Surveillance of ARV safety in pregnancy and breastfeeding: towards a new framework

Challenges, risks, and opportunities of antiretroviral drugs in women of reproductive potential

INTRODUCTION

The HIV/AIDS epidemic has been one of the greatest challenges in global health, significantly affecting women of reproductive potential. Considerable advances in antiretroviral therapy for women living with HIV have contributed to improvements in quality of life, better reproductive and birth outcomes, and a reduced risk of perinatal transmission.

AREAS COVERED

Despite the progress made, persistent challenges in access and adherence to antiretroviral drugs may limit their benefits for some women. More pharmacokinetic and safety studies in pregnant and lactating women are urgently needed, as are prospective surveillance systems to evaluate associations between fetal and infant antiretroviral exposures, drug-drug interactions, and pregnancy outcomes.

EXPERT OPINION

Multipurpose technologies, such as combined HIV and other STI or unintended pregnancy prevention, and innovative delivery methods, such as the development of long-acting antiretrovirals, have the potential to reduce adherence challenges and enhance quality of life for women with HIV. Parallel advances in drug safety testing and surveillance are needed to ensure the health and safety of women with or at risk for HIV and children at risk for perinatal transmission.

Setting the research agenda: involving parents in research on children who are HIV-free

INTRODUCTION

There is growing interest in health, developmental and survival outcomes of children who are born HIV-free to women living with HIV (children born HIV-free). To date, the research agenda has been largely determined by researchers, funders and policy makers, with limited involvement of parents, who are key stakeholders. Researchers at UCL Great Ormond Street Institute of Child Health in partnership with community-based organisation 4M Network of Mentor Mothers conducted two workshops with parents in March 2022 to establish research priorities for children born HIV-free, and key considerations for methodological approaches both to research and engagement with the affected communities.

DISCUSSION

When exploring research on children born HIV-free, we consider the following: what aspects of current research are aligned with women and parents' priorities, what is missing and what approaches would be preferred. A holistic approach to research on children born HIV-free should be prioritised, focussing on a breadth of outcomes and how they intersect. Secondary use of existing data sources should be maximised to facilitate this, with a view of monitoring the long-term effects of fetal antiretroviral drug exposure alongside other key health and developmental outcomes. Involving and engaging with parents, and children where possible, must be at the heart of research design to maximise relevance and impact of findings for the affected communities. Potential barriers to engaging with individuals who were children born HIV-free include parental disclosure and individuals not identifying as a child born HIV-free to a mother living with HIV. Stigma-free language must be incorporated into the vocabulary of researchers and other stakeholders, avoiding reference to exposure; we propose the term "children born HIV-free."

CONCLUSIONS

Mothers and parents living with HIV should be involved in research about their children born HIV-free and are key in identifying research priorities so that findings may translate into an impact on their children's health and wellbeing. Meaningful involvement of women living with HIV through trusted community partners is an effective mechanism by which to elicit views on research about their children.

Adverse perinatal outcomes associated with prenatal exposure to protease-inhibitor-based versus non-nucleoside reverse transcriptase inhibitor-based antiretroviral combinations in pregnant women with HIV infection: a systematic review and meta-analysis

BACKGROUND

About 1.3 million pregnant women lived with HIV and were eligible to receive antiretroviral therapy (ART) worldwide in 2021. The World Health Organization recommends protease inhibitors (PI)-based regimen as second or third-line during pregnancy. With remaining pregnant women exposed to PIs, there is still an interest to assess whether this treatment affects perinatal outcomes. Adverse perinatal outcomes after prenatal exposure to PI-based ART remain conflicting: some studies report an increased risk of preterm birth (PTB) and low-birth-weight (LBW), while others do not find these results. We assessed adverse perinatal outcomes associated with prenatal exposure to PI-based compared with non-nucleoside reverse transcriptase (NNRTI)-based ART.

METHODS

We performed a systematic review searching PubMed, Reprotox, Clinical Trial Registry (clinicaltrials.gov) and abstracts of HIV conferences between 01/01/2002 and 29/10/2021. We used Oxford and Newcastle-Ottawa scales to assess the methodological quality. Studied perinatal outcomes were spontaneous abortion, stillbirth, congenital abnormalities, PTB (< 37 weeks of gestation), very preterm birth (VPTB, < 32 weeks of gestation), LBW (< 2500 grs), very low-birth-weight (VLBW, < 1500 g), small for gestational age (SGA) and very small for gestational age (VSGA). The association between prenatal exposure to PI-based compared to NNRTI-based ART was measured for each adverse perinatal outcome using random-effect meta-analysis to estimate pooled relative risks (RR) and their corresponding 95% confidence intervals (CI). Pre-specified analyses were stratified according to country income and study quality assessment, and summarized when homogeneous.

