It’s what many people with H.I.V. have long awaited: monthly injections to keep the virus in check, instead of the three drugs daily they now must take.
The Food and Drug Administration on Thursday approved a combination of two monthly shots for treatment of H.I.V. in patients in stable condition. The treatment is called Cabenuva.
One of the two shots also has been shown to be as effective at preventing H.I.V. infection as a pill taken daily, a treatment strategy called pre-exposure prophylaxis, or PrEP. But the approval on Thursday covers only Cabenuva’s use as a treatment.
Many people struggle to take the pills they need every day, for a variety of reasons. The consequences for people with H.I.V. can be significant, because missed pills give the virus opportunities to become resistant to the medications.
And then there is the stigma of daily pill use, which is both societal and psychological, said Dr. Tom Giordano, chief of infectious diseases at Baylor College of Medicine in Houston, who was not involved in the trials.
Nine in 10 people in a trial of Cabenuva said they preferred the monthly injections to taking a pill every day. “You get your shot and forget about it till the next month,” Dr. Giordano said. “That’s great, and will help people who don’t want the reminder of stigma or taking pills every day.”
Cabenuva is a combination of two drugs: cabotegravir and rilpivirine. Each is injected separately at the same appointment. In clinical trials, the treatment suppressed H.I.V. to undetectable levels for two years.
A later trial found that the treatment is just as effective when administered once every two months, instead of monthly. The F.D.A. approval covers the drug’s use every month, but a spokeswoman for ViiV Healthcare, which manufactures one of the drugs in the combination, said the company was planning to apply for approval for bimonthly administration.
Experts said that although the approval was good news, it was unclear whether monthly injections would turn out to be practical outside clinical trials.
In the trials, the drug was tested in people who took daily pills and had undetectable H.I.V. levels — just one slice of those with H.I.V. “The problem is the drug is approved on studies that included people who are already doing well,” Dr. Giordano said. “But we don’t have any data on how to better help people who are not stable and not doing well.”
A trial to test the shots in people who are unable to take their medications regularly is underway.
People with H.I.V. stop taking their medications for any number of reasons. They may lose their insurance, get dropped from medication assistance programs because of missing paperwork, have problems with substance use or mental health, or may end up in jail.
In people who stop taking the H.I.V. pills, the odds that the virus they carry will become drug-resistant are not high. But the injectables leave a “long tail” of antiviral drugs that persist in the body at low levels even if doses are missed. That may provide the right conditions for the virus to adapt and become resistant.
“Low drug levels are going to persist for a long time,” Dr. Giordano said. “That’s the benefit and the Achilles’ heel of a long-tail drug.”
In the two-year trial, 10 people developed resistance to the combination. But some of them might have been resistant because they had previously taken other related drugs.
To inject the drugs regularly, doctors providing the treatment will need to see H.I.V. patients far more often than they now do — a requirement made even more difficult by the pandemic.
Cost is another concern. Doses of the combination will cost roughly $4,000 per month, plus $6,000 for the initial dose, according to a spokeswoman for ViiV Healthcare. Some people with H.I.V. may not be able to afford the treatment, said Mark Harrington, who heads Treatment Action Group, an advocacy organization.
Cabenuva may carry side effects that become apparent only after the drug is in wide use. But the treatment has been approved in the European Union and Canada and seems to be safe so far, Mr. Harrington said.
The injections are not trivial. The required needles are wider and longer than those used for a flu shot, for example, and the barrels hold several times the volume.
“Women patients really, really liked this,” said Dr. Susan Swindells, one of the trial investigators and a physician at the University of Nebraska Medical Center in Omaha. Women participating in the trial, in particular, liked the injections because the competing demands on their time and attention — and the possible stigma — made it harder for them to take a daily pill, she said.
Greater privacy is also a boon for anyone who does not wish to reveal their H.I.V. status. Steven Harris, 41, a participant in one of the trials, worked as an international trade lawyer and had often traveled to countries that did not allow entry to people with H.I.V. “I had this fear of being stopped at customs,” he said.
After he started receiving the injections, Mr. Harris disclosed his H.I.V. status to his family. The long-acting combination “has been really cool,” he said last year. “It’s liberated me both physically from the pill bottle and also psychologically — and that’s the part that I hadn’t really expected.”