Phase I Trial of Safety of Combining BCG with Pembrolizumab in Patients with High Grade Superficial Bladder Cancer Unresponsive to Previous Intravesical Therapy
Alanee SR, Robinson K, and Sana S. Phase I trial of safety of combining BCG with pembrolizumab in patients with high grade superficial bladder cancer unresponsive to previous intravesical therapy. J Clin Oncol 2018; 36(5) Suppl. 1
J. Clin Urol
Background: Bacille Calmette-Guerin (BCG) is the most effective agent in the treatment of high grade superficial bladder cancer (HGSBC); however, not all patients respond to BCG, and recurrent disease is associated with a poor prognosis. The blockade of immune checkpoints of the pathway involving programmed death 1 (PD1) has been shown recently to be effective in cancer therapy. We started the first trial in the United States to combine an anti-PD1 drug (pembrolizumab) with BCG therapy in patients with HGSBC. Methods: The primary objective of the study was to determine the safety of administering a 200 mg fixed dose of pembrolizumab in conjunction with intravesical BCG treatment in HGSBC patients who have failed two courses of induction therapy or one course of BCG induction therapy followed by maintenance therapy. Patients included had to have pathologically documented HGSBC (Ta, T1) at time of restaging, or have pathologically documented high grade CIS of the bladder at time of initial resection for recurrent/persistent bladder cancer. Subjects were treated with six cycles (21 day cycle) of pembrolizumab treatment combined with six consecutive weeks of concurrent BCG installation beginning with cycle 3 of pembrolizumab. The first three subjects were to be treated at a dose of 100 mg pembrolizumab to ensure safety for the combination. If no safety issues were to happen, dosing was to be escalated to 200 mg every three weeks. Our secondary objective was to determine the 19 week and the three, twelve, and twenty-four month post-treatment completion complete response rate. The first patient received cycle 1 of pembrolizumab treatment in July of 2015. As of the date of writing this letter, five patients have completed treatment on this trial. The trial is soon to open a second site at Henry Ford Health System in addition to Southern Illinois University with the goal of full enrollment to be achieved in the next 6 months.