Projecting the clinical benefits and risks of using efavirenz-containing antiretroviral therapy regimens in women of childbearing age

Inclusion of pregnant women in antiretroviral drug research: what is needed to move forwards?

INTRODUCTION

To adequately ascertain drug safety and efficacy, drug trials need to include participants from all groups likely to receive the medication following approval. Pregnant women, however, are mostly excluded from trials, and women participating are often required to use highly effective contraception and taken off study product (even off study) if they conceive. There is little commercial incentive for including pregnant women in clinical trials, even when preclinical animal and human pharmacokinetic and safety data appear reassuring. With this conservative approach, large numbers of pregnant women are exposed to drug postlicensing with little known about drug safety and efficacy, and little done to systematically monitor outcomes of pregnancy exposure.

DISCUSSION

The article focuses on antiretrovirals for treating and preventing HIV, and presents potential approaches which could extend to other therapeutic areas, to obtaining adequate and timely data to inform use of these drugs in this population. Most importantly the pregnancy risk profile of investigational agents can be systematically stratified from low to high risk, based on guidelines from regulatory bodies. This stratification can determine the progress through preclinical work with animals and non-pregnant women to opportunistic studies among women who become pregnant on a clinical trial or within routine clinical treatment. Stratification can include pregnant women in clinical trials, concurrent with Phase II/III trials in non-pregnant adults, and ultimately to postmarketing surveillance for outcomes in pregnant women and their infants. Each step can be enabled by clear criteria from international and local regulatory bodies on progression through study phases, standardized protocols for collecting relevant data, collaborative data sharing, pregnancy outcomes surveillance systems supported by committed funding for these endeavours.

CONCLUSIONS

A formalized step-wise approach to including pregnant women in antiretroviral drug research should become the new norm. Systematic implementation of this approach would yield more timely and higher quality pregnancy dosing, safety and efficacy data. Through more vigorous action, regulatory bodies could responsibly overcome reluctance to include pregnant women in drug trials. Funders, researchers and programme implementers need to be galvanized to progressively include pregnant women in research - the use of newer, more effective drugs in women is at stake (349).

Comparative Safety of Antiretroviral Treatment Regimens in Pregnancy

IMPORTANCE

Maternal antiretroviral treatment (ART) started before conception may increase the risk for adverse birth outcomes among women with human immunodeficiency virus (HIV) infection, but whether the risk differs by ART regimen is unknown.

OBJECTIVE

To compare the risk for selected birth outcomes by maternal ART regimen.

DESIGN, SETTING, AND PARTICIPANTS

This observational birth outcomes surveillance study compared all live births and stillbirths with a gestational age of at least 24 weeks in 8 geographically dispersed government hospitals throughout Botswana (approximately 45% of births nationwide). Data were collected from August 15, 2014, through August 15, 2016.

EXPOSURES

Births among HIV-infected women who started 3-drug ART regimens before their last menstrual period and did not switch or stop ART in pregnancy were considered to be ART exposed from conception.

MAIN OUTCOMES AND MEASURES

The primary outcomes were any adverse birth outcome, including stillbirth, preterm birth (<37 weeks), small size for gestational age (SGA; <10th percentile of weight for gestational age) or neonatal death (<28 days from delivery), and any severe adverse outcome, including very preterm birth (<32 weeks), very SGA (<3rd percentile of weight for gestational age), stillbirth, and neonatal death.

