Introduction: BLP25 liposome vaccine (L-BLP25) is an innovative therapeutic cancer vaccine designed to induce an immune response resulting in elimination of tumor cells expressing the MUC1 antigen, which is overexpressed in non-small-cell lung cancer (NSCLC). Manufacturing modifications have produced subtle changes to the lipid A acyl chain composition of L-BLP25. This open-label phase II study was conducted to evaluate the safety of the new formulation in patients with unresectable stage IIIA/IIIB NSCLC.
Patients and methods: Twenty-two patients received L-BLP25 1000 µg every week for 8 weeks plus best supportive care. Maintenance vaccinations were given every 6 weeks, commencing at week 13, until disease progression.
Results: Median treatment duration was 9.9 months (range, 1-30 months), 9 patients remain on treatment, and 8 have received treatment for > 2 years. Fifteen patients (68%) had adverse events considered to be related to L-BLP25: these were all grade 1/2, except for 1 grade 3 event (pneumonia). The most common adverse events were injection-site reactions (bruising [23%], erythema [18%], pain [14%], fatigue [18%], and influenza-like illness [14%]). After a median follow-up of 26.7 months, the 1-year survival rate was 82% (95% CI, 66%-98%), and the 2-year survival rate was 64% (95% CI, 44%-84%).
Conclusion: The results suggest that the new formulation of L-BLP25 has a safety profile similar to the original formulation and is safe to use in the phase III clinical development program.