Neoadjuvant Pembrolizumab Before Surgery in Muscle-Invasive Bladder Carcinoma
Posted: Monday, January 7, 2019
According to a study conducted by Andrea Necchi, MD, of the Fondazione Istituto di Ricovero e Cura a Carattere Scientifico, Milan, Italy, neoadjuvant pembrolizumab before radical cystectomy may prove to be of benefit to patients with muscle-invasive bladder carcinoma. Featured findings from this study, which was published in the Journal of Clinical Oncology, included a complete pathologic response (pT0) observed in 42% of patients.
In the phase II PURE-01 trial, 50 patients were enrolled over 11 months and received 3 cycles of pembrolizumab at a dose of 200 mg every 3 weeks before radical cystectomy. All patients had a predominant urothelial carcinoma histology and T≤3bN0 stage tumors.
A complete pathologic response was reported in 21 patients (42%), and downstaging of the tumor to pT<2 was noted in 27 patients (54%). As for the 35 patients with a PD-L1 combined positive score (CPS) of at least 10%, pT0 was achieved in more than half (19 patients), compared with 2 of 15 patients (13.3% of those with a CPS less than 10%.
A significant nonlinear association was seen between tumor mutation burden (TMB) and pT0. No correlation was observed between PD-L1 expression and TMB.
As for toxicity, the most common adverse event of any grade with pembrolizumab therapy was thyroid dysfunction (18%). Of the 3 patients who had grade 3 adverse events, treatment was discontinued in 1 of them (transaminase elevation).
Disclosure: The study authors’ disclosure information may be found at ascopubs.org.