Pasotuxizumab, a Bite <sup>®</sup> Immune Therapy for Castration-Resistant Prostate Cancer: Phase I, Dose-Escalation Study Findings
Horst-Dieter Hummel, Peter Kufer, Carsten Grüllich, Ruth Seggewiß-Bernhardt, Barbara Deschler-Baier, Manik Chatterjee, Maria-Elisabeth Goebeler, Kurt Miller, Maria De Santis, Wolfgang Loidl, Christian Dittrich, Andreas K. Buck, Constantin Lapa, Annette Thurner, Sabine Wittemer‐Rump, Gökben Koca, Oliver Boix, Wolf‐Dietrich Döcke, Ricarda Finnern, Helena Kusi, Antoinette Ajavon‐Hartmann, Sabine Stienen, Cyrus Sayehli, Bülent Polat, Ralf C. Bargou
Abstract
Aim: We report results of a first-in-human study of pasotuxizumab, a PSMA bispecific T-cell engager (BiTE®) immune therapy mediating T-cell killing of tumor cells in patients with advanced castration-resistant prostate cancer. Patients & methods: We assessed once-daily subcutaneous (SC) pasotuxizumab. All SC patients developed antidrug antibodies; therefore, continuous intravenous (cIV) infusion was assessed. Results: A total of 47 patients received pasotuxizumab (SC: n = 31, 0.5–172 μg/d; cIV: n = 16, 5–80 μg/d). The SC maximum tolerated dose was 172.0 μg/d. A sponsor change stopped the cIV cohort early; maximum tolerated dose was not determined. PSA responders occurred (>50% PSA decline: SC, n = 9; cIV, n = 3), including two long-term responders. Conclusion: Data support pasotuxizumab safety in advanced castration-resistant prostate cancer and represent evidence of BiTE monotherapy efficacy in solid tumors.Clinical trial registration: NCT01723475 (ClinicalTrials.gov)