Gilead Sciences’ once-daily hepatitis C regimen could soon have company. Merck & Co, lost in the pack of this hotly contested race, disclosed phase II data from its combination of MK-5172 and MK-8742 showing that the pairing can achieve viral suppression rates above the 90% threshold now considered to be the minimum to pass muster with physicians.
Merck’s pairing has yet to show the pan-genotypic effectiveness of Gilead’s Sovaldi and lepidasvir, and so far remains a two-pill strategy to Gilead’s fixed-dose combination. But the data release at EASL showed how overlooked the New Jersey group has been in this race, with a consensus view of its hep C sales coming in at less than $200m in 2018. Shares opened 2% higher this morning after a strong 4% rise yesterday.
Merck presented interim data from the C-Worthy programme that paired MK-5172, a second-generation protease inhibitor, with MK-8742, a nucleoside NS5A inhibitor, in treating genotype 1 patients; this is the most common genotype in North America and patients have some of the most resistant infections. The patients in the trial had never before been treated for their disease.
The 80 patients who received the Merck regimen added to the hep C mainstay ribavirin achieved a sustained viral response (SVR) of 94% after 12 weeks of treatment. Without ribavirin, an SVR of 98% was reached in 43 participants, suggesting that ribavirin is not a necessary addition for the eradication of the virus in this patient type.
These results are on a par with those seen with Sovaldi or Johnson & Johnson’s Olysio (Sovriad) in various combinations with ribavirin and interferon, as well as AbbVie’s three-drug regimen, which is nearing the end of its phase III programme.
With a shorter treatment regimen of eight weeks, the Merck drug's SVR was 83%, with a 17% relapse rate. This suggests that this will not be an avenue Merck pursues with the phase III C-Edge programme, which will add genotypes 4, 5 and 6 as well as HIV co-infected patients to the mix.
Not over 'til it's over
The findings show that plenty of companies still want to fight for a share of the 170 million people worldwide estimated to be infected. Almost every group has been overshadowed by the speedy progress of Gilead, not least because the group was willing to spend $11bn to put itself in the lead when it purchased the company that discovered Sovaldi.
EvaluatePharma’s consensus shows that analysts have yet to pencil in forecasts for MK-8742, with just $35m for ‘5172 and $15m for the filed protease inhibitor vaniprevir in 2018. ISI Group analyst Mark Schoenebaum wrote today that he expected analysts at least to triple their forecasts for Merck’s hep C assets as a result of these new data.
Gilead cannot expect to have the market all to itself, and more competition combined with the recent furore raised about Sovaldi’s $84,000 price tag might have it rethinking its next launch strategy.