Abstract CT047: Phase I trial of intravesical Bacillus Calmette-Guérin combined with intravenous Pembrolizumab in high grade nonmuscle invasive bladder cancer

Abstract

Abstract PURPOSE: A phase I trial of intravesical bacillus Calmette-Guérin (BCG) in combination with systemic pembrolizumab was conducted in patients with high grade non-muscle invasive bladder cancer who had persistent or recurrent disease after failing treatment with at least 2 courses of intravesical therapy (one of which had to contain BCG) or BCG followed by maintenance BCG. The primary objective was to determine the safety of this combination. Secondary end points included response to treatment at 19 weeks (end of treatment) and 3 months post treatment. MATERIALS AND METHODS: A total of 9 patients with recurrent/persistent high-grade non-muscle invasive bladder cancer after at least two courses of intravesical therapy or one course of BCG treatment followed by one course of maintenance BCG were enrolled in the study. Six doses of pembrolizumab were given every 3 weeks over 16 weeks given concurrently with 6 weekly doses of BCG beginning at week 7. Patient safety was evaluated during and for 30 days following pembrolizumab treatment. Preliminary combination efficacy was determined at 19 weeks using cystoscopy. Bladder biopsy was performed in patients with suspicious lesions. RESULTS: The combination of BCG and pembrolizumab was well tolerated at both 100mg and 200mg fixed doses. Fatigue and cystitis-type symptoms (burning, spasm, urgency, sensitivity, and frequency) were the most common adverse events and all cases were either grade 1 or 2. Two patients died during the trial period. One patient died due to progression of low grade upper urinary tract transitional cell carcinoma. The other patient died after cystectomy (for progressive disease) due to causes unrelated to the trial treatment. Of the 9 patients treated, 6 (78%) had no evidence of disease in the bladder and 1 had a mixed response (progression in the upper urinary tract only) at 19 weeks (end of treatment) while 5 (56%) remained disease-free at the 3 month follow up. CONCLUSIONS: The combination of BCG and pembrolizumab was well tolerated with subjects exhibiting the expected adverse effects associated with the use of both medications. Intravesical BCG and pembrolizumab may have clinical activity in non-muscle invasive bladder cancer recurring after repeated intravesical therapy. .A phase III trial is now open and enrolling in the United States and other countries (NCT03711032). Citation Format: Shaheen Alanee, Ahmed El Zawahry, Sherjeel Sana, Kevin McVary, Kathy Robinson, Krishna A. Rao. Phase I trial of intravesical Bacillus Calmette-Guérin combined with intravenous Pembrolizumab in high grade nonmuscle invasive bladder cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr CT047.