ViiV Halts HIV Prevention Trial Early; Data Shows Asset is 69% More Effective Than Standard of Care


ViiV Healthcare halted an HIV study early after an interim data analysis showed the investigational prevention medication cabotegravir was found to be 69% more effective at preventing the transfer of the disease compared to standard of care. The results set up the potential for regulatory approval.

ViiV, which is an HIV-specialized company owned by GlaxoSmithKline, Pfizer and Shinogi Limited, said the interim analysis of the cabotegravir study hit the primary objective of non-inferiority to the oral combination of emtricitabine/tenofovir disoproxil fumarate 200 mg and 300 mg tablets. Noy only did cabotegravir hit the non-inferiority mark, the treatment results showed a superiority in favor of the ViiV medication. The study found the medication was 69% more effective in preventing transfer of HIV between men engaging in sexual intercourse with other men and transgender women who have sex with men, the company said. The HIV Prevention Trials Network 083 study included 4,600 participants across more than 40 sites in North and South America, Asia, and Africa and is one of the first trials to directly compare two active prevention agents. Two-thirds of study participants were under 30 years of age, and 12% were transgender women. Half of the participants in the United States identified as black or African American.

In a planned interim review, ViiV said the independent Data and Safety Monitoring Board (DSMB) found the study data clearly indicated that long-acting injectable cabotegravir was highly effective at preventing HIV in the study population. In the trial, 50 people did acquire HIV. Of those, 12 were receiving the ViiV medication, which translates into an HIV incidence rate of .38% for cabotegravir and 1.21% for standard-of-care. Following the interim review, the DSMB recommended halting the trial and publishing the results. Participants who were in the FTC/TDF arm will be offered CAB LA and participants in the CAB LA arm will continue to receive it. Participants who do not want to receive CAB LA will be offered FTC/TDF until the end of the originally planned blinded component of the study, ViiV noted in its announcement. Safety was similar in both groups.

Detailed results from HPTN 083 will be presented at an upcoming scientific meeting and ViiV Healthcare plans to use the data from HPTN 083 for future regulatory submissions.

Kimberly Smith, head of research & development at ViiV Healthcare, said the results of the trial demonstrated that cabotegravir given every two-months to patients can successfully reduce HIV acquisition in homosexual men and transgender women.

“We are thrilled with the results not only because of the high efficacy of cabotegravir but also because we have demonstrated high efficacy in a study that adequately represents some of the populations most disproportionately impacted by HIV -- black MSM in the US, young MSM (men who engage in intercourse with other men) globally and transgender women,” Smith said in a statement.

The positive results from the analysis were a shot in the arm for ViiV, which received a Complete Response Letter from the U.S. Food and Drug Administration in December for its combination treatment of cabotegravir and rilpivirine as a long-acting regimen for treatment of HIV-1 infection in virologically suppressed adults. The company sought approval based on non-inferiority data announced in August.

With the 083 study halted, eyes are now on the 084 companion study, which began one year after 083. The 084 study is expected to provide data on HIV transfer among females. More than 3,000 sexually active women in seven African countries have enrolled in HPTN 084.

“New options are needed for HIV prevention that offer an effective alternative to daily oral PrEP. If approved, this long-acting injectable has the potential to be a game-changer for HIV prevention by reducing the frequency of dosing from 365 days to six times per year,” Smith said.

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