Jemperli's (dostarlimab) indication was expanded to include its use as a first-line treatment in combination with platinum-based chemotherapy for all patients with advanced or recurrent endometrial cancer.

The drug is expected to further expand its influence, with the Health Insurance Review and Assessment Service's Cancer Disease Deliberation Committee passing the drug’s use as first-line treatment of advanced or recurrent dMMR/MSI-H endometrial cancer in combination with platinum-based chemotherapy in October.

On the 10th, GSK Korea announced that it had received approval from the Ministry of Food and Drug Safety (MFDS) to expand Jemperli’s indication to include all patients with advanced or recurrent endometrial cancer on the 9th.

This indication expansion allows Jemperli to be used as a first-line treatment for all patients with advanced or recurrent endometrial cancer, regardless of whether they have a mismatch repair defect (dMMR)/high-frequency microsomal instability (MSI-H).

The Phase III RUBY study, which became the basis of Jemperli’s approval, evaluated Jemperli in combination with platinum-based chemotherapy (carboplatin plus paclitaxel) versus placebo and platinum-based chemotherapy in 494 patients with advanced or recurrent endometrial cancer.

The study was designed to include at least 3 years of treatment given that the median survival for conventional platinum-based chemotherapy is less than 3 years. The primary endpoints were progression-free survival (PFS) and overall survival (OS) according to Response Evaluation Criteria in Solid Tumors (RECIST).

Study results showed that the Jemperli combination arm reduced the risk of death by 31% compared to the control arm in patients with advanced or recurrent endometrial cancer.

Over a median follow-up of 37 months, the median overall survival (OS) of patients receiving the Jemperli combination was 44.6 months, 16.4 months longer than the control arm (28.2 months), and the risk of death was reduced by 31%.

The safety profile was consistent with the last interim analysis, with no new safety information observed. The most common treatment-related adverse events were fatigue, hair loss, and nausea, most of which were mild to moderate.

Jae Kwan Lee, Professor at Korea University Guro Hospital (President, Korean Society of Gynecologic Oncology), said, “Endometrial cancer is a disease that carries a high risk of recurrence even after initial treatment. This is why an effective first-line treatment option is critical for the patients. The RUBY study is regarded as an important study that demonstrated the long-term effectiveness of immune-oncology drugs in endometrial cancer.”

Lee added, “Jemperli in combination with platinum-based chemotherapy is the only immuno-oncology agent available for the treatment of endometrial cancer in Korea that has been shown to improve OS. We look forward to seeing more patients benefit from the clinical value of Jemperli in the future, as we have shown significant clinical value even though the study included patients who relapsed 6 months after chemotherapy and patients with high-risk diseases such as carcinosarcoma.”

As a humanized IgG4 monoclonal antibody, Jemperli is a programmed death receptor-1 inhibitor (PD-1 inhibitor) that shows sustained antitumor activity in dMMR/MSI-H carcinoma.

It was approved by the Ministry of Food and Drug Safety in December 2022 for the treatment of adult patients with recurrent or advanced dMMR/MSI-H endometrial cancer who are on or have progressed after prior platinum-based systemic chemotherapy and is reimbursed by health insurance.