Though still in the early days since its Dec. 6 approval, Gilead Sciences' hepatitis C drug Sovaldi may be enjoying one of the most massive drug launches of all time. Current consensus calls for sales of $4.6 billion this year — and the whisper numbers are running even higher.
This doesn't surprise Wall Street, as Sovaldi provides a faster, safer and stronger alternative to a punishing yearlong regimen of interferon. But as analysts obsessively watch the weekly prescription numbers grow, they're also eyeing data from Sovaldi's potential challengers in a market that's estimated at $20 billion a year and growing.
Bristol-Myers Squibb's (BMY) daclatasvir grabbed headlines last April when a phase two trial combining it with Sovaldi scored a 100% cure rate.
But Gilead (GILD) elected not to pursue the combo further. Instead, it's studying Sovaldi in combination with its similar drug ledipasvir, so that it can co-formulate the two into a single pill and not share the market.
Bristol, however, filed in the European Union for approval of daclatasvir "for use in combination with other agents, including sofosbuvir" (the generic name for Sovaldi), and was granted accelerated review there in early January. The firm plans to submit a similar filing to the Food and Drug Administration soon.
Sovaldi Sets New Standard
In October, Bristol filed to approve a combo of daclatasvir with another of its drugs, asunaprevir, in Japan, which has an unusually high rate of hepatitis C virus (HCV) infection due to a formerly tainted blood supply.
Douglas Manion, Bristol's vice president of development, virology and Japan, says that the dual regimen scored good results, but its 24-week duration is looking like yesterday's news now that Sovaldi has set a 12-week standard. He hopes that will be resolved by a triple therapy involving daclatasvir, asunaprevir and a drug dubbed BMS-791325, co-formulated into one pill to be taken twice a day, now in phase three testing.
Ultimately, however, he does not expect a single regimen to conquer the others because not all patients are the same.
Treating Toughest Patients
"Daclatasvir has been studied with so many different drugs, it's used in all genotypes (of the hepatitis C virus) and all patient populations — especially the toughest-to-treat populations," Manion said. "These are going to be liver-transplant patients, genotype 3 patients, patients with cirrhosis, and ultimately patients with decompensation.
Decompensated cirrhosis, the worst form of liver damage that can result from HCV, usually results in liver transplant or death.
The decompensated group was one population not included in AbbVie's (ABBV) six phase three trials of its "3D" regimen combining three antiviral agents. AbbVie also stuck to the most common genotype, genotype 1. It did very well in the trials, with cure rates ranging from 90% to 100%. The company plans to file in the U.S. during the second quarter and hit the market late this year.
In one respect it will have nearly caught up with Gilead, because current FDA guidelines on Sovaldi recommend that it be used with interferon in genotype 1, unless the patient can't tolerate interferon. Gilead is banking on its sofosbuvir-ledipasvir combo to be its first official interferon-free genotype 1 treatment — also expected to launch later this year after a Feb. 10 filing.
Barry Bernstein, AbbVie's vice president of infectious disease development, touted 3D's strong safety profile and the fact that it cured upward of 92% of patients with compensated cirrhosis.
"We believe that the regimens will provide an option for any genotype 1-infected patient," Bernstein told IBD.
AbbVie, Bristol-Myers and Gilead are all expected to report final study details at the International Liver Congress, meeting in London April 9-13. Company officials are keeping mum on which studies will be presented, but abstracts will go online March 24. (Late-breaking abstracts, which appear right before the conference, often have the hottest data.) Next-Generation Regimes
Further down the road, even more drugs are on the way.
AbbVie and partner Enanta Pharmaceuticals (ENTA) are already working on a next-generation regime that will treat more genotypes and also be simpler to take. (A common criticism of the 3D is that it's more complicated than Gilead's promised pill-a-day routine.) Earlier this month, Merck (MRK) also reported very strong phase two results for its two-drug combo for genotype 1 patients, some of whom were co-infected with HIV. Johnson & Johnson (JNJ) last October acquired three HCV drugs from GlaxoSmithKline (GSK), which it hopes to combine with its already approved Olysio into an all-oral regimen.
Sovaldi, meanwhile, has lately been under pressure both for its $1,000-a-pill price tag and concerns about sustainability — after all, one outcome of finding a curative drug is that the patient population eventually shrinks.
Still, Morningstar analyst Damien Conover says Gilead has a first-mover advantage and such strong trial data that it likely will be the biggest player for the indefinite future.
"I think we'll have Gilead representing 50% of the hep C market," he told IBD. "AbbVie will take the lion's share of what's remaining."