Pembrolizumab–bevacizumab combo works against nasopharyngeal carcinoma

The combination of pembrolizumab plus bevacizumab shows promising activity against platinum-resistant nasopharyngeal carcinoma while having manageable toxicities, according to an open-label phase II study conducted in Singapore.

The study included 48 adult patients (median age 56 years, 83 percent male) with platinum-resistant recurrent or metastatic nasopharyngeal carcinoma and had an Eastern Cooperative Oncology Group (ECOG) performance status of 0–1. These patients were randomly assigned to receive either intravenous pembrolizumab 200 mg alone (monotherapy, n=24) or in combination with intravenous bevacizumab 7.5 mg/kg (combination, n=24).

Pembrolizumab was given intravenously every 21 days, while bevacizumab was administered 1 week prior to each dose. Treatment lasted until radiographic disease progression, unacceptable toxicity, completion of 32 cycles, or withdrawal of consent.

Over a median follow-up of 28.3 months, the objective response rate was significantly higher in the combination group than in the monotherapy group (58.3 percent vs 12.5 percent; unadjusted rate ratio, 4.67, 95 percent confidence interval, 1.54–14.18; p=0.0010).

Grade 3 treatment-related adverse events (AEs) were reported in two (8 percent) patients in the monotherapy group and in seven (29 percent) in the combination group. Thrombosis or bleeding was the most common grade 3 treatment-related AEs, occurring in four (17 percent) patients in the combination group vs none in the monotherapy group. Other AEs reported were transaminitis, colitis, cytopenias, dermatological toxicities, hypertension, and proteinuria. None of the patients in either group had grade 4 treatment-related AEs. There were no treatment-related deaths.