The primary efficacy and safety outcomes of interest were HIV infection and occurrence of a grade ≥ 2 adverse drug reaction, respectively. HIV seroconversion occurred in 13 of 2282 (0.57%) patients in the CAB-LA group and 39 of 2284 (1.7%) patients in the TDF-FTC group (hazard ratio = 0.34; 95% CI, 0.18-0.62). The rate of severe adverse drug reactions was similar between groups. The study was stopped early due to the superiority of CAB-LA.
WHAT’S NEW
Demonstrated superiority of injectable vs oral PrEP
The results of this study could have a monumental impact on the spread of HIV. Since adherence is a known limitation of daily oral PrEP, a long-acting injectable is an intriguing option. The 8-week period between injections offers convenience, allowing primary care physicians (PCPs) to schedule their patients in advance. And because every injection is administered in the office, this option would help PCPs track adherence. Witnessed adherence to the medication, and its demonstrated superiority, could have a significant effect on HIV prevention.
The limited serious adverse effects reported by both groups may ease some PCPs’ hesitation to prescribe CAB-LA.
CAVEATS
More injection-site reactions (but little impact on adherence)
Notably, 81.4% of patients in the CAB-LA group had injection-site reactions vs 31.3% in the TDF-FTC group. However, only 2.4% of patients in the CAB-LA group opted to stop receiving the injections because of these reactions.
Standard PrEP reduces the risk for HIV acquisition from IV drug use by 74%.2 However, because IV drug use was an exclusion criterion in this study, future research will need to assess CAB-LA’s effectiveness in that population.
CHALLENGES TO IMPLEMENTATION
Price and storage requirementsof CAB-LA may create issues
CAB-LA is expensive, costing more than $25,000 per year—significantly outpricing TDF-FTC, which costs approximately $8300 per year.3 Insurance coverage for PrEP, including CAB-LA, varies widely. Given the superiority reflected in this study, more efforts should be made to lower the cost of the medication.
Another hurdle for CAB-LA is that it requires refrigeration for storage. Although likely not an issue in most of the United States, it will make adoption of this method difficult in other parts of the world.
