Back HIV Prevention Treatment as Prevention IAPAC Summit: At Least 25,000 People in the U.S. May Now Be Using PrEP

IAPAC Summit: At Least 25,000 People in the U.S. May Now Be Using PrEP


As many as 30,000 people in the U.S. may now be taking pre-exposure prophylaxis (PrEP) to prevent HIV, researchers reported at the 4th IAPAC Controlling the HIV Epidemic with Antiretrovirals summit in Paris last week. Meanwhile, as the summit also heard, European and other countries face frustrating delays in securing access to PrEP.

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Bob Grant from the UCSF Gladstone Institutes, principal investigator for the iPrEx study, told meeting attendees that a survey of U.S. pharmacies that dispense PrEP found that 8512 individuals had Truvada (tenofovir/emtricitabine) prescribed to them as PrEP since the beginning of 2012. At the last report on this study a year ago, the figure was 3253, so prescriptions have more than doubled in a year.

The true number of people on PrEP, however, is considerably higher, as not everyone on PrEP receives it through pharmacies included in the survey. The proportion of U.S. pharmacies participating in the PrEP survey has also declined during the year, from 55% to 39%, so the increase has probably been even greater and could be nearly 22,000, if non-reporting pharmacies prescribed PrEP at the same rate as reporting ones.

In addition to pharmacy-prescribed PrEP, an estimated 8000 people are receiving PrEP in demonstration studies, through the Medicaid system, or via the patient assistance program operated by Truvada manufacturer Gilead Sciences. This adds up to nearly 30,000 people.

But the true figure is likely to be somewhat lower, as non-reporting pharmacies may be prescribing less PrEP, and also because some people who received it may have already stopped using PrEP.

Ken Mayer, principal investigator of the ADAPT study, said that at his own clinic, the Fenway Health Center in Boston, 15% of those who started PrEP had already stopped; another 30% stopped PrEP but subsequently restarted.

However, the total number of PrEP users in the U.S. is now unlikely to be below 25,000.

The Fenway's PrEP project started in 2012, but 80% of its 663 participants started last year, reflecting a general recent expansion in PrEP use. This experience is echoed by that of other clinics. For instance, at New York City’s large Callen/Lorde Community Health Center, although PrEP has been on offer since March 2012, only 30 people had come forward for it up to January 2014. At that point demand started to increase and is still rising: the cumulative number of PrEP prescriptions there is now 982. At Kaiser Permanente in San Francisco, which had more than 650 people on PrEP at the latest report, interest in PrEP began rising in the fall of 2013, with a steeper increase after the CDC recommended it for people at risk in May 2014 (Kaiser was not included in the pharmacists survey).

Mayer said that this figure only represented one-twentieth of the people in the U.S. who might benefit from PrEP. It is estimated that there are approximately 275,000 gay men and 140,000 heterosexuals in the U.S. -- 415,000 people in total -- who are at the kind of risk of HIV infection that would justify taking PrEP.

Grant added that it still seemed to be the case that those who were at the highest risk were the most likely to ask for PrEP: 3 separate surveys in San Francisco have found that 4% to 10% of gay men with 1 sexual partner in the last year were now or had ever taken PrEP, compared to 11%-17% of those with 2 partners, and 25%-33% of those with 3 or more. "PrEP is essentially a demand-driven measure," he added.

Mayer said that PrEP prescribing was still skewed toward those who could afford it, with over 80% having it paid through private insurance and 80% of recipients being white gay men. The biggest barriers to PrEP use were still lack of demand and lack of insurance coverage; however, a survey of healthcare practitioners found that the third most common reason was that practitioners felt untrained to prescribe PrEP.

The Global Cost of PrEP

A number of speakers at the IAPAC meeting looked at PrEP prescribing outside the U.S.

Meg Doherty of the World Health Organization (WHO) went through the meta-analysis of PrEP studies that the WHO conducted to reach its most recent recommendations on PrEP. She said that the WHO considered PrEP urgently necessary for key affected populations such as men who have sex with men, who were at 19 times the risk of HIV than the general population globally, and transgender women, who were at 49 times the risk. As for cisgender (non-transgender) women, 20% of female sex workers in Nigeria, 50% in Zimbabwe, and 17% of young women in the general population in South Africa had HIV.

Despite the fact that some PrEP studies such as Fem-PrEP and VOICE had not found that PrEP was effective, the meta-analysis found that over all the studies, PrEP was 51% effective, preventing half of the infections that would otherwise have occurred, and that in people with over 70% adherence it was 70% effective. Its effectiveness was higher in men (62%) than in women (43%), and the same gap was observed if this was analyzed as anal versus vaginal sex. The analysis did confirm that PrEP seemed to be considerably less effective among young people, almost certainly owing to low adherence: it only prevented 29% of HIV infections that would otherwise have occurred in people under age 25.

