Camrelizumab shows durable overall survival benefits in nasopharyngeal carcinoma

by Michael Woodhead

 Adding the immune checkpoint inhibitor camrelizumab to chemotherapy improves five-year overall survival when compared to chemotherapy alone as first-line treatment of patients with recurrent or metastatic nasopharyngeal carcinoma (RM-NPC), a randomised controlled trial led by Guangdong researchers has confirmed.

PD-1 inhibitors plus chemotherapy are already the current standard first-line treatment of recurrent or metastatic nasopharyngeal carcinoma (RM-NPC) but their long-term survival benefits was uncertain, according to researchers, led by Professor Yan Huang from Sun Yat-sen University Cancer Center, Guangzhou, writing in JAMA Oncology.

To investigate long term survival rates, they conducted a secondary analysis of CAPTAIN-1st study, a randomised, double-blind, phase 3 trial conducted at 28 hospitals in China that involved 263 patients with RM-NPC.

In the trial, patients were randomised to receive camrelizumab or placebo in combination with gemcitabine and cisplatin for 4 to 6 cycles, followed by maintenance therapy with camrelizumab or placebo until disease progression, unacceptable toxic effects, or completion of two years of treatment.

Their results showed that after follow up of around 63 months, the addition of the PD-1 inhibitor to chemotherapy was associated with a “clinically meaningful” 35% reduction in deaths, with an eight month improvement in 5-year overall survival compared with chemotherapy alone.

The median overall survival at five years was 34.5 months (95% CI, 29.4-45.7) with camrelizumab vs 26.6 months (95% CI, 19.8-33.5) with placebo. The overall hazard ratio [HR] was 0.74, but after adjusting for age imbalance the HR was 0.65 (95% CI, 0.48-0.89; P = .01).

The overall five-year OS rates were 37.8% vs 24.2%, reflecting an absolute difference of 13.6% (95% CI, 2.4%-24.8%; P = .02) in favour of camrelizumab.

The study researchers noted that the OS benefits were generally consistent across subgroups. They also observed that rapid clearance of plasma Epstein-Barr virus DNA was a valuable prognostic biomarker of long-term survival, with a hazard ratio of 0.32; for give year overall survival patients in the camrelizumab group who achieved rapid clearance of EBV DNA compared with those without EBV DNA clearance

“These findings provide the first 5-year evidence to inform clinical practice on programmed cell death 1 protein–based chemoimmunotherapy in RM-NPC, supporting camrelizumab plus chemotherapy as the standard first-line treatment and establishing a new benchmark for long-term survival in this population,” the authors concluded.

This study was funded by Jiangsu Hengrui Pharmaceuticals, which markets camrelizumab under the brand name AiRuiKa. Camrelizumab is currently approved for nine indications in China, including nasopharyngeal carcinoma, HCC, relapsed/refractory classic Hodgkin’s lymphoma and oesophageal squamous cell carcinoma.