Lytix Biopharma ASA Reports Promising Final Phase II Results for Ruxotemitide (LTX-315) in Combination with Pembrolizumab in PD-1/PD-L1 Refractory Advanced Melanoma

6 patients achieved disease stabilization with several durable responses ongoing at the time of analysis (24 months)

Oslo, Norway, April 21, 2026 – Lytix Biopharma ASA (“Lytix” or the “Company”), a clinical-stage immuno-oncology company developing novel intratumoral cancer therapies, today announced final efficacy and safety results from its Phase II ATLAS-IT-05 study evaluating intratumoral ruxotemitide (LTX-315) in combination with pembrolizumab in patients with advanced melanoma who have progressed following prior checkpoint inhibitor therapy. These data were presented at the American Association for Cancer Research (AACR) Annual Meeting 2026, taking place in San Diego, California.

The open-label, single-arm Phase II study enrolled primarily patients with unresectable stage IIIB to IV metastatic melanoma accessible for intratumoral injection, most of whom were heavily pretreated, with 52.1% having received three or more prior lines of therapy and all having received prior immunotherapy.

Treatment with ruxotemitide in combination with pembrolizumab demonstrated clinically meaningful antitumor activity and a manageable safety profile in this difficult-to-treat population.

Key efficacy findings from the study include: • Objective response rate (ORR): 13.6% among evaluable patients (n=22) • Clinical benefit rate (CBR): 40.9% • Durable responses lasting beyond 24 months in responding patients • Median progression-free survival (PFS): 6.3 months

These outcomes highlight the potential of ruxotemitide to enhance immune responses in patients with PD-1/PD-L1 refractory melanoma, a population with limited therapeutic options.

“The final results from the ATLAS-IT-05 study reinforce our confidence in the ability of ruxotemitide to stimulate anti-tumor immune responses in patients who have progressed after checkpoint inhibitor therapy,” said Øystein Rekdal, Chief Executive Officer of Lytix Biopharma. “Importantly, the durability of responses observed in this heavily pretreated population underscores the potential of our intratumoral approach to generate sustained systemic immunity.”

The safety profile observed in the study was consistent with the known effects of intratumoral immunotherapy and pembrolizumab. The most common treatment-related adverse events were injection-site reactions (95.7%), fatigue (30%), pruritus (26.1%), hypotension (26.1%), and anemia (21.7%). No treatment-emergent adverse events led to discontinuation of pembrolizumab.

About the ATLAS-IT-05 Study ATLAS-IT-05 is a Phase II clinical trial evaluating intratumoral ruxotemitide in combination with pembrolizumab including in patients with advanced melanoma who have progressed following prior anti-PD-1 or anti-PD-L1 therapy (NCT04796194). Patients received up to seven intratumoral injections of ruxotemitide alongside pembrolizumab administered every three weeks until disease progression or for up to 24 months. Key endpoints of the study were objective response rate per RECIST v1.1 criteria, with secondary endpoints including duration of response, progression-free survival, overall survival and safety.

About Ruxotemitide (LTX-315) Ruxotemitide (LTX-315) is a first-in-class oncolytic peptide designed for intratumoral administration. The molecule disrupts tumor cells locally, leading to the release of tumor antigens and danger-associated molecular signals that may activate systemic anti-tumor immune responses. This mechanism has the potential to convert immunologically “cold” tumors into “hot” tumors and enhance responses to checkpoint inhibitor therapies.

About Lytix Biopharma Based in Oslo, Norway, Lytix Biopharma is a clinical-stage biotech company developing a highly differentiated oncolytic molecule platform derived from host-defense peptides. The Company’s lead product, ruxotemitide (formerly LTX-315), represents a novel approach to inducing durable anti-cancer immunity across multiple cancer indications and treatment settings. Lytix is listed on Euronext Growth Oslo under the ticker LYTIX.