA-reviewed study of Alpha DaRT® in recurrent glioblastoma, a disease with median post-recurrence survival under 12 months and no established curative options. The 67% complete response rate (2/3 patients) and 100% local disease control stand in stark contrast to historical objective response rates cited in the filing: 3.4% for biologics, 6.1% for chemotherapies, and 26.8% for antiangiogenics in recurrent GBM — suggesting potentially transformative activity. Critically, these results derive from a prospectively designed, FDA-requested interim safety analysis after only three patients, treated sequentially between December 2025 and March 2026, with data cutoff on May 3, 2026. While the single grade 3 SAE was resolved and no unanticipated SAEs occurred, the small sample size and open-label, single-arm design preclude definitive conclusions on safety or efficacy. The trial’s progression to full enrollment of up to ten patients hinges on FDA confirmation following review of the safety report — making regulatory feedback the next key inflection point. Management explicitly frames these results as validation of their core strategy and rationale to advance into broader brain cancer indications, though the filing reiterates that Alpha DaRT® remains investigational and unapproved in the U.S., and that preliminary data may not predict final outcomes. For investors, this represents a high-potential but high-risk clinical signal — materially de-risking the technology’s biological plausibility in CNS tumors while underscoring dependence on successful trial expansion and future regulatory milestones.