GSK Singapore is pleased to announce that the Singapore Health Sciences Authority (HSA) has approved a new indication for Jemperli (dostarlimab). Jemperli can now be used in combination with carboplatin and paclitaxel, followed by Jemperli as a single agent for the treatment of adult patients with primary advanced or recurrent endometrial cancer that is mismatch repair deficient (dMMR) or microsatellite instability-high (MSI-H).

Endometrial cancer has been reported as the fourth most common cancer and has the ninth highest cancer mortality rate among females in Singapore, according to the latest Singapore Cancer Registry data from 2017-2021. During this period, 3,133 new cases were diagnosed. Globally, an estimated 20-29% of all endometrial cancers are dMMR/MSI-H, with approximately 28% of cases in Singapore diagnosed at an advanced disease stage. The current standard of care for these patients has been chemotherapy alone, but many patients eventually experience disease progression.

Dr. Stephanie Cinthu Stephen Ambrose, Medical Director at GSK Singapore, stated: "Singapore's expanded regulatory approval of Jemperli redefines the treatment landscape for patients with dMMR/MSI-H primary advanced or recurrent endometrial cancer. Until now, chemotherapy alone has been the standard of care, with many patients experiencing disease progression. In GSK's RUBY trial, Jemperli plus chemotherapy demonstrated a 72% reduction in the risk of disease progression or death versus chemotherapy alone, providing a statistically significant and clinically meaningful benefit. These results underscore the potential for Jemperli to transform cancer treatment as a backbone immuno-oncology therapy."

Dr. John Chia of Curie Oncology, Singapore, added: "Metastatic endometrial cancer is an aggressive disease with poor outcomes, and doctors sometimes struggle with limited effective treatment options. The results of the RUBY trial represent a clinical breakthrough in decades for dMMR/MSI-H endometrial cancer. With this newly approved treatment combination, many patients with primary advanced or recurrent dMMR endometrial cancer in Singapore will now have an opportunity for potential complete remission, with maximal benefit when given early in the treatment."

The HSA's approval is based on interim analysis results from Part 1 of the RUBY/ENGOT-EN6/GOG3031/NSGO Phase III trial, which included a robust median duration of follow-up of ≥ 25 months. The trial met the primary endpoint of investigator-assessed progression-free survival (PFS), demonstrating a statistically significant and clinically meaningful benefit in patients treated with Jemperli plus carboplatin and paclitaxel in the dMMR/MSI-H population. In this population, a 72% reduction in the risk of disease progression or death was observed.

The safety and tolerability profile for Jemperli plus carboplatin and paclitaxel was generally consistent with the known safety profiles of the individual agents. The most common treatment-emergent adverse events (≥ 20%) in patients receiving Jemperli plus chemotherapy were rash, diarrhea, hypothyroidism, and hypertension.