GSK is charting an optimistic course for its HIV business, buoyed by the success of its long-acting antiretroviral therapy, Cabenuva. Deborah Waterhouse, the CEO of GSK’s specialized HIV subsidiary, ViiV Healthcare, has projected that the company’s HIV product sales will surge to £7 billion ($8.5 billion) by 2026.
This ambitious forecast reflects GSK’s expectation of an average annual sales growth of 6% to 8% in its HIV franchise over the next five years leading up to 2026. This marks a notable upturn from the mid-single-digit percentage growth target set by GSK for ViiV back in 2021.
In the previous year, GSK reported £5.7 billion in HIV drug sales, reflecting a substantial 12% increase from 2021 when measured at constant currencies.
While GSK now officially projects £7 billion in sales by 2026, it’s worth noting that this figure had already been predicted by ODDO BHF analysts in the preceding year.
The driving force behind this optimistic outlook is the exceptional performance of the long-acting HIV treatment, Cabenuva, as emphasized by Waterhouse during a press call. Approved by the FDA in January 2021, Cabenuva offers patients the flexibility of being administered every one or two months. In the first half of 2023 alone, the drug generated £303 million in revenue.
Cabenuva’s success can be attributed to its long-acting nature, which provides patients with the freedom to avoid the daily regimen associated with traditional oral medications.
GSK anticipates that by 2026, long-acting regimens will contribute significantly, making up approximately a third of GSK’s HIV revenue. These regimens will play a pivotal role in sustaining GSK’s HIV business, particularly as the older-generation dolutegravir (Tivicay) approaches the end of its patent protection period toward the close of the decade.
In April 2028, Dolutegravir’s core composition patent is set to expire in the US, while the formulation patents associated with combination therapies Dovato and Juluca are slated to expire in 2029 and 2030, respectively, as per Waterhouse’s disclosure. However, it’s essential to note that daily pills, such as Gilead Sciences’ widely used Biktarvy, remain a cornerstone of HIV treatment. Waterhouse acknowledges that, for some patients, the requirement to visit a clinic every two months for Cabenuva treatment may prove cumbersome.
Consequently, GSK is diligently working on the development of ultra-long-acting drugs and self-administered options to enhance convenience for patients. The company has now provided updated estimates for the timeline of bringing these products to market.
GSK’s objective is to designate a leading self-administered long-acting HIV candidate by the following year and seeks approval by 2030. Additionally, the company plans to incorporate cabotegravir, a key component of Cabenuva, into a once-every-four-month treatment by 2027, with the ultimate goal of extending the dosing interval to twice yearly by 2030.
It’s worth noting that this adjusted timeline represents a delay from GSK’s original plan, which was outlined in 2021. The delay is attributed to the complexity of developing the self-administered product, as GSK needs to devise a suitable delivery device. For this therapy, GSK is initially targeting a dosing interval of around two to three months, according to Kimberly Smith, M.D., ViiV’s R&D chief.
Three critical factors will determine the regimen GSK advances: the appropriate dosing interval, tolerability, and the ability to fit into an autoinjector. GSK has several options at its disposal, including reformulating cabotegravir, a collaboration with Shionogi on a third-generation integrase inhibitor (VH184) with long-acting potential, and a newer integrase inhibitor known as VH310.
GSK emphasizes the importance of integrase inhibitors, not just because of its multiple options but also because of their demonstrated resistance compared to available capsid inhibitors, as elucidated by Smith.
Regarding ultra-long-acting treatments, GSK has identified cabotegravir as one component but has yet to finalize the regimen. Smith mentions N6LS, a broadly neutralizing antibody licensed from the NIH, as a potential combination partner. The drug entered phase 2b testing in August, and GSK is exploring the use of partner Halozyme’s drug delivery technology to create a subcutaneous formulation.
Smith suggests that self-administered and ultra-long-acting therapies may cater to different patient populations. Ultra-long-acting regimens align with the typical clinic visit frequency for disease monitoring, while self-administered options may appeal to individuals comfortable managing their medication at home.
In essence, the longer the interval between clinic-administered drugs, the higher the expectations for self-administered options, as Smith pointed out. This multifaceted approach by GSK underscores its commitment to advancing HIV treatment options and improving patient experiences.
