Increase in transaminase levels following the use of raltegravir in a woman with a high HIV viral load at 35 weeks of pregnancy

Relationship between raltegravir trough plasma concentration and virologic response and the impact of therapeutic drug monitoring during pregnancy

BACKGROUND

Limited data is available on raltegravir (RAL) pharmacokinetics during pregnancy and the value of therapeutic drug monitoring (TDM) in pregnancy is unknown. This study aims to describe RAL trough plasma concentrations (C_trough) during pregnancy and review the impact of RAL TDM on outcomes.

METHODS

Women from the prospective mother-infant HIV cohort of Mother and Children's Infectious Diseases Center who received RAL during their pregnancy between 2011-2020 were included. TDM reports were reviewed and C_trough values estimated when possible, using historical RAL half-lives.

RESULTS

We included 76 pregnant women of which 47 underwent TDM. We observed a significant association between virological response and C_trough (p-value .034) with an increase of 0.1 mg/L corresponding to a 2.96 reduction in the risk of having a detectable viral load. The results indicated that in pregnant women a RAL C_trough threshold of 0.04 mg/L has a higher specificity (75%) as compared to our current C_trough target value of 0.02 mg/L (25%) and an acceptable sensitivity (77%). No significant differences were observed between C_trough at each trimester. When comparing pregnancies with and without TDM, no statistically significant differences were observed in the virologic response during pregnancy and at delivery, or with the need for triple antiretroviral prophylaxis in newborns.

CONCLUSIONS

An association between RAL C_trough and viral load was observed and achieving a RAL C_trough of 0.04 mg/L or greater is a predictor of virologic response in pregnant women. The impact of TDM in pregnancy, however, could not be demonstrated.

Antiretroviral Options and Treatment Decisions During Pregnancy

The majority of pediatric human immunodeficiency virus (HIV) infections are the result of vertical transmissions that occur during pregnancy, childbirth, and breastfeeding. The treatment of all pregnant persons living with HIV remains a global health initiative. Early and consistent use of antiretroviral therapy throughout pregnancy and childbirth drastically reduces the risk of perinatal transmission of HIV, resulting in fewer children living with the disease worldwide. Given that the maternal HIV viral load is the strongest predictor of perinatal transmission, suppressive antiretroviral treatment during pregnancy is the principal means to eliminate transmission of HIV from mother to child. With the use of combined antiretroviral therapy, typically with dual-nucleoside reverse transcriptase inhibitors plus an integrase strand transfer inhibitor or a ritonavir-boosted protease inhibitor, HIV-infected mothers can now achieve virologic suppression to undetectable levels and yield a perinatal transmission rate of less than 2%. Important considerations of HIV treatment in pregnancy include the safety and efficacy of antiretroviral drugs, altered pregnancy-related pharmacokinetics, potential for birth defects or adverse neonatal outcomes, and individualized delivery planning based on maternal viral load. This practical review article summarizes the options, considerations, and recommendations for antiretroviral treatment in pregnancy to reduce perinatal HIV transmission and optimize health outcomes for mothers and infants worldwide.

The Use of Integrase Strand Transfer Inhibitors to Treat HIV in Pregnancy

For pregnant women with HIV, antiretroviral therapy (ART) plays a key role in prevention of perinatal transmission. Newer antiretroviral regimens now contain integrase strand transfer inhibitors, which have been found to rapidly suppress HIV viral load in nonpregnant women; however, there are limited data for use in pregnancy. Here, we present the case of a pregnant woman with well-controlled HIV on a well-tolerated prepregnancy regimen of bictegravir, emtricitabine, and tenofovir alafenamide. As there are limited safety data on bictegravir in pregnancy, this ART regimen was changed to a preferred regimen for pregnancy. In the second trimester, because of adverse effects from the new ART regimen and after a risk-benefit discussion, the patient restarted the original regimen. She was able to maintain viral suppression until giving birth.

A Single-Center Retrospective Cohort Analysis of Maternal and Infant Outcomes in HIV-Infected Mothers Treated with Integrase Inhibitors During Pregnancy

Introduction

Integrase strand transfer inhibitors (INSTI) are currently being investigated for the treatment of HIV in pregnancy. The purpose of this study is to evaluate the differences in maternal and infant outcomes in HIV-positive mothers treated with INSTI-containing antiretroviral therapy (ART) during pregnancy compared to protease inhibitor (PI)-containing ART.

Methods

A retrospective, cohort study of INSTI- and PI-based ART used in pregnancy between 2007 and 2015 was performed. The primary objective was to evaluate the differences in viral load (VL) suppression prior to delivery. Secondary endpoints included time to and duration of VL suppression and safety parameters in both mothers and infants. For the primary analysis, the two arms were matched 1:2 INSTI to PI based on the presence or absence of viremia at the time of pregnancy determination. Additional analysis was performed on the entire matched and unmatched dataset.

Results

Twenty-one patients were matched (7 INSTI and 14 PI). There were no significant differences between groups with respect to the proportion of patients with VL suppression prior to delivery (71.4% INSTI vs. 92.9% PI, p = 0.247), and there were no significant differences in any of the secondary endpoints. Patients with documented adherence issues were statistically more likely to not be virologically suppressed prior to delivery (p = 0.002).

