Merck HCV med's efficacy matches competitors'

Merck
Merck

New data for Merck's doublet HCV medicine—grazoprevir and elbasvir—paint a competitive picture of the company's efforts to develop a drug for the liver-destroying disease.

Merck plans to present the data at the International Liver Congress in Vienna on Friday.

In a study of 316 patients, 95% were cured or achieved sustained virologic response after 12 weeks (SVR12) of treatment, according to data published in the Annals of Internal Medicine. The Phase-III trial included patients with and without liver damage—97% of the patients with cirrhosis were cured after 12 weeks, and 94% without cirrhosis were cured in the same time period.

Those results aren't far off from current market leaders. Grazoprevir-elbasvir had similar efficacy when compared to Gilead's Harvoni. Trials for Harvoni show SVR12 rates ranging from 96 to 99% in patients without liver damage, and 96% in those with some form of cirrhosis. The doublet was similarly effective treating genotype 4 patients compared to AbbVie's Viekira Pak, too. Merck's doublet cured 100% of genotype 4 patients in this trial; Viekira Pak trials show SVR12 rates ranging from 91% to 100%.

While the drug boasts strong efficacy, Merck faces an uphill battle promoting grazoprevir-elbasvir with three 12-week treatment regimens already available: Sovaldi, Harvoni and Viekira Pak. Sovaldi brought in US sales of $7.9 billion in 2014, while Harvoni—which was approved in October—saw global sales of $2.1 billion in its first three months. Viekira Pak is expected to reach annual sales of $2 to $3 billion by the end of 2015.

Merck plans to look toward the margins of the hepatitis-C patient population with this regimen. The drugmaker recently scored a breakthrough therapy designation in two subsets of the disease: genotype 1 patients who also suffer from advanced kidney disease and those with genotype 4 of the disease. The FDA had rescinded a breakthrough therapy designation granted to grazoprevir-elbasvir in February for use in genotype 1 (the most common genotype of the disease)—citing the availability of other treatments. Merck expects to file grazoprevir-elbasvir with the FDA by July.

Merck also presented data at the International Liver Congress from a Phase-II/III trial evaluating the drug in patients with advanced kidney disease. After 12 weeks of taking grazoprevir-elbasvir, 99% of the patients in the trial with advanced kidney disease were effectively cured.

Still, most analysts see Merck's future in the disease lying in its triplet combination therapy—grazoprevir-elbasvir paired with the NS5A inhibitor it acquired from Idenix Pharmaceuticals for $3.9 billion in June. Phase-III trials for the triplet are expected to start in the second half of this year.