Lantern Pharma Inc. (NASDAQ: LTRN) reported clinical data from its Phase 2 HARMONIC trial showing that patients with EGFR Exon 21 L858R-mutant non-small cell lung cancer who received up to six cycles of LP-300 treatment achieved a median progression-free survival of 8.9 months.

The trial evaluated LP-300 in combination with carboplatin and pemetrexed in patients whose cancer had progressed following tyrosine kinase inhibitor therapy. The overall L858R patient group (n=15) showed a median progression-free survival of 8.4 months, according to data with a cutoff date of May 11, 2026.

More than 70% of evaluable L858R patients experienced tumor reduction, with some responses lasting beyond two years. The L858R cohort demonstrated a 77% clinical benefit rate. The company reported a hazard ratio of 0.37 (95% CI 0.15–0.89) for the L858R subgroup.

The treatment showed what the company described as a clean safety profile, with LP-300 adding no clinically meaningful toxicity beyond the standard chemotherapy backbone. Among 31 patients treated with LP-300 plus chemotherapy, 3% experienced treatment-related serious adverse events.

The FDA has cleared a protocol amendment allowing patients to receive up to eight cycles of LP-300, extended from the previous maximum of six cycles. The company said this decision was based on observations that progression-free survival benefit appeared to deepen with longer treatment duration.

Lantern Pharma filed the presentation data as an exhibit to a Form 8-K and is using the information for partnering discussions during the American Society of Clinical Oncology meeting in Chicago.