The FDA has approved pembrolizumab (Keytruda®, Merck) for the treatment of patients with high-risk non-muscle invasive bladder cancer (NMIBC) carcinoma in situ, with or without papillary tumors. Pembrolizumab, a programmed cell death protein 1 (PD-1) inhibitor, is indicated for patients who are ineligible for or have elected not to receive radical cystectomy and who do not respond to bacillus Calmette-Guérin (BCG) therapy.
The approval was based on Keynote 057 (NCT02625961), a multicenter, single-arm, open-label phase 2 trial that enrolled 148 patients with high-risk NMIBC, including 96 patients with BCG-unresponsive carcinoma in situ with or without papillary disease. The primary end point of the trial was complete response rate as assessed by cystoscopy, urine cytology, and computed tomography urography (CTU) imaging. Secondary end points included duration of response and safety. Patients received 200 mg of pembrolizumab once every three weeks for up to 24 months or until disease progression, recurrence, or unacceptable toxicity.
Pembrolizumab produced a complete response rate of 41% in patients with high-risk, BCG-unresponsive NMIBC carcinoma in situ. Responses lasted at least 12 months in 46% of patients who experienced a complete response, with a median duration of 16.2 months.
Adverse events occurring in at least 10% of patients included pruritis, rash, diarrhea, fatigue, nausea, musculoskeletal pain, hematuria, cough, urinary tract infection, nausea, arthralgia, nasopharyngitis, peripheral edema, and hypothyroidism.
"Pembrolizumab had encouraging activity in patients with high-risk, BCG-unresponsive carcinoma in situ with or without papillary tumors and a safety profile consistent with that of previous experience," concluded the Keynote 057 investigators in their presentation abstract from the 2019 Genitourinary Cancers Symposium, led by first author Arjun V. Balar, MD, Director of the Genitourinary Medical Oncology Program at NYU Langone Health's Perlmutter Cancer Center.
The recommended dosage of pembrolizumab is 200 mg once every 3 weeks.
For More Information
Balar AV, Kulkarnia GS, Uchio EM, et al (2019). Keynote 057: phase II trial of pembrolizumab (pembro) for patients (pts) with high-risk (HR) nonmuscle invasive bladder cancer (NMIBC) unresponsive to bacillus Calmette-Guérin (BCG). J Clin Oncol (2019 Genitourinary Cancers Symposium Abstracts), 37(suppl_7). Abstract 350. DOI:10.1200/JC0.2019.37.7_suppl.350
Clinicaltrials.gov. Efficacy and safety of pembrolizumab (MK-3475) in combination with bacillus Calmette-Guerin (BCG) in high-risk non-muscle invasive bladder cancer (HR NMIBC) (MK-3475-676/KEYNOTE-676). NLM identifier: NCT03711032.
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