The addition of the immunotherapy agent toripalimab to standard first-line chemotherapy significantly delayed disease progression for patients with recurrent or metastatic nasopharyngeal carcinoma (NPC), according to new research.

The phase III international study, to be presented at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting, may represent a paradigm shift in the care of these patients, for whom there are currently few treatment options.

NPC, a type of head and neck cancer that starts in the nasopharynx, represents a significant global health problem. The cancer is particularly prevalent in East and Southeast Asia, which accounted for more than 70% of the approximate 129,000 new diagnoses worldwide in 2018.

Platinum-based therapy is currently standard first-line treatment for recurrent or metastatic NPC. However, the duration of response is, on average, less than six months.

The JUPITER-02 trial demonstrated that the addition of the immunotherapy toripalimab to standard first-line chemotherapy lengthened the time to disease progression compared with placebo, with a median of 11.7 months versus 8.0 months, respectively.

In this phase III trial, 289 patients with recurrent or metastatic NPC, who had not received previous chemotherapy, were randomised 1:1 to receive toripalimab (146 patients) or placebo (143). Patients in both groups also received gemcitabine/cisplatin chemotherapy.

The study’s primary endpoint was PFS in all study patients. Secondary end points included overall response rate, duration of response, and overall survival (OS).

At 1 year, 49% of patients who received toripalimab had not experienced disease progression, compared to 28% of those who received placebo.

Serious adverse events (AEs) grade 3 or greater were similar for both groups — 89.0% for toripalimab versus 89.5% for placebo, with discontinuation of treatment in 7.5% of immunotherapy patients, compared to 4.9% that took placebo. Fatal AEs were similar between the two arms, 2.7% and 2.8%, respectively.

Immune-related AEs were more common with toripalimab, 39.7%, compared with placebo,18.9%. Immune-related AEs grade 3 or greater were also more common with toripalimab (7.5%) than with placebo (0.7%).

Toripalimab is an immune therapy known as a checkpoint inhibitor that works by blocking programmed cell death protein 1 (PD-1) found on the surface of immune cells, allowing the immune system to continue working properly.

“Nasopharyngeal carcinoma is challenging as it is typically diagnosed in an advanced stage when current therapy options are extremely limited. The extended response in patients that received with toripalimab marks a significant advance for treatment of this disease,” said Rui- hua Xu, MD, PhD, of the department of medical oncology at Sun Yat-sen University Cancer Center in Guangzhou, China.

“Treatment advances for late-stage nasopharyngeal carcinoma have lagged behind those of other cancers. Findings from the JUPITER-02 study offer new hope for patients with advanced disease, changing how we care for them,” said ASCO Chief Medical Officer and Executive Vice President Julie R. Gralow, MD, FACP, FASCO.

Patients will continue to be followed for OS and other secondary end points.

Source: American Society of Clinical Oncology (ASCO)