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PrEP using Tenofovir plus Emtricitabine May Offer Benefits even if HIV Infection Occurs

Animal studies of pre-exposure prophylaxis (PrEP) using tenofovir (Viread), with or without emtricitabine (Emtriva), have produced promising results, and large clinical trials in humans are currently underway. Prevention strategies using antiretroviral drugs are unlikely to be 100% effective, due to variations in efficacy, adherence, and other factors. But there is growing evidence that PrEP may have benefits even for individuals who become infected.

How Safe is HIV Serosorting for Men who have Sex with Men?

HIV “serosorting” -- in which HIV positive people have unprotected sex only with other positive people, and negative people only with other negatives -- has been proposed as a strategy for reducing the risk of HIV transmission. The method is far from foolproof, however, requiring that individuals accurately know and honestly convey their current status.

AIDS 2008: Pregabalin vs Placebo for the Treatment of Painful HIV-associated Peripheral Neuropathy

Painful peripheral neuropathy remains a significant problem for many HIV/AIDS patients and there are few palliative or otherwise helpful therapies for this serious adverse event that may be associated with antiretroviral drug treatment, HIV infection itself, or both.

Pregabalin, an anti-epileptic drug, has previously demonstrated efficacy in several neuropathic pain syndromes. The FDA has approved Pfizer's pregabalin (Lyrica) for the treatment of fibromyalgia.

At the XVII International AIDS Conference last week in Mexico City, David Simpson of the Mount Sinai Medical Center in New York City presented results from the first trial to evaluate the efficacy, safety, and tolerability of pregabalin as a treatment for pain associated with HIV sensory neuropathy.

This randomized, double-blind, placebo-controlled, multicenter trial included 302 participants, 151 allocated to receive pregabalin and 151 to receive placebo. At baseline, the mean pain score was about 6.93 for the pregabalin arm and 6.72 for the placebo arm.

There were 4 phases: 1-2 week screening, 2-week double-blind dose-adjustment (150-600 mg/day taken twice-daily), 12-week double-blind maintenance, and 1-week tapering off. Overall average daily dosage of pregabalin was 385.7 mg/day.

The primary efficacy measure was mean pain score using an 11-point numeric rating scale completed daily by patients; weekly man pain score was a supplemental analysis.

Results

• At weeks 1 and 2, patients taking pregabalin had significantly greater improvements in mean pain score relative to placebo:

• Week 2: -1.92 vs 1.43; P = 0.0393.

• In an analysis of PGIC scores, more patients taking pregabalin said their condition had improved, and fewer said it had worsened (P = 0.0077):

• 13.3% and 25.4%, respectively, experienced "no change."

• The most common adverse events (AEs) in the pregabalin arm were somnolence (23.2% pregabalin vs 8.6% placebo) and dizziness (19.2% vs 10.6%, respectively).

• Seven patients (4.6%) in the pregabalin group and 2 patients (1.3%) in the placebo group discontinued because of treatment-related AEs.

Based on these findings, the study authors concluded, "Pregabalin and placebo were associated with substantial improvements in pain and PGIC, with no significant difference in endpoint mean pain score. Adverse events were consistent with the tolerability profile of pregabalin in other neuropathic pain clinical trials."

Mount Sinai Medical Center, New York, NY; Pfizer Global Pharmaceuticals, New York, NY.

8/15/08

Reference

DM Simpson, TK Murphy, E Durso-De Cruz, and others. A randomized, double-blind, placebo-controlled, multicenter trial of pregabalin vs placebo in the treatment of neuropathic pain associated with HIV neuropathy. XVII International AIDS Conference (AIDS 2008). August 3-8, 2008. Mexico City. Abstract THAB0301.

Antiretroviral Therapy during Pregnancy Significantly Reduces Mother-to-child HIV Transmission, but is Linked to Low Birth Weight

Since the mid-1990s, it has been known that prophylactic use of certain antiretroviral drugs during pregnancy -- namely zidovudine (AZT; Retrovir) and nevirapine (Viramune) -- dramatically reduces the risk of mother-to-child HIV transmission. However, outcomes in women who use triple combination antiretroviral therapy during pregnancy are less well characterized.

