Rakuten Medical announces promising interim results from photoimmunotherapy study at ASCO 2024

Rakuten Medical, Inc., a pioneer in biotechnology focusing on precision, cell-targeting photoimmunotherapy, unveiled updated interim results from its Phase 1b/2 study of ASP-1929 photoimmunotherapy in combination with anti-PD-1 therapy. The data, presented at the 2024 American Society of Clinical Oncology Annual Meeting (ASCO 2024) on June 2, 2024, provides new insights into the treatment of recurrent and/or metastatic head and neck squamous cell carcinoma (HNSCC).

Interim Findings Highlight Treatment Potential

The study, known as ASP-1929-181 and registered under ClinicalTrials.gov Identifier NCT04305795, involved 19 patients and revealed promising early outcomes. With a median overall survival (OS) not yet reached at the data cut-off of August 31, 2023, the estimated survival rate stood at 52.4% at 24 months. The objective response rate (ORR) was recorded at 35.3%, which includes both complete and partial responses.

Clinical Responses and Safety Profile

Patients treated with the combination of ASP-1929 and anti-PD-1 showed significant clinical activity:

– Median time to response was remarkably quick at 1.4 months.

– Median progression-free survival (PFS) was calculated at 2.9 months.

Adverse events were predominantly manageable and did not lead to any synergistic serious adverse events (SAEs), underlining the treatment’s tolerability. The study reported two Grade 4 SAEs, one related to photoimmunotherapy and the other unrelated to the treatment, both of which were resolved.

Advancing to Phase 3 Trials

Encouraged by these interim results, Rakuten Medical completed a Type B End-of-Phase 2 (EOP2) meeting with the U.S. Food and Drug Administration (FDA) to discuss launching a multi-regional registrational study. The planned global phase 3 clinical trial is set to begin in the second half of 2024, with a primary endpoint focused on OS.

Future Directions and Impact

These interim findings are provisional and subject to change upon the completion of follow-up and final data analysis. However, the promising results thus far warrant further exploration to validate the efficacy and safety of ASP-1929 in combination with anti-PD-1 therapy in a broader patient population.