Advera: AbbVie's Viekira Pak riskier than Gilead's Harvoni for hep C

Viekira--Courtesy of AbbVie

AbbVie ($ABBV) is facing bad news for its hep C powerhouse Viekira Pak as it dukes it out for market share with Gilead Sciences ($GILD) in the hep C market. Healthcare informatics firm Advera Health Analytics looked at new side effect reports on hep C treatments, including those for Gilead's Sovaldi and Harvoni, and AbbVie's Viekira Pak, and found that AbbVie's drug was the riskiest option among the three meds.

In its analysis, Advera saw that Viekira Pak's RxCost per prescription--a proprietary calculation based on the direct cost of adverse events--shot up 200% to $151. And the drug's RxScore, a number that demonstrates its safety, jumped 8 points to 73.93, making it the most likely of the three meds to trigger side effects. For comparison's sake, Harvoni had a 32% drop in RxCost to $60.24, based on the new side-effect reports, and an RxScore of 68.98--the lowest of the three treatments, according to Advera's report.

Back in May, Advera examined post-marketing side effects reports for hep C meds to see which drugs had the safest profiles, and found that Gilead Sciences' Sovaldi and Harvoni showed advantages over older treatments, including Merck's ($MRK) Victrelis and Vertex Pharmaceuticals' ($VRTX) Incivek.

Advera's Keith Hoffman

"Everyone assumes that a newer generation is safe, and oftentimes, it's not. But in this case it's true," Keith Hoffman, VP of scientific affairs at Advera, told FiercePharmaMarketing at the time. "Some of the drugs in the older generation of hep C meds are only a couple years old, but we're already seeing an incredible shift in the efficacy and safety of these drugs."

But Advera left Viekira Pak out of its May analysis because there wasn't enough post-marketing data for the drug at the time. Still, the latest numbers confirm the company's previous predictions about Viekira Pak, as Hoffman said that Advera was "not optimistic" that AbbVie drug's safety profile would top Harvoni's or Sovaldi's. Viekira Pak has four active ingredients and a long list of side effects on its FDA approved label, Hoffman pointed out. Plus, regulators already caution against using the med in hep C patients with severe liver impairment or who are taking other drugs.

AbbVie has stood by its med's safety. An "analysis of Viekira Pak's implied safety on the sole basis of a partial label reference without noting the medicine's rigorous clinical program is superficial and not clinically relevant," the company told FiercePharmaMarketing in an email in May. "Viekira Pak's safety assessment was based on data from the large clinical trial program, and since clinical trials are conducted under varying conditions, adverse reaction rates observed in Viekira Park trials cannot be directly compared to rates in the clinical trials of another drug."

The company will continue to evaluate patient response to Viekira Pak through a post-marketing surveillance program, gathering safety data to analyze the drug among a broader GT1 patient population, it added.

AbbVie has not yet commented for the story at press time.

- read the Advera Health Analytics report (reg. req.)

Special Reports: The new drug approvals of 2014 - Harvoni - Viekira Pak | The new drug approvals of 2013 - Sovaldi - Gilead