(Reuters) - Merck & Co on Wednesday said U.S. regulators intend to rescind the “breakthrough therapy” designation for its combination treatment for hepatitis C because other new drugs are available, a decision that could delay approval of the Merck product by several months.
The Food and Drug Administration gives the designation to medicines it deems likely to demonstrate “substantial improvement” over existing drugs. The designation has hastened approval of some drugs by two to three months.
Analysts said Merck’s two-drug treatment would likely now require a standard 10-month review.
Merck, in its fourth-quarter earnings report, said it plans to discuss the matter with the FDA and still expects to seek U.S. approval in the first half of 2015. The treatment consists of a protease inhibitor called MK-5172 and a so-called NS5A inhibitor called MK-8742 that together had received the FDA’s “breakthrough therapy” designation.
In a recent mid-stage trial, Merck’s combo cured 98 percent of previously untreated patients with genotype 1, the most common and hardest to treat variant of hepatitis C. Merck said late-stage trials are now complete, and will support approval.
“Based upon data today, we believe we will be able to compete in the marketplace,” Adam Schechter, head of global human health for Merck, said in an interview.The setback for Merck follows recent approvals of costly oral treatments for the liver disease from Gilead Sciences Inc and AbbVie Inc that have wiped out all signs of the virus in well over 90 percent of patients after eight or 12 weeks.
“The breakthrough therapy designation is meant for drugs that address an unmet medical need, but we now have two virtual cures for hepatitis C on the market” from Gilead and AbbVie, said Edward Jones analyst Ashtyn Evans.
Evans said Merck’s combination treatment will likely undergo a standard FDA review. She predicted, however, that Merck’s array of experimental hepatitis C drugs will eventually claim a 15 to 20 percent global market share, with annual sales in the billions of dollars.
Shares of the second-biggest U.S. drugmaker fell 3.5 percent on Wednesday, also hurt by a weaker-than-expected profit forecast for 2015 which the company blamed on the stronger dollar.
In the face of such potent rival hepatitis C medicines, Merck in June announced it would ramp up its involvement in the lucrative field by buying Idenix Pharmaceuticals Inc for $3.85 billion and combining the two companies’ most promising drugs to produce a faster, more effective cure.
Idenix had three hepatitis C drugs in development, most notably a pill in early-stage trials called IDX21437, which Merck has renamed MK-3682. Like Gilead’s Sovaldi, it is a nucleotide inhibitor, or “nuc,” that blocks a protein needed by the hepatitis C virus to replicate.
Merck is conducting a mid-stage trial to study combinations of MK-3682 and MK-5172 (grazoprevir) with either MK-8742 (elbasvir) or another drug called MK-8408. It hopes to begin larger late-stage trials of the triplet therapies this year.
Gilead introduced Sovaldi in late 2013 at a cost of $1,000 a pill, and reported fourth-quarter sales of $1.73 billion for the drug. Gilead later introduced Harvoni, a pill combining Sovaldi with another treatment, and it captured sales of $2.11 billion in the quarter.
AbbVie launched its Viekira Pak treatment late last year. Since then, it has battled Gilead for market share by offering discounts to insurers and other group payers.
Late on Tuesday, Gilead disclosed that its discounts will average 46 percent this year, up sharply from analyst expectations of 25 to 30 percent. Shares of Gilead and AbbVie both tumbled after the news.
As many as 3.2 million people in the United States are estimated to be infected with the hepatitis C virus, which can lead to severe liver disease.
Merck on Wednesday reported slightly disappointing fourth-quarter sales and predicted 2015 earnings below analyst forecasts. It cited the negative impact of the stronger dollar, as most of its U.S. rivals have done in their own cautious forecasts.
Reporting by Ransdell Pierson; Editing by W Simon, Paul Simao and David Gregorio