REGULATORY UPDATE: 2-Year Medication Deferral Planned for Injectable Cabotegravir

August 19, 2022

An upcoming AABB Association Bulletin will recommend a two-year medication deferral for donors who have received an injection of cabotegravir, leaders from the AABB Transfusion Transmitted Diseases (TTD) Committee and Donor History Task Force (DHTF) announced yesterday. Future versions of the AABB Donor History Questionnaire (DHQ) will also include donor eligibility criteria for this medication deferral.

In December 2021, the Food and Drug Administration approved cabotegravir (Apretude, ViiV Healthcare), the first long-acting, injectable medication for the prevention of HIV infection, also known as pre-exposure prophylaxis (PrEP). While the approval marks an important step forward for HIV prevention efforts, it also presents new considerations for blood collectors.

AABB’s volunteer leaders hosted a Hot Topic discussion to explore the history of PrEP medications, the efficacy and contributions of this important public health initiative, and impact of cabotegravir for PrEP, and how blood donor screening and testing will change in response to these developments.

Jed B. Gorlin, MD, MBA, vice president and medical director, Innovative Blood Resources, and chair of the AABB TTD Committee, kicked off the program with an overview of PrEP. Prior to the approval of cabotegravir, PrEP was available only as a daily oral medication (tenofovir and emtricitabine). Because PrEP can inhibit the ability of antibody and NAT testing to detect exposure to/carriage of HIV, AABB instituted a three-month deferral for this therapy in 2020.

Gorlin shared that, unlike oral versions of PrEP, cabotegravir may remain in the systemic circulation of individuals up to 12 months or longer. Due to pharmacokinetics of cabotegravir, its long-acting properties and the drug’s potential effect on donor testing, the TTD Committee sent an inquiry to FDA, the Center for Biologics Evaluation and Research and the Office of Blood Research and Review shortly after cabotegravir’s approval. In its response to AABB, FDA agreed with an “approach to use a 3-month deferral for oral PrEP and a longer deferral period for injectable PrEP.”

Brian Custer, PhD, MPH, director of Vitalant Research Institute, senior vice president of Research and Scientific Programs at Vitalant, and an adjunct professor in the Department of Laboratory Medicine at the University of California San Francisco, reviewed clinical trial data examining the efficacy of cabotegravir compared with oral PrEP, discussed the pharmacokinetics of cabotegravir, and described two examples of HIV infection among persons using cabotegravir. 

These studies suggested that cabotegravir use was associated with a 69% decrease in the risk of HIV infection among transgender women and cisgender men who have sex with men, and a 90% decrease in the risk of HIV infection among cisgender women. According to Custer, this may be the result of cabotegravir’s efficacy (and that of other integrase inhibitors) or better adherence to the 2-month injection cycle compared with daily pill use.

Custer also reviewed data from a study of cabotegravir’s tail-phase safety. These data illustrated the distribution of participant plasma cabotegravir concentrations aggregated at 12‐week intervals after the final injection. While the majority of patients had non-detectable levels of cabotegravir by week 72, some patients had detectable levels. The data also suggested that females and those with a higher body mass index had longer tail phases.  

Mary Townsend, MD, senior medical director, National Office, Vitalant, and chair of the DHTF, closed the presentations with a preview of changes that blood collectors can expect to see in the Association Bulletin and the upcoming Donor History Questionnaire, version 3.0, which the AABB plans to submit to FDA in September. If approved by FDA, v3.0 will distinguish between oral and injectable PrEP. It will also include updates to flowcharts, donor education materials and the medication deferral list that reflect these changes. The DHTF will provide a toolkit to support the extensive process change efforts required at implementation.

The AABB Board of Directors will be reviewing the draft Association Bulletin in the coming days, which AABB plans to release later this month. AABB is also preparing a question-and-answer resource that blood collectors can use to educate staff, donors and the public about PrEP and about changes to donor eligibility.

Members with questions may contact