A new immunotherapy, toripalimab, has the potential to change practice in the treatment of nasopharyngeal carcinoma (NPC), say experts.
The drug is a monoclonal antibody that blocks programmed cell death protein 1 (PD-1), developed in China and recently approved there for the third-line treatment of NPC, among other indications. The U.S. Food and Drug Administration has granted it a breakthrough therapy designation for recurrent/metastatic NPC, as well as fast-track and orphan drug status for other tumor types.
New results show that when toripalimab was added onto chemotherapy with gemcitabine and cisplatin in the first line for recurrent or metastatic nasopharyngeal carcinoma, there was a significant improvement in both progression-free survival and overall survival.
The results come from the phase 3 trial dubbed JUPITER-02 and will be presented at the plenary session of the American Society of Clinical Oncology annual meeting this Sunday; some details were released earlier at a press briefing
The trial randomly assigned 146 patients to toripalimab and 143 to placebo on a background of gemcitabine and cisplatin, the current standard of care for recurrent/metastatic NPC.
Median progression-free survival (PFS) was 11.7 months with toripalimab vs. 8 months with placebo, a significant improvement (hazard ratio, 0.52; 95% confidence interval, 0.36-0.74. P = .0003). Overall survival was not mature at reporting but favored toripalimab with 25 deaths versus 39 in the placebo group, a 40% risk reduction (P = .0462).
The results “support the use of toripalimab in combination with [gemcitabine and cisplatin] as a new standard of care for first-line treatment of recurrent or metastatic nasopharyngeal carcinoma,” said lead investigator and medical oncologist Rui-Hua Xu, MD, PhD, of the Sun Yat-sen University Cancer Center in Guangzhou, China.
Potential to change practice
The significance of the study is that it used immunotherapy in the first-line setting for NPC instead of the second line where it’s frequently used today, commented Jared Weiss, MD, an associate professor of oncology and a head and neck cancer specialist at the University of North Carolina, Chapel Hill.
If FDA approves toripalimab for the indication, it “would change [first-line] standard of care to the triplet regimen,” he said in an interview.
The discussant for this presentation, Julie Gralow, MD, agreed. “This is one of the first studies in metastatic or recurrent NPC to show a benefit” for combining a PD-1 inhibitor with chemotherapy.
“With FDA approval, these findings should prove practice-changing,” said Dr. Gralow, a professor of breast medical oncology at the University of Washington, Seattle, and ASCO’s chief medical officer.
Toripalimab, dosed at 240 mg in the trial, or placebo were administered with gemcitabine and cisplatin every 3 weeks for up to 6 cycles, followed by toripalimab or placebo maintenance every 3 weeks until disease progression, intolerable toxicity, or completion of 2 years of treatment.
The overall response rate was 77.4% with toripalimab and 66.4% with placebo, and the median duration of response in the toripalimab group was 10 months vs. 5.7 months with placebo.
One-year PFS was 49.4% with toripalimab versus 27.9% with placebo; improved PFS was observed with toripalimab across PD-L1 subgroups.
Grade 3 or worse adverse events occurred in slightly less than 90% of both groups, with fatal adverse events occurring in slightly less than 3% in both.
Adverse events leading to discontinuation occurred in 7.5% of the study group and 4.9% on placebo. As expected with immunotherapy, immune-related adverse events such as hypothyroidism were more common with toripalimab (39.7% vs. 18.9%), as were grade 3 or worse immune-related adverse events (7.5% vs. 0.7%).
At interim analysis in May 2020, the median duration treatment was 39 weeks in the toripalimab group and 36 weeks in the placebo group.
The trial was conducted in China, Taiwan, and Singapore.
JUPITER-02 was funded by Shanghai Junshi Bioscience. Investigator disclosures weren’t reported. Dr. Weiss said he had no relevant disclosures. Dr. Gralow is an advisor for a number of companies, including Genentech, Novartis, and Roche.
A version of this article first appeared on Medscape.com.