RESULTS

Information was available for 47 027 of 47 124 births (99.8%) at surveillance maternity hospitals (mean [SD] age of mothers, 26.86 [6.45] years). Among 11 932 HIV-exposed infants, 5780 (48.4%) were ART exposed from conception. Adverse birth outcomes were more common among HIV-exposed infants than HIV-unexposed infants (39.6% vs 28.9%; adjusted relative risk [ARR], 1.40; 95% CI, 1.36-1.44). The risk for any adverse birth outcome was lower among infants exposed from conception to tenofovir disoproxil fumarate, emtricitabine, and efavirenz (TDF-FTC-EFV) (901 of 2472 [36.4%]) compared with TDF-FTC and nevirapine (NVP) (317 of 760 [41.7%]; ARR, 1.15; 95% CI, 1.04-1.27); TDF-FTC and lopinavir-ritonavir (TDF-FTC-LPV-R) (112 of 231 [48.5%]; ARR, 1.31; 95% CI, 1.13-1.52); zidovudine, lamivudine, and NPV (ZDV-3TC-NVP) (647 of 1365 [47.4%]; ARR, 1.30; 95% CI, 1.20-1.41); or ZDV-3TC-LPV-R (75 of 167 [44.9%]; ARR, 1.21; 95% CI, 1.01-1.45). The risk for any severe adverse outcome was also lower among infants exposed from conception to TDF-FTC-EFV (303 of 2472 [12.3%]) compared with TDF-FTC-NVP (136 of 760 [17.9%]; ARR, 1.44; 95% CI, 1.19-1.74), TDF-FTC-LPV-R (45 of 231 [19.5%]; ARR, 1.58; 95% CI, 1.19-2.11), ZDV-3TC-NVP (283 of 1365 [20.7%]; ARR, 1.68; 95% CI, 1.44-1.96), or ZDV-3TC-LPV-R (39 of 167 [23.4%]; ARR, 1.93; 95% CI, 1.43-2.60) from conception. Compared with TDF-FTC-EFV, all other regimens were associated with higher risk for SGA; ZDV-3TC-NVP was associated with higher risk of stillbirth, very preterm birth, and neonatal death; and ZDV-3TC-LPV-R was associated with higher risk for preterm birth, very preterm birth, and neonatal death.

CONCLUSIONS AND RELEVANCE

Among infants exposed to ART from conception, TDF-FTC-EFV was associated with a lower risk for adverse birth outcomes than other ART regimens.

Antiretroviral treatment in HIV-1 infected pediatric patients: focus on efavirenz

Efavirenz is a non-nucleoside reverse transcriptase inhibitor (NNRTI), used for the treatment of human immunodeficiency virus (HIV)-1 infection. Approved by the US Food and Drug Administration in 1998, its indication was recently extended to include children as young as 3 months of age. The World Health Organization and many national guidelines consider efavirenz to be the preferred NNRTI for first-line treatment of children over the age of 3 years. Clinical outcomes of patients on three-drug antiretroviral regimens which include efavirenz are as good as or better than those for patients on all other currently approved HIV medications. Efavirenz is dosed once daily and has pediatric-friendly formulations. It is usually well tolerated, with central nervous system side effects being of greatest concern. Efavirenz increases the risk of neural tube defects in nonhuman primates and therefore its use during the first trimester of pregnancy is limited in some settings. With minimal interactions with antituberculous drugs, efavirenz is preferred for use among patients with HIV/tuberculosis coinfection. Efavirenz can be rendered inactive by a single point mutation in the reverse transcriptase enzyme. Newer NNRTI drugs such as etravirine, not yet approved for use in children under the age of 6 years, may maintain their activity following development of efavirenz resistance. This review highlights key points from the existing literature regarding the use of efavirenz in children and suggests directions for future investigation.

Antiretroviral therapy, pregnancy, and birth defects: a discussion on the updated data

