ViiV Healthcare, the global specialist HIV company majority owned by GlaxoSmithKline plc, with Pfizer Inc. and Shionogi Limited as shareholders, announced that the US Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation for long-acting, injectable cabotegravir for HIV pre-exposure prophylaxis (PrEP).
The Breakthrough Therapy Designation was based on efficacy and safety results from HPTN 083, a phase IIb/III randomised, multicentre, double-blind, clinical trial that compared long-acting, injectable cabotegravir to daily oral emtricitabine/tenofovir disoproxil fumarate 200 mg and 300 mg (FTC/TDF) for HIV prevention among men who have sex with men and transgender women who have sex with men.
Final analysis of HPTN 083 showed the superiority of long-acting cabotegravir, which was 66% more effective at preventing HIV when compared to daily oral FTC/TDF tablets. This translated to an HIV incidence rate of 0.41% in the cabotegravir group (95% confidence interval [CI] 0.22%-0.69%) and 1.22% in the FTC/TDF group (95% CI 0.87%-1.67%) in a study population of 4,566. The results of HPTN 083 were presented at the 23rd International AIDS Conference (AIDS 2020) in July. The blinded phase of HPTN 084, a partner HIV prevention study in sub-Saharan African women, was stopped earlier this month based upon recommendation of the independent data safety monitoring board (DSMB) following demonstration that long-acting cabotegravir was superior to oral FTC/TDF tablets. ViiV Healthcare plans to use the data from both HPTN studies for future regulatory submissions.
The Breakthrough Therapy Designation is intended to facilitate the development and expedite the review of drugs that address serious or life-threatening medical conditions. The criteria for Breakthrough Therapy Designation require preliminary clinical evidence that demonstrates a drug may have substantial improvement on at least one clinically significant endpoint over available therapies. The Breakthrough Therapy Designation means closer and more frequent collaboration with the FDA to discuss the drug’s development plan and ensure collection of appropriate data needed to support its approval.
Kimberly Smith, M.D., MPH, Head of Research & Development at ViiV Healthcare, said: “New medicines that decrease the risk of HIV acquisition in at-risk populations are an essential tool to help us end the global HIV epidemic. Our data from the HPTN 083 and 084 studies show that long-acting cabotegravir is superior to daily oral FTC/TDF tablets for HIV prevention. We are looking forward to working closely with the FDA to make this prevention option available to people at risk of acquiring HIV.”
HIV continues to be a global public health crisis, with an estimated 38 million people living with HIV and 1.7 million new cases of HIV at the end of 2019. Advancements in research and development have identified new approaches to HIV treatment and prevention, such as long-acting cabotegravir. Long-acting cabotegravir has not been approved or licensed anywhere in the world for use in HIV prevention.