Business Context and Reporting Period
This Form 6-K filing by GlaxoSmithKline plc (GSK) covers the period ending March 19, 2019. The document serves as an LSE Announcement regarding clinical trial data for dostarlimab, an investigational anti-PD-1 antibody developed by TESARO, an oncology-focused business acquired by GSK. The announcement details results from the Phase 1/2 GARNET study presented at the 2019 Society for Gynecologic Oncology Annual Meeting.
Key Financial Metrics
The filing text does not provide a clear value for revenue, profit, cash flow, margins, debt, or liquidity. This document is a clinical update and does not contain financial statements or performance metrics.
Material Changes and Clinical Findings
The primary material update concerns the efficacy and safety of dostarlimab in patients with advanced or recurrent endometrial cancer who progressed on or after platinum-based therapy. Key findings from the GARNET study include:
- Study Population: 125 patients analyzed, comprising 41 MSI-H (33%), 79 MSS (63%), and 5 with unknown MSI status.
- Overall Response Rates (irRECIST): 30% in the full population, 49% in the MSI-H population, and 20% in the MSS population.
- Disease Control Rates: 53% in the full population, 63% in the MSI-H population, and 47% in the MSS population.
- Durability: At data cutoff, 84% of responders were still on treatment. 89% of responders had been on treatment for over six months, and 49% for over one year. Median duration of response has not been reached.
- Safety Profile: 70.4% of patients experienced at least one treatment-emergent adverse event (TEAE). Most common TEAEs were fatigue (14.4%), diarrhea (12.8%), and nausea (12.0%). Only 13.6% experienced grade 3 or higher adverse events, with no treatment-related deaths.
Guidance, Outlook, and Risks
Regulatory Outlook: GSK plans to submit a Biologics License Application (BLA) for dostarlimab in endometrial cancer at the end of 2019. Further data analysis using RECIST 1.1 criteria will support this filing.
Management Commentary: Mary Lynne Hedley, President and COO of TESARO, stated that current treatment options for advanced endometrial cancer are limited. The data reinforces the potential of dostarlimab to address unmet needs in both MSI-H and MSS patient populations.
Risks and Contingencies: The filing includes a cautionary statement regarding forward-looking statements. Actual results may differ materially due to risks described in the company's 2018 Annual Report on Form 20-F. Dostarlimab is not currently approved for use anywhere in the world.
Investor Verification Checklist
- Verify the timeline and status of the planned BLA submission for dostarlimab in endometrial cancer expected at the end of 2019.
- Confirm the final regulatory decision on dostarlimab approval following the BLA submission.
- Monitor the long-term durability of response data as the median duration of response has not yet been reached.
- Review the safety profile in larger Phase 3 trials to confirm the tolerability observed in the Phase 1/2 GARNET study.
- Assess the commercial potential of dostarlimab in the MSS endometrial cancer market, where no approved treatments currently exist for recurrent disease.