- The Food and Drug Administration rejected a two-drug HIV combination regimen submitted by ViiV Healthcare, a drug developer majority-owned by GlaxoSmithKline, the British pharma said Saturday.
- GSK said the Complete Response Letter stemmed from manufacturing concerns unrelated to the drug's safety. "There have been no reported safety issues related to [Chemistry Manufacturing and Controls] and there is no change to the safety profile of the products used in clinical trials to date," the pharma said in its Dec. 23 statement.
- The combination, which pairs ViiV's cabotegravir with Jonhson & Johnson's rilpivirine, would have become the third doublet from GSK after the drugmaker's marketed Dovato and Juluca. Both of those drugs, however, are taken as once-daily tablets, while cabotegravir and rilpivirine are designed to deliver viral suppression via once-monthly shots.
In an HIV market dominated by triplet regimens sold by Gilead, GSK was hoping the combination of cabotegravir and rilpivirine could be an attractive, longer-lasting alternative.
The drug pairing stems from a collaboration between ViiV and Johnson & Johnson's Janssen unit, which developed rilpivirine. In a statement, Brian Woodfall, Janssen's head of infectious diseases development, noted the drugmakers will work with the FDA to find a path to U.S. approval, a commitment GSK echoed. No timeline was indicated for resubmission to the agency.
In April, ViiV received approval for Dovato, a combo of dolutegravir and lamivudine. That therapy has brought in about $30 million in its first six months on market while Juluca, which uses rilpivirine, earned GSK roughly $330 million this year.
The two-drug regimens are meant to offset flat or declining sales for GSK's mainstay triple combinations, which brought in $4 billion through the first nine months of 2019.
But that pales in comparison to Gilead, which posted nearly $12 billion in sales from HIV products from January through September.
Most of Gilead's recent success has come from Biktarvy, a triplet therapy that was approved by the FDA in February 2018 and has already become the company's best-selling drug. Through the first nine months of 2019, Biktarvy exceeded $3.1 billion in worldwide sales.
While Gilead has retained its market dominance, ViiV leaders have said they believe patients would prefer a regimen with fewer drugs but maintained antiviral activity. And if GSK can fix up whatever problems caused the FDA to reject this two-drug regimen, it could be an even more attractive option for patients with HIV than Dovato.
Dovato is a once-daily pill, while this filing for cabotegravir and rilpivirine is for once-a-month administration.
GSK has also released positive Phase 3 study results showing an injection every eight weeks was non-inferior to the monthly treatment. That trial will be the basis of a planned supplemental filing, previously anticipated in early 2020, but that timeline may be pushed back with Saturday's rejection disclosure.
ViiV was created a decade ago by GlaxoSmithKline. Pfizer and Shionogi hold minority stakes in the subsidiary.