Lantern Reports Durable LP-300 Responses in EGFR L858R Lung Cancer

Lantern Pharma has reported updated data from the ongoing Phase 2 HARMONIC trial (NCT05456256) supporting an FDA-cleared protocol amendment that extends LP-300 dosing from six to eight cycles in patients with EGFR Exon 21 L858R-mutant non-small cell lung cancer (NSCLC) following tyrosine kinase inhibitor (TKI) therapy.

As of the May 11, 2026 data cutoff, median progression-free survival (PFS) reached 8.9 months among L858R patients treated through six cycles, compared with 8.4 months across the broader L858R cohort. The findings also showed durable responses, high clinical benefit rates, and a favorable safety profile that supports longer treatment duration.

Mechanistic and Clinical Context

LP-300 is an investigational small molecule with multimodal activity, including receptor tyrosine kinase modulation and redox regulation. The therapy is being developed using insights generated from Lantern Pharma’s RADR® artificial intelligence platform.

Patients with EGFR Exon 21 L858R-mutant NSCLC often experience poorer outcomes after frontline TKI therapy than other EGFR-mutated subgroups. Effective treatment options remain limited once resistance develops, creating a significant unmet need in this molecularly defined population.

Trial Findings

HARMONIC (NCT05456256) is enrolling never-smoker and non-smoker patients with advanced lung adenocarcinoma following prior TKI therapy.

Among evaluable L858R patients, more than 70% achieved tumor shrinkage, including one complete response and multiple partial responses. Select patients maintained responses for more than two years, while the clinical benefit rate reached 77%.

The L858R subgroup demonstrated a hazard ratio of 0.37 for PFS benefit. In exploratory multivariable analyses adjusting for race, gender, and TP53 mutation status, the association remained significant (HR 0.36; 95% CI, 0.15–0.90; p=0.028), further supporting the emerging efficacy signal.

Safety Profile

Safety remained favorable across 31 treated patients, with no clinically meaningful toxicity attributable to LP-300 beyond the carboplatin-pemetrexed backbone. Notably, treatment-related serious adverse events occurred in 3% of LP-300-treated patients, compared with 23% reported for amivantamab plus chemotherapy in the Phase 3 MARIPOSA-2 study, although the trials were not directly comparable.

Rates of treatment discontinuation, infusion reactions, rash, paronychia, and stomatitis also compared favorably with published MARIPOSA-2 results. Investigators noted that the absence of additional toxicity may allow patients to remain on treatment longer and derive greater clinical benefit.

Clinical Implications and Regulatory Outlook

Management highlighted a potential relationship between treatment duration and clinical benefit in the L858R subgroup, where longer exposure to LP-300 appeared to deepen therapeutic benefit without introducing meaningful additional toxicity.

“The tolerability profile of LP-300 allows patients to remain on therapy longer, which is critical to maximizing benefit,” said CEO Panna Sharma. The company noted that these findings provided the rationale for extending treatment duration to eight cycles and increasing focus on the L858R patient population.

The updated findings supported the FDA-cleared protocol amendment extending LP-300 dosing from six to eight cycles. Lantern is now concentrating enrollment on patients with EGFR L858R-mutant disease and is presenting the data during ASCO 2026 while advancing partnering, licensing, and co-development discussions.

The company expects to provide additional updates as the enriched L858R cohort matures and longer-term efficacy and safety data become available.

 Reference

Lantern Pharma Inc – Lantern Pharma Reports HARMONIC™ Data Showing LP-300 Progression-Free Survival Benefit Deepens with Treatment Duration in EGFR Exon 21 L858R Lung Cancer