RESULTS

Out of the 49,171 citations identified, our systematic review included 32 published studies, assessing 45,427 pregnant women. There was no significant association between prenatal exposure to PIs compared to NNRTIs for VPTB, LBW, SGA, stillbirth, and congenital abnormalities. However, it was inconclusive for PTB, and PI-based ART is significantly associated with an increased risk of VSGA (sRR 1.41 [1.08-1.84]; I² = 0%) compared to NNRTIs.

CONCLUSIONS

We did not report any significant association between prenatal exposure to PIs vs NNRTIs-based regimens for most of the adverse perinatal outcomes, except for VSGA significantly increased (+ 41%). The evaluation of antiretroviral exposure on pregnancy outcomes remains crucial to fully assess the benefice-risk balance, when prescribing ART in women of reproductive potential with HIV.

PROSPERO NUMBER

CRD42022306896.

Clinical and population-based study design considerations to accelerate the investigation of new antiretrovirals during pregnancy

Introduction

Pregnant women are routinely excluded from clinical trials, leading to the absence or delay in even the most basic pharmacokinetic (PK) information needed for dosing in pregnancy. When available, pregnancy PK studies use a small sample size, resulting in limited safety information. We discuss key study design elements that may enhance the timely availability of pregnancy data, including the role and timing of randomized controlled trials (RCTs) to evaluate pregnancy safety; efficacy and safety outcome measures; stand‐alone protocols, platform trials, single arm studies, sample size and the effect that follow‐up time during gestation has on analysis interpretations; and observational studies.

Discussion

Pregnancy PK should be studied during drug development, after dosing in non‐pregnant persons is established (unless non‐clinical or other data raise pregnancy concerns). RCTs should evaluate the safety during pregnancy of priority new HIV agents that are likely to be used by large numbers of females of childbearing age. Key endpoints for pregnancy safety studies include birth outcomes (prematurity, small for gestational age and stillbirth) and neonatal death, with traditional adverse events and infant growth also measured (congenital anomalies are best studied through surveillance). We recommend that viral efficacy be studied as a secondary endpoint of pregnancy RCTs, once PK studies confirm adequate drug exposure in pregnancy. RCTs typically use a stand‐alone protocol for new agents. In contrast, master protocols using a platform design can add agents over time, possibly speeding safety data ascertainment. To speed accrual, stand‐alone pregnancy trial protocols can include pre‐specified starting rules based upon adequate PK levels in pregnancy; and seamless master protocols or platform trials can include a pregnancy PK and safety component. When RCTs are unethical or cost‐prohibitive, observational studies should be conducted, preferably using target trial emulation to avoid bias.

Conclusions

Pregnancy PK needs to be obtained earlier in drug evaluation. Timely RCTs are needed to understand safety in pregnancy for high‐priority new HIV agents. RCTs that enrol pregnant women should focus on outcomes unique to pregnancy, and observational studies should focus on questions that RCTs are not equipped to answer.

Accelerating investigation of new HIV drugs in pregnancy: advancing the research agenda from theory to action

Introduction

Historical approaches to clinical development of novel therapeutics for treatment and prevention of HIV have led to unacceptable delays in the generation of data to support optimal antiretroviral drug use in pregnancy. Over the last 5 years, multiple stakeholders have voiced their concerns around the exclusion of pregnant women from drug trials, and some progress has been made to consolidate principles and forge consensus. Building on ongoing efforts, the World Health Organization (WHO) and the International Maternal Paediatric Adolescent AIDS Clinical Trials Network (IMPAACT) convened a technical consultation designed to move the discussion from theory to practice.

Discussion

Accelerating the inclusion of pregnant women in pre‐licensure clinical trials, with a goal to have pharmacokinetics (PK) and preliminary safety data for all new HIV agents in pregnancy available at the time of drug approval, requires: (1) performing non‐clinical developmental and reproductive toxicology studies early in drug development for all new HIV agents; (2) recognizing and acting on the central role of women of childbearing potential affected by HIV through the research being conducted and the dissemination of associated results; (3) enrolling pregnant women in studies to specifically determine pregnancy PK and preliminary safety, as soon as late non‐clinical studies are completed with no negative signals, for all new HIV agents that have demonstrated preliminary evidence of safety and efficacy from phase 2 trials; (4) investigating adverse pregnancy and birth outcomes through dedicated pregnancy safety studies for all new priority HIV agents; and (5) expanding active surveillance of drug safety in pregnancy for rare events, such as birth defects.

Strategic actions to pursue include developing tools and resources to support designing and implementing studies among pregnant and breastfeeding women, identifying and promoting modifications of the regulatory framework that are supportive of systematic ethical investigation of new drugs in pregnancy, coordinating surveillance efforts, mobilizing key stakeholders and promoting transparency and accountability for all involved.

Conclusions

With more than 19 million women living with HIV worldwide, ensuring greater inclusion of pregnant women in research on novel therapeutics is a priority to support drug optimization and effective introduction of innovations for treatment and prevention of HIV.