GlaxoSmithKline (NYSE:GSK) is readying regulatory submissions for two melanoma treatments based on successful phase 3 clinical trial results of the experimental gene-inhibiting cancer drugs.
GSK is presenting the clinical trial results for dabrafenib and trametinib Monday at the annual conference of the American Society of Clinical Oncology, or ASCO. The phase 3 data for trametinib were also published online in the New England Journal of Medicine.
[Approval of the two drugs could produce as much as $2.35 billion in 2020, Bloomberg news reported Andrew Baum, a London-based analyst at Citigroup Inc., as saying in a note to investors last week.]
The drugs were studied in melanoma patients expressed mutations on the BRAF gene. Dabrafenib is a BRAF inhibitor. Tramatinib is an inhibitor of the MEK protein.
Patients studied with both drug candidates showed statistically significant benefit in how long they lived without their disease progressing — progression free survival — compared to those patients receiving chemotherapy. In the study of trametinib, patients who received that GSK compound showed longer overall survival than those who received chemotherapy with dacarbazine, a cancer drug used to treat melanoma. Overall survival data for dabrafenib are not yet ready.
Dr. Rafael Amado, head of oncology R&D for GSK, said that trametinib is the first MEK inhibitor to demonstrate clincial benefit in a late phase melanoma trial.
Besides studying dabrafenib and trametinib as separate cancer drugs, GSK is also studying the compounds in combination. (Read details from Bloomberg here.)
The British pharmaceutical company, which has its U.S. headquarters in Research Triangle Park, last week announced the start of a phase 3 trial that will evaluate the combination drug against a placebo and as well as head-to-head against Roche’s BRAF inhibitor vemurafenib, marketed as Zelboraf. Amado previously said that tumors become resistant to inhibitors. GSK believes the combination of a MEK inhibitor with a BRAF inhibitor may delay that resistance.