An end to daily pills could finally be on the horizon for HIV patients. A new trial has found that an injection of long-acting forms of antiviral drugs work just as well as a daily oral regimen of three therapies. That is, the cocktail of pills taken by mouth were no more effective at suppressing the rate of viral replication than the experimental jab.
The drugs on trial are injectable preps of two treatments that attack HIV at different stages of its life cycle. Rilpivirine, created by pharma company Janssen, is an approved once-daily pill that stops HIV’s genome from being copied into a form that can successfully be inserted, or integrated, into a person’s DNA, a prerequisite for replication. Cabotegravir, developed by ViiV Healthcare, prevents that latter phase of integration, but it’s still being evaluated as both a daily pill and an injectable formulation.
The 96-week trial, LATTE 2, is a collaborative effort by those two pharmaceutical companies, and follows on from an earlier investigation, LATTE, which concluded that daily doses of cabotegravir and rilpivirine exerted similar antiviral effects as a widely used trio of oral drugs. For the new investigation, due to be presented at a conference soon, researchers compared the efficacy of either four or eight weekly doses of injectable cabotegravir and rilpivirine with oral pills of the former plus two more drugs.
More specifically, researchers were looking for a defined viral suppression rate, which was less than 50 copies of viral genetic material, in this case RNA, per milliliter of blood. There were 309 adults enrolled in the study, who were randomly assigned into the three groups. At 32 weeks, 95 percent of those receiving the injection every eight weeks achieved this suppression rate, as did 94 percent of those receiving doses every four weeks, which was comparable to the figure on the oral regimen (91 percent).
Among those given the four weekly jabs, 5 percent had side effects that led them to withdraw from the study, compared to 2 percent in both of the other groups. The most common of these events was pain at the injection site, and two pulled out because they were intolerant of the injection.
If follow-up investigations provide similarly positive results, the implications could be significant. No longer are the dark days where patients are popping tens of pills daily, but a drop from a daily pill to a monthly or even less frequent injection would still be of huge benefit to patients. Reliably taking oral pills every day is necessary to keep viral replication at bay; poor compliance can jeopardize that and consequently increase risk of transmission.
“The possibility of a long-acting injectable has great potential to improve people’s quality of life, particularly for those who struggle with adherence to their medication,” Justin Harbottle, program officer for quality and engagement at Terrence Higgins Trust, a U.K. HIV and sexual health charity, told IFLScience. “Hopefully the cost of the new injectable treatment won’t inhibit them from being available to the people who would benefit from them the most.”
But this injection isn’t a magic wand: It still can’t cure patients, and it has some drawbacks. As Bloomberg points out, it needs to be kept refrigerated, which has implications for many rural areas in developing nations, and it also isn’t suitable for self-administration at this stage, meaning trained professionals would have to inject it each time.