An increasing number of HIV-infected women of childbearing age are initiating antiretroviral therapy (ART) worldwide. This review aims to discuss updated data of the eligible ART regimens and their role in inducing birth defects in utero. Zidovudine and lamivudine plus a non-nucleoside reverse-transcriptase inhibitor or protease inhibitor (PI) is the first-line regimen applied. The role of zidovudine exposition monotherapy or associated with other ART in inducing birth defects remains inconclusive. The main organ systems involved are genitourinary and cardiovascular. For HIV-infected pregnant women, World Health Organization (WHO) guidelines up to 2010 recommend the same group of drugs that are prescribed to nonpregnant women. The exception is efavirenz, which has been associated with an increase in the risk of teratogenicity. Increased rates of birth defects were found in large cohorts and computational studies conducted recently in infants exposed to efavirenz-containing regimens. The combination of zidovudine and lamivudine and lopinavir/ritonavir is one of the most used ART regimens for prevention of mother-to-child-transmission. Conflicting data about the role of PI exposure in utero and birth defects have been reported. However, a reduced number of studies evaluating the role of PI in inducing birth defects in women are available. An association between prematurity and PI exposure in pregnancy was extensively described. Some questions arise due to the tendency of initiating ART early in the life of HIV-infected individuals or those at risk of infection. Longtime exposure to different ART regimens and the potential effect of birth-defect induction in pregnancy are not completely understood. Developing regions harbor the highest numbers of women of reproductive age exposed to ART. Most of the largest and expressive data come from developed countries, and could not be sufficiently representative of pregnant women living in developing countries.

Association between efavirenz-based compared with nevirapine-based antiretroviral regimens and virological failure in HIV-infected children

IMPORTANCE

Worldwide, the nonnucleoside reverse transcriptase inhibitors (NNRTIs) efavirenz and nevirapine are commonly used in first-line antiretroviral regimens in both adults and children with human immunodeficiency virus (HIV) infection. Data on the comparative effectiveness of these medications in children are limited.

OBJECTIVE

To investigate whether virological failure is more likely among children who initiated 1 or the other NNRTI-based HIV treatment.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort study of children (aged 3-16 years) who initiated efavirenz-based (n = 421) or nevirapine-based (n = 383) treatment between April 2002 and January 2011 at a large pediatric HIV care setting in Botswana.

MAIN OUTCOMES AND MEASURES

The primary outcome was time from initiation of therapy to virological failure. Virological failure was defined as lack of plasma HIV RNA suppression to less than 400 copies/mL by 6 months or confirmed HIV RNA of 400 copies/mL or greater after suppression. Cox proportional hazards regression analysis compared time to virological failure by regimen. Multivariable Cox regression controlled for age, sex, baseline immunologic category, baseline clinical category, baseline viral load, nutritional status, NRTIs used, receipt of single-dose nevirapine, and treatment for tuberculosis.

RESULTS

With a median follow-up time of 69 months (range, 6-112 months; interquartile range, 23-87 months), 57 children (13.5%; 95% CI, 10.4%-17.2%) initiating treatment with efavirenz and 101 children (26.4%; 95% CI, 22.0%-31.1%) initiating treatment with nevirapine had virological failure. There were 11 children (2.6%; 95% CI, 1.3%-4.6%) receiving efavirenz and 20 children (5.2%; 95% CI, 3.2%-7.9%) receiving nevirapine who never achieved virological suppression. The Cox proportional hazard ratio for the combined virological failure end point was 2.0 (95% CI, 1.4-2.7; log rank P < .001, favoring efavirenz). None of the measured covariates affected the estimated hazard ratio in the multivariable analyses.

CONCLUSIONS AND RELEVANCE

Among children aged 3 to 16 years infected with HIV and treated at a clinic in Botswana, the use of efavirenz compared with nevirapine as initial antiretroviral treatment was associated with less virological failure. These findings may warrant additional research evaluating the use of efavirenz and nevirapine for pediatric patients.

Protocol for a drugs exposure pregnancy registry for implementation in resource-limited settings

BACKGROUND

The absence of robust evidence of safety of medicines in pregnancy, particularly those for major diseases provided by public health programmes in developing countries, has resulted in cautious recommendations on their use. We describe a protocol for a Pregnancy Registry adapted to resource-limited settings aimed at providing evidence on the safety of medicines in pregnancy.

METHODS/DESIGN

Sentinel health facilities are chosen where women come for prenatal care and are likely to come for delivery. Staff capacity is improved to provide better care during the pregnancy, to identify visible birth defects at delivery and refer infants with major anomalies for surgical or clinical evaluation and treatment. Consenting women are enrolled at their first antenatal visit and careful medical, obstetric and drug-exposure histories taken; medical record linkage is encouraged. Enrolled women are followed up prospectively and their histories are updated at each subsequent visit. The enrolled woman is encouraged to deliver at the facility, where she and her baby can be assessed.