There was no difference between the effectiveness of Truvada (51%) and solo tenofovir (49%) -- a fact that may guide future prescribing policy. The meta-analysis found that, with only the Ipergay study so far releasing results, there were not enough data on intermittent or "on demand" PrEP regimens to decide on their relative effectiveness.

As the WHO guidelines state, PrEP is probably economically affordable for people whose risk of HIV infection exceeds 3% a year, but that heterogeneity of risk in populations may make it hard to identify these people.

David Burns of the U.S. CDC said that a couple of sexual risk algorithms had been developed in the U.S. that accurately predicted someone’s risk of HIV infection over the last year. The San Diego Early Test (SDET) and EXPLORE algorithms both gave ''points" for condomless receptive anal sex with HIV-positive partners and with multiple partners (3 points each in the SDET score), and for any kind of sex with more than 10 partners or diagnosis of a bacterial sexually transmitted infection (2 points). EXPLORE also added in "chemsex" drug use.

In a validation of the SDET score, two-thirds of people diagnosed with early or acute HIV infection (compared with a matched control group who were not infected) had an SDET score of 5 or more for the previous year, while virtually none with an SDET score of 8 or more were not infected. (At the same time, 25% with early infection had an SDET score of zero, showing that not all risk is captured.)

Burns added that for PrEP to be more available, prices would have to fall: the inequity between the $78 a year that generic Truvada costs, and the $10,200 it costs at full price in the U.S., had to be ended.

Katie Callahan of the Clinton HIV/AIDS Initiative also said that making sure that only people at high risk for HIV receive PrEP was key to its economical use. In Kenya, the use of HIV drugs as treatment costs $8375 for every HIV infection averted due to their treatment-as-prevention effect. In a cohort of female sex workers with 3% annual HIV incidence, PrEP would cost $5593 per infection averted, and thus be a net cost-saving measure compared with treating those otherwise infected. If given to the general population with an incidence of 0.1% a year, however, PrEP would cost $128,205 per infection averted.

However, she pointed out, PrEP was not alone in needing to be targeted, it had just been subject to more rigorous cost analyses. In the case of home-based HIV testing, for instance, which has been widely promoted and found to be popular and effective in several African countries, background HIV incidence makes a huge difference to the affordability of such program. In a population with an HIV prevalence of 8%, the cost per test of a home-based test program is $6, the cost per HIV-positive person identified is $50, and the cost of linking each diagnosed person to care $57. But if HIV prevalence is 1%, then those figures become $15, $955, and $1698 respectively.

Callahan said that although both antiretroviral-related and non-antiretroviral-related costs in HIV program continued to fall, the UNAIDS target of 73% of all people with HIV on treatment and virally suppressed by 2020 would actually be more achievable if programs targeted those at most risk of HIV, rather than if they attempted universal testing and treatment.

Slow Progress in Europe

It was notable that Europe-based speakers at the IAPAC summit expressed frustration with the rate of progress towards achieving access to PrEP there. Jean-Michel Molina, principal investigator of the Ipergay study, said that the French Ministry of Health had now asked an expert panel and the French National AIDS Council to give recommendations for PrEP provision "but not too soon."

He said this posed a possibly dangerous situation, with more and more people asking for PrEP and, as a survey by AIDES recently documented, rising rates of informal usage of PrEP and requests for post-exposure prophylaxis (PEP) as a way of getting PrEP.

Sheena McCormack, principal investigator of the PROUD Study, said that she thought that the fears of European PrEP providers of an unaffordably high demand for PrEP were misplaced: "I think that we will struggle to get all those who need PrEP to recognize or accept they are at sufficient risk to need it," she commented.

She added that intermittent PrEP use on the Ipergay model could solve some of the problems of targeting: "In both Ipergay and PROUD we had some participants at low risk," she said. "In PROUD, 25% only had 1 condomless anal intercourse partner in the last 3 months. In an intermittent PrEP regimen, the lower the risk, the lower the use of drug."

Dominique Costagliola of ANRS, the French HIV research agency, said that despite the fact that 94% of those diagnosed in France are receiving antiretroviral therapy (ART), and that 60% of patients with CD4 counts over 500 cells/mm3 received ART from 2013 onwards compared with just 15% during 2010-2012, HIV prevalence in men who have sex with men was now 17% and annual incidence was 1.04% -- 6 times higher than the rate in people who inject drugs and 13 times the rate in women who were not French nationals, the next 2 highest-risk groups.

"There is a critical situation of men who have sex with men in Europe,” she said, "which is unlikely to be controlled by more HIV testing and the offer of ART at diagnosis."



International Association of Providers of AIDS Care. Controlling the HIV Epidemic with Antiretrovirals. October 1-2, 2015. All slide presentations are available online at