Two thirds of oral prep-using MSM would switch to long-term shots

One third of men who have sex with men (MSM) using daily oral PrEP for a year or more would “definitely switch” to a long-acting PrEP shot every 3 months, while another third would “probably switch,” according to results of a 90-man survey [1]. Hispanic and nonwhite men were significantly more likely to be among definite switchers.

Efficacy of daily oral PrEP with tenofovir/emtricitabine (TDF/FTC) depends on good adherence. Researchers are developing long-acting PrEP formulations that can be injected every 3 months in hopes that long-acting PrEP will promote adherence. Researchers at New York’s Aaron Diamond AIDS Research Center and Hunter College surveyed 90 gay or bisexual MSM taking daily TDF/FTC PrEP for 12 months or more to assess their interest in long-acting PrEP and motivators for switching or not switching.

Researchers told participants that long-acting injections remain in the blood a long time. After taking pills of the PrEP drug for a month to ensure safety, the men were told, they would come to the clinic every 3 months for two shots of the PrEP drug in the buttocks. Researchers asked how likely respondents would be to switch to injected PrEP and reasons why they would or would not switch.

The 90 participants averaged 35 years in age (range 23 to 63), 69% were white, 12% black, and 9% multiracial; 26% of these men were Hispanic. Two thirds of respondents had a college degree or more education, 42% had an annual income below $30,000, 46% earned between $30,000 and $74,999, and 12% earned more.

Thirty-three men (37%) said they would definitely switch from daily oral PrEP to long-acting injected PrEP, while another 28 (31%) said they would probably switch. Twenty men (22%) weren’t sure about switching, 7 (8%) said they probably would not switch, and only 1 man (1%) stated he would definitely not switch. Definite switchers were significantly more likely to be nonwhite (P = 0.001) and to be Hispanic (P = 0.017). Men in the middle-income range ($30,000 to $74,999) were least likely to say they would switch to PrEP injections (P = 0.063).

More than half of the 33 definite switchers (51.5%) named convenience as a motivating factor, while 30% listed not having to take a daily pill as a motivator. Psychosocial factors for opting to switch included eliminating anxiety about missing doses and have “less to think/worry about” with a quarterly shot than a daily pill.

Among 56 men who were not definite switchers, 18 (32%) listed safety of shots as a concern, while 4 (7%) listed efficacy. One man cited possibly waning efficacy during the tail of the injection period. Other concerns about PrEP shots included pain (6%) and anxiety about shots (2%). A few men who were not definite switchers (9%) said taking a daily pill gave them a sense of control and they would not trust a shot to protect them. Some men (9%) leaned away from switching because they felt satisfied with daily pill PrEP.

The researchers concluded that product- and patient-level variables–including psychosocial factors–inform opinions about switching to long-acting injected PrEP. They recommended research on “development of tools to support decision-making around PrEP modalities” that consider psychosocial concerns found in this study.

Reference

1. Meyers K, Golub SA. To switch or not to switch: anticipating choices in biomedical HIV prevention. HIV Research for Prevention (HIVR4P 2016), October 17-19, 2016, Chicago. Abstract P24.15.