DISCUSSION

In addition to data pooling into a common WHO database, the WHO Pregnancy Registry has three important features: First is the inclusion of pregnant women coming for antenatal care, enabling comparison of birth outcomes of women who have been exposed to a medicine with those who have not. Second is its applicability to resource-poor settings regardless of drug or disease. Third is improvement of reproductive health care during pregnancies and at delivery. Facility delivery enables better health outcomes, timely evaluation and management of the newborn, and the collection of reliable clinical data. The Registry aims to improves maternal and neonatal care and also provide much needed information on the safety of medicines in pregnancy.

HIV treatment and care in resource-constrained environments: challenges for the next decade

Many successes have been achieved in HIV care in low- and middle-income countries (LMIC): increased number of HIV-infected individuals receiving antiretroviral treatment (ART), wide decentralization, reduction in morbidity and mortality and accessibility to cheapest drugs. However, these successes should not hide existing failures and difficulties. In this paper, we underline several key challenges. First, ensure long-term financing, increase available resources, in order to meet the increasing needs, and redistribute the overall budget in a concerted way amongst donors. Second, increase ART coverage and treat the many eligible patients who have not yet started ART. Competition amongst countries is expected to become a strong driving force in encouraging the least efficient to join better performing countries. Third, decrease early mortality on ART, by improving access to prevention, case-finding and treatment of tuberculosis and invasive bacterial diseases and by getting people to start ART much earlier. Fourth, move on from WHO 2006 to WHO 2010 guidelines. Raising the cut-off point for starting ART to 350 CD4/mm³ needs changing paradigm, adopting opt-out approach, facilitating pro-active testing, facilitating task shifting and increasing staff recruitments. Phasing out stavudine needs acting for a drastic reduction in the costs of other drugs. Scaling up routine viral load needs a mobilization for lower prices of reagents and equipments, as well as efforts in relation to point-of-care automation and to maintenance. The latter is a key step to boost the utilization of second-line regimens, which are currently dramatically under prescribed. Finally, other challenges are to reduce lost-to-follow-up rates; manage lifelong treatment and care for long-term morbidity, including drug toxicity, residual AIDS and HIV-non-AIDS morbidity and aging-related morbidity; and be able to face unforeseen events such as socio-political and military crisis. An old African proverb states that the growth of a deep-rooted tree cannot be stopped. Our tree is well rooted in existing field experience and is, therefore, expected to grow. In order for us to let it grow, long-term cost-effectiveness approach and life-saving evidence-based programming should replace short-term budgeting approach.

Efavirenz conceptions and regimen management in a prospective cohort of women on antiretroviral therapy

Use of the antiretroviral drug efavirenz (EFV) is not recommended by the WHO or South African HIV treatment guidelines during the first trimester of pregnancy due to potential fetal teratogenicity; there is little evidence of how clinicians manage EFV-related fertility concerns. Women on antiretroviral therapy (ART) were enrolled into a prospective cohort in four public clinics in Johannesburg, South Africa. Fertility intentions, ART regimens, and pregnancy testing were routinely assessed during visits. Women reporting that they were trying to conceive while on EFV were referred for regimen changes. Kaplan-Meier estimators were used to assess incidence across ART regimens. From the 822 women with followup visits between August 2009–March 2011, 170 pregnancies were detected during study followup, including 56 EFV conceptions. Pregnancy incidence rates were comparable across EFV, nevirapine, and lopinavir/ritonavir person-years (95% 100/users (P = 0.25)); incidence rates on EFV were 18.6 Confidence Interval: 14.2–24.2). Treatment substitution from EFV was made for 57 women, due to pregnancy intentions or actual pregnancy; however, regimen changes were not systematically applied across women. High rates of pregnancy on EFV and inconsistencies in treatment management suggest that clearer guidelines are needed regarding how to manage fertility-related issues in. women on EFV-based regimens.