On 7 July, GlaxoSmithKline (GSK) released the results for its Phase IIb / III randomised trial for the investigational human immunodeficiency virus (HIV) prevention drug cabotegravir as a comparator to Gilead’s currently reigning pre-exposure prophylaxis, Truvada (emtricitabine / tenofovir disoproxil fumarate). Although cabotegravir may have superior effects of over Truvada, GlobalData believes that cabotegravir’s potential high cost and administration via injection may be potential issues for most HIV-risk individuals.
GSK’s Phase IIb / III (HPTN 083) trial showed that cabotegravir, a drug used for pre-exposure prophylaxis (PrEP), had superior efficacy over Truvada. The trial identified that there were only 0.41% HIV incident cases in the cabotegravir arm compared to 1.22% in the Truvada arm, a decrease of 66%. Due to the superior efficacy of cabotegravir, the trial was stopped early after a review was conducted by an independent data monitoring panel.
Cabotegravir is an injectable given every two months in the physician’s clinic, while Truvada is an oral tablet administered daily. Key opinion leaders (KOLs) interviewed by GlobalData have concerns over individuals wanting to go into the clinic to get a long and painful injection. As such, adherence may be an issue with cabotegravir, but an oral tablet can be taken from the comfort of the patient’s home without any painful site reactions.
Additionally, Truvada costs $1,780 for a 30-day dosing regimen in the US, while in other parts of the world generic versions are available for approximately $40 for a 30-day supply. In the US, the generic version will be available as of September 2020, where it may cost $40. Therefore, due to the lower price, GlobalData believes that individuals may prefer to take Truvada over the expensive injectable cabotegravir as insurance policies may not reimburse the injection or it may not be funded through charitable organisations such as the Ryan White HIV / AIDS program.
Therefore, although cabotegravir was shown to have superior effects over Truvada, GlobalData believes patients may still prefer Truvada due to the ease of administration and the likely lower cost.