Search

Objective Integrase inhibitors, including dolutegravir (DTG), are associated with weight gain and obesity, especially when combined with tenofovir alafenamide (TAF). Obesity increases the risk of adverse pregnancy outcomes (APOs). This study aimed to predict the risk of APOs caused by treatment-associated obesity, using a hypothetical sample based on the ADVANCE trial. Design Risk prediction. Methods Firstly, a meta-analysis was performed to determine the relative risk (RR) for APOs in women with obese (≥30) versus normal prepregnancy BMIs (18.5-24.9). For the hypothetical sample, 3000 nonpregnant women with normal BMIs at Week 0 of treatment were evenly allocated across the following treatment arms: TAF/FTC+DTG, TDF/FTC+DTG, TDF/FTC/EFV. The treatment-associated obesity rates from ADVANCE were used to calculate the number of women with obese and normal BMIs expected at Week 96 in our sample. This was combined with the APO RRs to predict the number of women at risk of APOs, in each treatment arm, assuming they conceived at Week 96. Results At Week 96, the percentage of women predicted to be obese was 14.1% with TAF/FTC+DTG, 7.9% with TDF/FTC+DTG and 1.5% with TDF/FTC/EFV. The RR in women with obese versus normal BMIs was significantly higher for most APOs. Therefore, the number of women at risk of APOs was higher with TAF/FTC+DTG than TDF/FTC+DTG and TDF/FTC/EFV. For example, 11/1000 additional gestational hypertension cases were predicted with TAF/FTC+DTG, 6/1000 with TDF/FTC+DTG and 1/1000 with TDF/FTC/EFV. Conclusion Treatment-associated obesity increased the APO risk in women. This risk is likely to increase, as preliminary data from ADVANCE demonstrates ongoing weight gain beyond Week 96.

There are currently approximately 16 million people taking NNRTI-based first-line treatment in low-income and middle-income countries. Most of these patients are using the combination of tenofovir (TDF), lamivudine (3TC) and efavirenz (EFV). The integrase inhibitor dolutegravir (DTG) has shown an improved safety profile compared with EFV in randomized studies. DTG also has a high barrier to development of drug resistance. New co-formulated tablets with TDF/3TC/DTG are being introduced into LMICs, for a median price of $75 per person-year. The prodrug of TDF, tenofovir alafenamide (TAF) is cheaper to manufacture than TDF. A combined pill with TAF/3TC/DTG is also being launched in LMICs, at a similar low price. However, the clinical development programmes for DTG and TAF did not include extensive analysis of several key populations: pregnant women, people with HIV-tuberculosis (TB) coinfection taking rifampicin-based treatment, and treatment-naive or pretreated patients with NRTI drug resistance. An observational study in Botswana has shown an increased risk of neural tube defects when dolutegravir is used in early pregnancy. In LMICs, only 50% of patients have access to regular viral load testing, and genotypic resistance testing is rarely performed. There is currently no clinical data to support switching patients from TDF/3TC/EFV directly to TDF/3TC/DTG if their viral load is either detectable or unknown. New clinical trials and observational studies will be needed to better understand the consequences of this switch of treatment in LMICs. Clinical trials of new antiretrovirals in key populations should be conducted earlier in their development. This will ensure that new treatments can be introduced into LMICs soon after their launch in high-income countries.

Clinical trial data have shown that oral pre-exposure prophylaxis (PrEP) is efficacious when taken as prescribed; however, PrEP adherence is complex and must be understood within the context of variable risk for HIV infection and use of other HIV prevention methods. Different levels of adherence may be needed in different populations to achieve HIV prevention, and the optimal methods for achieving the necessary adherence for both individual and public health benefits are unknown. Guidance for PrEP use must consider these questions to determine the success of PrEP-based HIV prevention programs. In this article, we propose a new paradigm for understanding and measuring PrEP adherence, termed prevention-effective adherence, which incorporates dynamic HIV acquisition risk behaviors and the use of HIV alternative prevention strategies. We discuss the need for daily PrEP use only during periods of risk for HIV exposure, describe key issues for measuring and understanding relevant behaviors, review lessons from another health prevention field (i.e., family planning), and provide guidance for prevention-effective PrEP use. Moreover, we challenge emerging calls for sustained, near perfect PrEP adherence regardless of risk exposure and offer a more practical and public health-focused vision for this prevention intervention.

Nevirapine used in single doses to prevent mother-to-child transmission has been shown to be associated with the development of transient resistant mutations. Here we describe the presence of V106M in seven out of 141 South African women (5%) 6 weeks after receiving nevirapine. V106M is a novel resistance mutation found in subtype C viruses exposed to efavirenz. This mutation is thus also induced at a low frequency in subtype C viruses exposed to single dose nevirapine.