Phase II study in patients with diffuse large B cell lymphoma (DLBCL)
In this open‑label, non‑randomized, international Phase II study in 72 patients with DLBCL following autologous stem cell transplantation, pidilizumab treatment was shown to result in a progression-free survival of 72% and overall survival of 84% 18 months after transplant. Among the 27 high-risk patients who remained PET positive after salvage chemotherapy, the 18-month progression-free survival was 69%. Among the 40 patients with measurable disease after transplant, the overall response rate after pidilizumab treatment was 45%. Treatment was associated with early and persistent increases in specific subsets of circulating lymphocytes. Efficacy data compare favorably with previously reported cohorts and suggest that treatment with pidilizumab after autologous transplant may represent a promising therapeutic strategy in this disease.
Phase II study in patients with follicular lymphoma
A Phase II study was conducted in 30 adult patients with rituximab-sensitive, grade 1–2 follicular lymphoma who relapsed after 1-4 prior therapies with measurable disease. Pidilizumab was administered at 3 mg/kg IV every 4 weeks for 12 infusions and rituximab was dosed at 375 mg/m2 IV weekly for 4 weeks starting 2 weeks after the first infusion of pidilizumab. The combination was well-tolerated, with no autoimmune or therapy-related grade 3/4 toxicities. The most common grade 1 adverse events were anemia (14 patients) and fatigue (13 patients), and the most common grade 2 adverse event was respiratory infection (5 patients). Of the 29 patients eligible for efficacy analyses CR was observed in 15 (52%) and PR in 4 (14%) for an ORR of 66%; overall, tumor regression was noted in in 25/29 (86%) of the patients. The median response duration for the 19 responders was 20.2 months (95% CI: 13.9 months to not reached). Median progression-free survival was 18.8 months (95% CI: 14.7 months to not reached). Correlative studies of blood and tumor provided insights into predicting response and understanding mechanisms involved.
Phase I/II study in patients with diffuse intrinsic pontine glioma (DIPG)
Preliminary data were presented on June 13, 2016 in an oral symposium at the International Symposium on Pediatric Neuro-Oncology (ISPNO), Liverpool, UK. Data from 9 pediatric patients with DIPG who were treated with pidilizumab following completion of standard radiation therapy were presented. The only reason for non-accrual was parent’s decision.
Eight patients had intermediate risk features and one patient had high risk features (based on criteria by Jansen MH et al., Neuro-oncology, 17(1), 160–166, 2015). The reported median EFS and OS were 9.3 and 16.5 months, respectively. Three patients with DIPG remained progression-free at 16.3, 22, and 24 months following diagnosis, with one of the 3 patient experiencing a partial response.
Adverse events of any grade reported in at least one treatment cycle include neutropenia, fatigue, loss of appetite, hypertension, nausea, and lymphopenia; only neutropenia and hypertension were reported as grade 3 adverse events.