Business Context and Reporting Period
Company: GlaxoSmithKline plc (GSK)
Filing Type: Form 6-K (Report of Foreign Issuer)
Date: July 17, 2014
Subject: Announcement regarding the early termination of the Phase III COMBI-v clinical study for the combination of trametinib (Mekinist) and dabrafenib (Tafinlar) in the treatment of metastatic melanoma.
Key Financial Metrics
This filing is a current report regarding clinical trial results and does not contain financial statements. The filing text does not provide values for revenue, profit, cash flow, margins, debt, or liquidity.
Material Changes and Clinical Results
The Independent Data Monitoring Committee (IDMC) recommended stopping the COMBI-v Phase III study early due to a demonstrated overall survival benefit for the trametinib and dabrafenib combination compared to vemurafenib. Key details include:
- Study Outcome: The combination therapy crossed the pre-specified efficacy stopping boundary for overall survival.
- Study Design: Randomized, open-label study enrolling 704 patients with BRAF V600E or V600K mutation-positive unresectable or metastatic cutaneous melanoma.
- Next Steps: Patients randomized to the vemurafenib arm are permitted to cross over to receive the trametinib and dabrafenib combination. Further analysis of safety and efficacy data is underway.
Outlook, Risks, and Safety Profile
Management commentary indicates that these results add to the evidence characterizing the efficacy and safety of the combination therapy. The filing includes extensive safety warnings regarding the combination of Mekinist and Tafinlar:
- New Primary Malignancies: Increased incidence of basal cell carcinoma (9% vs 2% for Tafinlar alone) and cutaneous squamous cell carcinoma (7% vs 19% for Tafinlar alone).
- Haemorrhage: Increased incidence and severity (16% vs 2%); intracranial haemorrhage was fatal in 4% of combination patients.
- Cardiomyopathy: Occurred in 9% of combination patients versus 0% for Tafinlar alone.
- Venous Thromboembolic Events: Deep vein thrombosis and pulmonary embolism occurred in 7% of combination patients versus 0% for Tafinlar alone.
- Febrile Reactions: Fever occurred in 71% of combination patients versus 26% for Tafinlar alone; serious febrile reactions with hypotension occurred in 25% vs 2%.
- Other Risks: Ocular toxicities (Retinal Vein Occlusion, Retinal Pigment Epithelial Detachment), Interstitial Lung Disease, and Hyperglycaemia.
Investor Verification Checklist
- Verify the final analysis of safety and efficacy data once completed in the coming months.
- Confirm regulatory approval status for the combination therapy in markets outside the U.S. and Australia.
- Monitor the crossover rate of patients from the vemurafenib arm to the combination therapy.
- Review the long-term safety profile regarding new primary malignancies and cardiomyopathy as more data becomes available.
- Assess the potential commercial impact of the combination therapy on GSK's oncology portfolio relative to competitor vemurafenib.