Descovy for PrEP

The most common adverse event is diarrhea, observed in up to 5% of individuals given Descovy in the large DISCOVER study that led to FDA approval of Descovy for PrEP. There was also nausea (4%) and headache, fatigue, and abdominal pain (2% each). Check for hepatitis B virus (HBV) before taking Descovy and vaccinate against it if appropriate. If Descovy is discontinued abruptly in people with hepatitis B virus, flare-up of hepatitis may occur—talk to your provider before discontinuing. Drug resistance to HIV therapy may develop if people going on Descovy for PrEP unknowingly already have HIV, or if infection occurs after starting PrEP. However, drug resistance was rare in the extremely few individuals who acquired HIV during the DISCOVER trial (seven out of 2,670 persons on Descovy and 15 out of 2,665 on Truvada at the primary analysis). All were in the Truvada arm and all were in those with baseline HIV infections. As with previous PrEP studies, DISCOVER found the effectiveness of Descovy for PrEP was related to drug adherence—taking Descovy daily for PrEP as prescribed. The TAF component in Descovy is associated with relatively decreased risk for toxicity to the kidneys and bones (such as decreases in estimated glomerular filtration rate, or eGFR, and bone mineral density, or BMD) when compared to TDF in Truvada. Kidney function (including creatinine clearance, or CrCl) should be monitored while taking Descovy for PrEP. Recommended monitoring also includes STI screening. When comparing TDF versus TAF, bone changes may be of greater concern for young people whose bone structure is still growing and for older individuals who may be becoming frail. Kidney changes may be of greater concern for individuals who have preexisting kidney problems or older individuals at risk of developing kidney problems. Stigma remains a significant concern of HIV prevention, especially PrEP. When taken for HIV treatment, TAF has been associated with weight gain; see Descovy page.

Do not take with any other HIV or HBV drugs (including Vemlidy, or TAF) when using Descovy for PrEP. Avoid taking Descovy with drugs that negatively affect the kidneys, including chronic use or high doses of anti-inflammatory drugs for pain such as Advil or Motrin (ibuprofen) and Aleve (naproxen). Descovy for PrEP can be used with the hepatitis C drugs Harvoni or Zepatier. Monitor for tenofovir toxicities if used with Epclusa. Descovy should not be taken with certain anticonvulsants (including carbamazepine, oxcarbazepine, phenobarbital, and phenytoin), rifabutin, rifampin, rifapentine, or St. John’s wort. Concentrations of tenofovir, FTC, and other substances that clear the body through the kidneys could be increased (along with risk of toxicity) by the aminoglycoside antibiotics and the antivirals acyclovir, cidofovir, ganciclovir, valacyclovir, and valganciclovir. Tell your provider or pharmacist about all medications, herbals, and supplements you are taking or thinking of taking, prescribed or not.

Descovy for PrEP was not approved for the prevention of HIV via receptive vaginal sex. This is because the effectiveness of Descovy for PrEP was not evaluated in this population. A large study using Descovy for PrEP in cisgender women and adolescent girls, called PURPOSE-1, is underway. The tenofovir alafenamide (TAF) in Descovy and the tenofovir disoproxil fumarate (TDF) in Truvada (the first PrEP medication on the market) absorb, distribute, and concentrate differently in the body, but both are highly effective against the virus whether for treatment or prevention. TAF has less of a negative effect on renal function and bone mineral density than TDF, but the long-term clinical significance of the changes observed with the two medications remains unknown. Medical providers, however, prefer TAF over TDF for certain people who may be at higher risk for renal and bone toxicity (including youths and older individuals). Insurers must now cover PrEP and its associated services (such as STI testing) without cost (such as co-pays) to people, but the details of coverage can vary. This is as a result of the Grade A recommendation from the U.S. Preventative Services Task Force (USPSTF). A guide to help providers bill for PrEP services is available at nastad.org/resource/billing-coding-guide-hiv-prevention. Two excellent websites for finding a PrEP provider are preplocator.org and aidsvu.org—although any provider can prescribe PrEP. For more information, go to cdc.gov/hiv/basics/prep.html. Gilead Sciences helps people work with their insurance, including pre-authorizations, as well as provides free PrEP to uninsured people who are eligible and co-pay assistance for insured individuals up to $7,200 a year; contact the patient assistance hotline 24/7 at (877) 505-6986, or go to gileadadvancingaccess.com. DHHS HIV guidelines have a section on using PrEP for periconception, antepartum, and postpartum periods. PrEP Facts: Rethinking HIV Prevention and Sex is a closed Facebook group for people interested in or currently on PrEP, and their allies. Pregnant individuals can voluntarily enroll in the Antiretroviral Pregnancy Registry through their provider; go to apregistry.com.

Dr. Melanie Thompson:

Descovy was studied in cisgender gay and bisexual men and transgender women in the DISCOVER trial and found to be noninferior to Truvada as PrEP. Descovy was associated with lower rates of biomarkers of kidney toxicity, less bone density loss, and more weight gain, and higher LDL and HDL cholesterol than Truvada. Descovy is most valuable among people who are older or who already have or are at high risk for kidney toxicities or osteopenia/osteoporosis.

As with Truvada, people with hepatitis B may experience flairs if Descovy is stopped without other drugs on board to treat hepatitis B. 

My editorial comment: This intensely controversial trial (full disclosure: I was an investigator) showed why robust community engagement in trial design and execution should not be bypassed by sponsors. The exclusion of cisgender women, transgender men, and people who inject drugs worsens disparities and leaves an unacceptable void in oral PrEP options for these populations, some of which may be filled by injectable cabotegravir. (Note that a trial of Descovy is indeed beginning for cisgender women.) Luckily, Truvada and its generic options remain the first choice for PrEP for many people, including cisgender women who are pregnant or contemplating pregnancy, and the price is decreasing over time owing to generic competition.

For individuals, there should be no out-of-pocket cost for the drug or PrEP services (office visits, lab monitoring including STI screening) due to an “A” rating from the United States Preventative Services Task Force.

Activist Michael Broder:

TAF may be safer than TDF for bones and kidneys. This is especially important for people under age 25, who are still actively developing bone, and for people who have mild to moderate kidney disease. On the other hand, TAF has a worse profile than TDF when it comes to cholesterol and weight gain. Providers will weigh the choice based on their experience, and on the needs of each patient.