Exploring DPX Immunotherapy: Early-Phase Results and Future Prospects in Bladder Cancer

A phase 1 trial showed DPX‑formulated vaccines MVP‑S and DPX‑SurMAGE to be safe and immunogenic in patients with recurrent non‑muscle‑invasive bladder cancer, producing clear tolerability signals and systemic immune activation—findings that support further clinical evaluation.

The two‑arm phase 1 study enrolled 12 patients (9 in the MVP‑S arm, 3 in the DPX‑SurMAGE arm) who had failed intravesical therapy. Investigators administered three subcutaneous injections of the DPX‑formulated constructs, with or without low‑dose cyclophosphamide, and used tolerability and adverse‑event incidence as primary safety endpoints. Treatment was well tolerated with a manageable adverse‑event profile, supporting continued clinical development.

Both DPX constructs induced systemic, antigen‑specific T‑cell responses. MVP‑S typically reached earlier peak responses (around Day 28 in most responders), while DPX‑SurMAGE showed later but robust peaks (about Day 49 in a subset); responses persisted across multiple sampling timepoints.

These results contrast with current NMIBC management, where patients refractory to BCG have limited systemic immunotherapy options and a high unmet need. DPX‑formulated vaccines could function as intravesical adjuncts, systemic options for selected recurrent NMIBC cases, or combination partners with other immune‑modulating agents.

As an early‑phase study with a small sample size and no mature efficacy endpoints, conclusions about clinical benefit remain limited. Next‑phase trials should establish durable clinical responses, optimize dosing and timing, and evaluate the safety and efficacy of combinations with standard intravesical therapies—priorities for forthcoming research and trial planning.

Key Takeaways:

• DPX‑formulated vaccines were safe and elicited systemic T‑cell responses, supporting phase II evaluation.
• Patients with recurrent BCG‑unresponsive NMIBC may be candidates for DPX strategies pending efficacy confirmation.
• Future trials should prioritize randomized efficacy endpoints, optimized dosing schedules, and combinations with intravesical therapy.