Gilead Sciences' (NASDAQ:GILD) sofosbuvir with Johnson & Johnson (NYSE:JNJ) and Medivir's simeprevir are a match made in heaven. So far, the combination has cleared hepatitis C virus from patients no matter how it's administered.
Interim data from a phase 2a showed 100% of patients were free from virus 12 weeks after treatment. The trial was divided into four treatment groups: Patients were treated for either 12 or 24 weeks with either the just the two experimental drugs or adding an approved generic called ribavirin to the mix.
The results are especially impressive because these patients had already failed to respond to treatment with a pegylated interferon -- Roche's Pegasys or Merck's Pegintron -- and ribavirin. Retreatment with those drugs and adding Vertex Pharmaceuticals' (NASDAQ:VRTX) new drug Incivek only results in cures about 32% of the time for patients that failed a first treatment. More importantly, unlike Incivek, the sofosbuvir-simeprevir combination doesn't require pegylated interferons that produce nasty side effects.
We have to be careful drawing too much from the data. The trial is scheduled to enroll 80 patients, but only 10 have reached 12 weeks post treatment. Nineteen patients have been treated completely, and all of them were free of virus at the end of treatment. But the virus can be knocked below the limits of detection for hepatitis C tests but not eradicated by drugs, and then relapse and build back up after the treatment ends. Being free from virus 12 weeks after treatment is essentially a cure.
Despite the awesome data, this combo therapy isn't likely to ever see the pharmacy, at least not in a single pill. The deal to run a clinical trial testing the two drugs was established between Johnson & Johnson and Pharmasset, before Gilead bought the biotech.
Gilead has made it abundantly clear that it's planning on pushing on with a combination of sofosbuvir and drugs it has developed in-house. It shunned Bristol-Myers Squibb (NYSE:BMY), which also has a hepatitis C drug that produced solid data with sofosbuvir. I doubt Gilead will be interested in teaming up further on a sofosbuvir-simeprevir combination.
Fortunately for Johnson & Johnson and Medivir, simeprevir is being tested with additional hepatitis-C drugs, including Vertex's VX-135, Idenix Pharmaceuticals' (NASDAQ: IDIX) IDX719 and Bristol-Myers' daclatasvir. If any of those combinations can hit 100% efficacy and the partners can agree to produce a convenient combination pill, they should have a shot at taking on Gilead.