In the wake of increasing competition for its skin cancer therapy Zelboraf, Roche was boosted by data suggesting the drug could get a boost from combination use with pipeline drug cobimetinib.
Combining Zelboraf (vemurafenib) with cobimetinib significantly improved progression-free survival (PFS) compared to Zelboraf alone, according to the results of the phase III coBRIM trial, which included patients with previously untreated BRAF V600 mutation-positive melanoma.
Cobimetinib – originally developed by Exelixis – is a compound in the MEK inhibitor class. Other drugs in this class include GlaxoSmithKline’s Mekinist (trametinib), which is already approved in the US and EU as a melanoma therapy.
Mekinist and other recently-approved melanoma drugs, such as Bristol-Myers Squibb’s (BMS) Yervoy (ipilimumab) and GSK’s Tafinlar (dabrafenib), have started to eat into the sales of Zelboraf, a BRAF inhibitor which was first launched in 2011 and rapidly became the standard of care for melanoma in the US and Europe.
It has grown steadily since to reach 354m Swiss francs ($397m) in sales last year, but in the first quarter of 2014 Zelboraf showed signs of weakness, with sales slipping 2 per cent to 79m Swiss franc on a worldwide basis and sliding 40 per cent in the US.
Meanwhile, competition is only expected to get increasingly fierce following the launch of the first in the new PD1 inhibitor class, Ono Pharmaceutical/BMS’ Opdivo (nivolumab), in Japan. Merck & Co is also on course to win approval for its PD1 inhibitor pembrolizumab for melanoma by the end of this year.
“Despite great progress in our understanding and therapy in recent years, advanced melanoma remains a difficult and deadly disease that requires more treatment options,” said Sandra Horning, Roche’s chief medical officer.
“These encouraging data support the potential combined use of cobimetinib with Zelboraf to block tumour growth longer than Zelboraf alone,” she added.
Roche suggested earlier this year that positive results in coBRIM could set cobimetinib on track for regulatory filings before the end of 2014, while analysts at Maxim Group believe peak sales of the drug could reach $790m.
The drug is also being developed in combination with other agents in other tumour types, including non-small cell lung cancer (NSCLC) and colorectal cancer.