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  3rd International Workshop on HIV & Women
January 14-15, 2013
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London Women Lag MSM and Heterosexual Men in Antiretroviral Response and Durability
  4th International Workshop on HIV & Women, January 13-14, 2014, Washington DC
Mark Mascolini
Gender disparities persist in response to first-line antiretroviral therapy, according to a 1131-person analysis at London's Royal Free Hospital [1]. Higher proportions of women than men who have sex with men (MSM) or non-MSM men failed to reach an undetectable viral load, switched at least one antiretroviral in their regimen, or stopped treatment completely.
The Royal Free Hospital HIV clinic cares for a diverse population of women and men in central London. This analysis involved all antiretroviral-naive people who began combination antiretroviral therapy from 2006 onwards and had at least one viral load measured while on treatment.
The analysis included 563 MSM with a median age of 39 when they started ART, 241 non-MSM men with a median age of 41, and 327 women (29% of the entire group) with a median age of 37. Most women, 60%, were black African, compared with 44% of non-MSM men and 1% of MSM. Almost all women, 97%, were infected during sex with men, and 86% of non-MSM men were infected during sex with women. Higher proportions of women (22%) and non-MSM men (30%) than MSM (12%) had an AIDS diagnosis before starting antiretrovirals. Median CD4 count when ART began was 219 in women, 218 and non-MSM men, and 298 in MSM.
Median year of starting ART was 2008 in all three groups. Total follow-up was similar in the three groups--2.9 years in women, 2.8 years in non-MSM men, and 3.0 years in MSM. A higher proportion of women (35%) took lopinavir/ritonavir than did men (20% in both male groups). But a lower proportion of women took another ritonavir-boosted protease inhibitor (22% versus 32% in both males groups) or efavirenz (38% versus 45% in non-MSM men and 42% in MSM). Thirty-two women (10%) were pregnant when they started antiretroviral therapy.
Similar proportions of women (84.7%), non-MSM men (84.3%), and MSM (88.8%) reached a viral load below 50 copies in the first year of treatment. But when the Royal Free team measured virologic response another way--as two viral loads above 200 copies more than 6 months after starting therapy--25% of women met that failure criterion, compared with 15% of non-MSM men and 10% of MSM. After 18 months of treatment, 9.8% of women had experienced virologic failure, compared with 6.2% of non-MSM men and 2.6% of MSM (P < 0.0001).
After statistical adjustment for factors than can affect virologic failure, women had well over a quadrupled risk of failure compared with MSM (adjusted hazard ratio [aHR] 4.63, 95% confidence interval [CI] 2.26 to 9.48), and non-MSM had well over a tripled risk of failure compared with MSM (aHR 3.69, 95% CI 1.76 to 7.74).
A higher proportion of women (42.6%) changed a component of their antiretroviral combination within 1 year of starting than did non-MSM men (35.5%) or MSM (26.9%) (P < 0.0001). And substantially more women (16.6%) than non-MSM men (12.1%) or MSM (9.6%) changed their regimen because of toxicity.
Within the first year of treatment, 15.4% of women, 12.0% of non-MSM men, and 5.0% of MSM had completely stopped their antiretroviral regimen for at least 2 weeks (P < 0.0001). After statistical adjustment for potential confounders, women had more than a tripled risk of completely stopping treatment than MSM (aHR 3.45, 95% CI 2.20 to 5.40, P < 0.0001) and non-MSM men had more than a doubled risk (aHR 2.28, 95% CI 1.35 to 3.83).
The Royal Free team concluded that women still run a higher risk of virologic failure than MSM or heterosexual men at their institution. Compared with men, women are more likely to swap out individual antiretrovirals or to stop therapy completely.
A previous UK CHIC cohort comparison of 2179 women and 1487 heterosexual men starting their first antiretroviral combination between 1998 and 2007 found similar rates of virologic suppression and rebound between women and men [2]. But men were almost 30% less likely to stop or switch their antiretroviral regimen (aHR 0.72, 95% CI 0.63 to 0.83). The Royal Free study shows that women have made little progress in trimming discontinuation and switch rates compared with heterosexual men since then.
1. Saunders P, Goodman A, Smith C, Marshall N, O'Connor J, Lampe F, Johnson MA. Gender disparities in treatment based outcomes persist in the era of modern ART. 4th International Workshop on HIV & Women, January 13-14, 2014, Washington DC. Abstract 20.
2. Barber TJ, Geretti AM, Anderson J, et al. Outcomes in the first year after initiation of first-line HAART among heterosexual men and women in the UK CHIC Study. Antivir Ther. 2011;16:805-814.