Riding on the growth of long-acting antiretroviral therapy Cabenuva, GSK is laying out a more optimistic vision for its overall HIV business.
GSK projects its HIV products will reach £7 billion pounds sterling ($8.5 billion) in sales by 2026, Deborah Waterhouse, CEO of GSK’s specialist HIV company ViiV Healthcare, said Thursday.
The British pharma company expects the HIV franchise will grow sales by an average of 6% to 8% annually during the five years leading up to 2026. That was a step up from the mid-single-digit percentage annual growth target that GSK laid out for ViiV back in 2021.
Last year, GSK recorded 5.7 billion pounds in HIV drug sales, a 12% increase from 2021 at constant currencies.
While the 7 billion pound forecast is new from GSK itself, the number was already raised by ODDO BHF analysts last year.
Strong performance of long-acting HIV regimen Cabenuva fueled the new guidance, Waterhouse told reporters during a press call. Approved by the FDA in January 2021, Cabenuva can be given every one or two months. In the first half of 2023, the drug brought in 303 million pounds.
Cabenuva is doing well because long-acting drugs—compared with traditional daily orals—give patients a level of freedom so they don’t fear missing daily doses, Waterhouse said.
The long-acting regimens will make up about a third of GSK’s HIV revenue by 2026, Waterhouse said. They will help GSK when its older-generation dolutegravir (Tivicay) loses patent protection toward the end of the decade.
Dolutegravir’s core composition patent expires in April 2028 in the U.S., while its formulation patents related to the combination therapies Dovato and Juluca expire in 2029 and 2030, respectively, according to Waterhouse.
Still, daily pills such as Gilead Sciences’ megablockbuster Biktarvy remain the mainstay of HIV treatment. Waterhouse has previously acknowledged that for some patients, having to go to a clinic every two months to receive Cabenuva can be too cumbersome.
That’s why GSK has been working to develop ultra-long-acting drugs and self-administered options. The company on Thursday provided new estimates as to when it expects to bring such products to the market.
GSK aims to select a lead self-administered long-acting HIV candidate next year and hopes to win an approval by 2030.
In addition, the company plans to incorporate cabotegravir—a component in Cabenuva—into a once-every-four-month treatment by 2027, with a goal to further extend the dosing interval to twice yearly by 2030.
The new timeline for the self-administered product marks a delay from GSK’s original plan, shared in 2021.
The self-administered version takes longer to develop because GSK needs to find a proper device to deliver the drug, ViiV’s R&D chief Kimberly Smith, M.D., told Fierce Pharma during an interview. For this therapy, GSK is initially targeting a dosing interval of around two to three months, she said.
Three factors will determine which regimen GSK will advance, Smith said. Besides sufficient dosing interval and tolerability, the drug must come in the right volume to fit into an autoinjector.
GSK has several options to choose from. Besides reformulating cabotegravir, the company has a Shionogi-partnered third-generation integrase inhibitor coded VH184, which also has long-acting potential and the ability to tackle multiple HIV mutations, plus a newer integrase inhibitor called VH310.
“We do believe that the regimen should be built on a foundation of integrase inhibitors,” Smith said during the press call.
GSK’s approach to long-acting regimens is different from rival Gilead’s. Gilead has Sunlenca, a capsid inhibitor that can be given every six months. The drug is approved to be used in combination with other therapies to treat patients whose HIV isn’t controlled by existing treatments.
GSK is stressing the importance of integrase inhibitors not because it happens to have several options in the class, but also because they have shown a high barrier to resistance compared with available capsid inhibitors, Smith explained to Fierce Pharma.
As for the ultra-long-acting treatments, GSK has set cabotegravir as one of the components but has yet to determine the final regimen. Smith mentioned N6LS, a broadly neutralizing antibody that GSK licensed from the NIH, as a potential combination partner. The drug entered phase 2b testing in August, and GSK is exploring using its partner Halozyme’s drug delivery technology to make it a subcutaneous formulation.
Smith suggested that the self-administered and ultra-long-acting therapies might target different patient populations. The dosing interval for ultra-long-acting matches the frequency a patient typically visits the clinic to monitor the disease. Combining the two together allows the doctor to directly observe treatment.
By comparison, the self-administered version could appeal to people who are comfortable having their drugs in their house.
Eventually, the longer the interval of the clinic-administered drug, the higher the bar for the self-administered version, Smith argued.
“If you’ve only got to come into the clinic three times a year, do you want the hassle of having it at home?” Smith said. “It’s got to be a really well-tolerated, easy-to-deliver regimen.”