Chinese Study Reports Promising Early Data on Toripalimab in TNBC

Anti–PD-1 monoclonal antibody toripalimab combined with paclitaxel appears to prolong survival in patients with stage IV or recurrent/metastatic triple-negative breast cancer (TNBC), according a press release from Shanghai Junshi Biosciences on findings from a prespecified interim analysis of the phase 3 TORCHLIGHT study (NCT04085276).

"These results demonstrate that the combined use of the monoclonal antibody toripalimab with traditional chemotherapy significantly prolonged the PFS of patients [with TNBC]," according to an expert from the Chinese People’s Liberation Army General Hospital.

Compared with albumin-bound paclitaxel injection alone, investigators found that toripalimab in combination with paclitaxel injection can significantly prolong progression-free survival (PFS) in patients with PD-L1–positive disease at initial diagnosis of stage IV or recurrent metastatic TNBC.

The interim analysis also identified a trend of improved overall survival (OS) in the toripalimab arm in the PD-1–positive population and regardless of PD-1 status. Toripalimab’s toxicity profile was consistent with previously reported risk; investigators did not identify any new safety signals.

As such, the Independent Data Monitoring Committee determined that the primary end point of OS measure met its predefined efficacy boundary.

“The TNBC subtype of breast cancer is the most aggressive and has the worst prognosis,” principal investigator Zefei Jiang, MD, professor in the Department of Oncology at the Chinese People’s Liberation Army General Hospital, and vice president and secretary general of the Chinese Society of Clinical Oncology (CSCO), said in the press release.

“These results demonstrate that the combined use of the monoclonal antibody toripalimab with traditional chemotherapy significantly prolonged the PFS of patients. This has the potential to become a new standard treatment for patients with an initial diagnosis of stage IV TNBC as well as those with recurrent/metastatic TNBC….”

Toripalimab was designed to block interactions between PD-1 and its ligands—PD-L1 and PD-L2—and enhance receptor internalization. It was the first anti–PD-1 antibody approved in China.

As part of the multicenter, randomized, open-label TORCHLIGHT study, patients in both groups received intravenous nab-paclitaxel at 125 mg/m2 on days 1 and 8, and then every 3 weeks thereafter. Patients in the experimental group additionally received intravenous toripalimab at 240 mg every 3 weeks; those in the control group received matched placebo.

To enroll, patients needed to present with estrogen receptor–negative, progesterone receptor–negative, and HER2-negative breast cancer. They also needed to be eligible for treatment with taxane monotherapy and have not received more than 1 line of chemotherapy in the metastatic setting. Other inclusion criteria included having an ECOG performance status of 0 or 1 and a life expectancy of at least 12 weeks.

The study excluded patients who received any prior taxane as a first-line treatment, as well as those previously treated with any PD-1, PD-L1, PD-L2, or CTLA4 antibodies. Other exclusion criteria included any confirmed active or untreated brain metastases and any meningeal carcinomatosis.

A biologics license application for toripalimab in combination with gemcitabine/cisplatin for frontline advanced recurrent or metastatic nasopharyngeal carcinoma and as a monotherapy for the same condition in the second-line setting or later, after platinum-containing chemotherapy is under review by the FDA.

Reference

Junshi Biosciences announces toripalimab in combination with chemotherapy for treatment of advanced triple-negative breast cancer met primary endpoint in phase 3 clinical study. News Release. Shanghai Junshi Biosciences Co., Ltd. February 20, 2023. Accessed February 22, 2023. https://yhoo.it/3xHpaK2