In a report published in the September 12, 2008 issue of AIDS, researchers with the French/African Ditrame Plus and MTCT-Plus Projects studied pregnancy outcomes in 326 HIV-1-infected pregnant women receiving antiretroviral therapy in Abidjan, Cote d'Ivoire.

Between March 2001 and July 2003, HAART was not yet available, and women who would have been eligible for combination therapy based on their own disease status instead received a short-course of zidovudine (with or without lamivudine) plus a single dose of nevirapine during labor to prevent mother-to-child transmission (PMTCT group; n = 175). Between August 2003 and August 2007, women eligible for HAART received combination therapy (HAART group; n = 151). All infants received zidovudine and nevirapine after birth, and women were advised to either feed formula or exclusively breast-feed (shown to be safer than mixed feeding of breast milk plus other foods). Median CD4 cell counts were similar in the 2 groups (177 vs 182 cells/mm3, respectively).

The researchers recorded the frequencies of low birth weight (<2500 g), very low birth weight (below 2000 g), stillbirth, and infant mortality within the first year. Risk factors associated with low birth weight were investigated using a logistic regression model.

Results

• At 12 months, 3 infants (2.3%) became infected with HIV in the HAART group compared with 25 infants (16.1%) in the PMTCT group (P < 0.001).

• The rate of very low birth weight was similar in the 2 groups.

• The rate of low birth weight was nearly twice as high in HAART group compared with the PMTCT group (22.3% vs 12.4%; P = 0.02).

• In a multivariable analysis, after adjusting for maternal CD4 count, WHO disease stage, age, and body mass index (BMI), the following factors were significantly associated with low birth weight:

• HAART initiated before pregnancy (adjusted odds ratio [AOR] 2.88);

• HAART started during pregnancy (AOR 2.12);

• Low maternal BMI at the time of delivery (AOR 2.43).

• The rate of stillbirth was similar in both groups, at about 3%.

• The overall infant mortality rate during the first year was about 7%.

• Low birth weight and HAART use were not associated with a greater risk of infant death, though being HIV infected led to greater mortality.

Based on these findings, the study authors concluded that "HAART in pregnant African women with advanced HIV disease substantially reduced mother-to-child transmission, but was associated with low birth weight."

HIV transmission is less likely to occur when viral load is fully suppressed, and mothers are more likely to achieve undetectable viral load with combination HAART than with only zidovudine/nevirapine.

Given the highly significant reduction in the rate of HIV infection in babies born to women on HAART, and given that low birth weight infants were not more likely to die, this study indicates that the benefits of HAART for pregnant women outweigh the risks.

9/23/08

Reference

DK Ekouevi, PA Coffie, R Becquet, and others. Antiretroviral therapy in pregnant women with advanced HIV disease and pregnancy outcomes in Abidjan, Côte d'Ivoire. AIDS 22(14): 1815-1820. September 12, 2008 (Abstract).

AIDS 2008: Protective Effect of Circumcision against HIV Infection Is Sustained for Nearly 2 Years

Over the past two years, it has become increasingly clear that adult circumcision helps protect men from acquiring HIV. As previously reported recent studies have shown that circumcision reduced the rate of HIV infection by as much as 60% in high-prevalence countries in Africa. At the XVII International AIDS Conference last week in Mexico City, researchers who conducted one of the pivotal African studies in Kisumu, Kenya, reported follow-up data showing that the benefits appear to be long-lasting.

AIDS 2008: Didanosine (Videx EC) + Emtricitabine (Emtriva) + Atazanavir (Reyataz) Inferior for Initial HIV Treatment: PEARLS Trial

For a variety of reasons, physicians may recommend an alternative initial antiretroviral regimen rather than one of the first-line regimens recommended by current treatment guidelines. A once-daily regimen of didanosine (ddI; Videx-EC), emtricitabine (Emtriva), and unboosted atazanavir (Reyataz) has potential advantages over other alternative regimens, but the efficacy of this combination is unknown.

Agencies Release New Report on State of HIV Prevention Across the U.S.

The Kaiser Family Foundation and the National Alliance of State and Territorial AIDS Directors (NASTAD) has released a new report assessing the status of HIV prevention efforts in the U.S., at a time of increasing budget constraints.