• ASP-1929-301, the first Phase 3 randomized controlled trial of ASP-1929, showed median OS of 15.7 months and ORR of 25.8%, with a tolerable safety profile in heavily pretreated recurrent HNSCC
• Real-world multicenter study data of ASP-1929 photoimmunotherapy in recurrent nasopharyngeal cancer showed 86.0% local response and 89.2% two-year survival

Disclaimer: Rakuten Medical’s Alluminox® platform-based photoimmunotherapy is investigational outside Japan.

SAN DIEGO — May 30, 2026 — Rakuten Medical, Inc., a global biotechnology company developing and commercializing Alluminox platform-based photoimmunotherapy, today announced new clinical and real-world data for ASP-1929 photoimmunotherapy (PIT) were presented at the 2026 American Society of Clinical Oncology (ASCO) Annual Meeting in Chicago. 

The first poster presentation reported results from the global Phase 3 ASP-1929-301 study (NCT03769506), a randomized, open-label, controlled trial evaluating ASP-1929 PIT as a monotherapy in patients with locoregional, recurrent head and neck squamous cell carcinoma (HNSCC) who had failed or progressed on or after at least two prior lines of therapy and were not eligible for surgery or radiation. 

A second poster presentation updated outcomes from an investigator-initiated nationwide, multicenter, real‑world study (UMIN000060367) of ASP‑1929 PIT in recurrent nasopharyngeal cancer (NPC) in Japan.

“Head and neck cancer is the seventh most common cancer worldwide, with nearly one million new cases and about half a million deaths each year. Despite treatment, 20% to 30% of patients experience recurrence,” said Anastasios Maniakas, M.D., Ph.D., assistant professor of Head and Neck Surgery at The University of Texas MD Anderson Cancer Center. “In our study, ASP-1929 photoimmunotherapy saw encouraging tumor response, durable local control, and a manageable safety profile. These findings support continued clinical evaluation.” 

Rakuten Medical is currently conducting the global Phase 3 ASP-1929-381 study (NCT06699212) evaluating ASP-1929 PIT in combination with pembrolizumab as a first-line treatment for locoregional recurrent HNSCC in the United States, Taiwan, Japan and Ukraine. 

Details of the two poster presentations are as follows:

Poster Presentation for Global Phase 3 ASP-1929-301 Study:

• Title: A phase 3, randomized, double-arm, open-label, controlled study of ASP-1929 photoimmunotherapy (PIT) versus physician’s choice standard of care (SOC) for patients with locoregional, recurrent head and neck squamous cell carcinoma (HNSCC)
• Poster: View/Download Poster [PDF]
• Poster Presentation Recording: Watch the Video 
• Key Findings (Data cutoff: April 30, 2025): 
  • 135 patients were randomized (ASP-1929 PIT: 89; SOC: 46), with approximately two-thirds having received ≥3 prior lines of therapy
  • Interpretation is limited by smaller sample size and higher dropout in the SOC arm (28.3% vs. 5.6% in the ASP-1929 PIT arm)
  • Efficacy (PIT vs. SOC):
    • Progression-free survival (PFS), a primary endpoint, was similar between treatment arms (Median 3.2 vs. 3.1 months; Hazard Ratio (HR) 0.98)
    • Overall Survival (OS), another primary endpoint, showed a longer numerical trend with ASP-1929 PIT (Median 15.7 vs. 9.6 months; HR 0.83)
    • Objective Response Rate (ORR) and Disease Control Rate (DCR), key secondary endpoints, were numerically higher with ASP-1929 PIT (25.8% vs. 15.2% and 68.5% vs. 43.5%, respectively)
  • Safety (PIT vs. SOC):
    • Grade ≥3 treatment-emergent adverse events (TEAEs) were more frequent with ASP-1929 PIT (58.3% vs. 36.4%); however, fewer TEAEs led to dose modification, delay, interruption (15.5% vs. 30.3%) or discontinuation (4.8% vs. 9.1%)
    • Adverse events in the ASP-1929 PIT arm were primarily driven by localized and inflammatory reactions, most of which were low grade and clinically manageable
  • Quality of Life (QoL):
    • No overall negative impact on QoL was observed in the ASP-1929 PIT arm compared with SOC
    • ECOG performance status improved in 19.1% of patients in the ASP-1929 PIT arm vs. 0% in the SOC arm

Poster Presentation for Real‑World Japanese Multicenter Data for Recurrent NPC:

• Title: Real-world efficacy and safety of photoimmunotherapy for recurrent nasopharyngeal carcinoma: A nationwide multicenter study in Japan
• Poster: View/Download Poster [PDF]
• Key Findings: 
  • Efficacy:
    • Among 43 evaluable patients, 31 (72.1%) achieved a local CR lasting ≥2 months
    • Including 6 (14.0%) PR, the overall local response rate was 86.0% (37/43)
    • More than half of the patients (22/43, 51.2%) remained alive with no evidence of disease at the time of last follow-up
    • The 2-year OS was 89.2%
  • Safety:
    • Grade ≥3 TEAEs were observed in 10 patients (23%), while Grade ≥3 treatment-related adverse events (TRAEs) were observed in 7 patients (16%)
    • Osteomyelitis and mucositis were the most common Grade ≥3 adverse events, highlighting the importance of careful local infection control
    • Two fatal carotid hemorrhages occurred, possibly in association with underlying osteomyelitis