Conclusion

No differences in efficacy or safety were found between patients treated with INSTIs compared to PIs. This study supports the further investigation of the use of INSTIs during pregnancy to reduce HIV transmission.

Antiretroviral Therapy Containing Raltegravir to Prevent Mother-to-Child Transmission of HIV in Infected Pregnant Women

We conducted a retrospective study in a general hospital in Buenos Aires, Argentina (2009-2015) aimed at evaluating outcomes in HIV-infected pregnant women (HIPW), who were prescribed raltegravir (RAL)-containing antiretroviral therapy (ART). A total of 239 HIPW were enrolled in our study; among them 31 received RAL (12.9%) at different clinical stages: i) intensification (INS): addition of RAL to current ART because of detectable antepartum viral load, 13 (41.9%); ii) late presenter (LP): standard ART + RAL as fourth drug, 15 (48.4%); iii) treatment of resistant-HIV: 3 (9.7%). Median gestational age at RAL initiation was 34 weeks and median exposure was 30 days. In INS-group, median viral load (VL) decrease was 1.48 log10. In LP-group, median VL decline was 2.15 log10. No clinical adverse events or maternal intolerance attributable to RAL were observed. Elective cesarean section was done in 51.7%; mild elevation of transaminases was observed in 35% of neonates. No vertical transmission was documented.

Critical Review: Review of the Efficacy, Safety, and Pharmacokinetics of Raltegravir in Pregnancy

Raltegravir was previously considered an alternative antiretroviral in pregnancy because of limited data, but recent pregnancy guidelines recommend raltegravir as a preferred integrase treatment option. Data from published articles and preliminary meeting reports between 2001 and July 2015 are reviewed. The literature includes a total of 278 maternal-infant pairs who received raltegravir during pregnancy. The standard raltegravir dose seems safe and effective in preventing mother-to-child transmission in late pregnancy presenters with unknown or unsuppressed viral load, or in multidrug resistance. Viral decay was rapid allowing most women to deliver at undetectable viral levels. Raltegravir was well tolerated, with the exception of a few cases of transient increases in maternal transaminases. No infant adverse effect was consistently reported. Existing data support the use of raltegravir in antiretroviral-naive and experienced pregnant women.

Thai national guidelines for the prevention of mother-to-child transmission of human immunodeficiency virus 2017

BACKGROUND

Thailand has made progress in reducing perinatal HIV transmission rates to levels that meet the World Health Organization targets for so-called "elimination" (<2%) of mother-to-child transmission (MTCT).

OBJECTIVES

To highlight the Thailand National Guidelines on HIV/AIDS Treatment Prevention Working Group issued a new version of its National Prevention of MTCT guidelines in March 2017 aimed to reduce MTCT rate to <1% by 2020.

DISCUSSION OF GUIDELINES

The guidelines include recommending initiation of antepartum antiretroviral therapy (ART) containing tenofovir disoproxil fumarate (TDF) plus lamivudine (3TC)/emtricitabine (FTC) plus efavirenz regardless of CD4 cell count as soon as HIV is diagnosed for ART naïve HIV-infected pregnant women. An alternative regimen is TDF or zidovudine (AZT) plus 3TC/FTC plus lopinavir/ritonavir (LPV/r) for HIV-infected pregnant women suspected resistant to non-nucleoside reverse transcriptase inhibitors. Treatment should be started immediately irrespective of gestational age and continued after delivery for life. Raltegravir is recommended in addition to the ART regimen for HIV-infected pregnant women who present late (gestational age (GA) ≥32 weeks) or those who have a viral load (VL) >1000 copies/mL at GA ≥32 weeks. HIV-infected pregnant women who conceive while receiving ART should continue their treatment regimen during pregnancy. HIV-infected pregnant women who present in labor and are not receiving ART should receive single-dose nevirapine immediately along with oral AZT, and continue ART for life. Infants born to HIV-infected mothers are categorized as high or standard risk for MTCT. High MTCT risk is defined as an infant whose mother has a viral load (VL) > 50 copies/mL at GA > 36 weeks or has received ART <12 weeks before delivery, or has poor ART adherence. These infants should be started on AZT plus 3TC plus NVP for 6 weeks after delivery. Infants with standard MTCT risk should receive AZT for 4 weeks. Formula feeding exclusively is recommended for all HIV-exposed infants.

Integrase inhibitors in late pregnancy and rapid HIV viral load reduction

BACKGROUND

Minimizing time to HIV viral suppression is critical in pregnancy. Integrase strand transfer inhibitors (INSTIs), like raltegravir, are known to rapidly suppress plasma HIV RNA in nonpregnant adults. There are limited data in pregnant women.

OBJECTIVE

We describe time to clinically relevant reduction in HIV RNA in pregnant women using INSTI-containing and non-INSTI-containing antiretroviral therapy (ART) options.

STUDY DESIGN

We conducted a retrospective cohort study of pregnant HIV-infected women in the United States from 2009 through 2015. We included women who initiated ART, intensified their regimen, or switched to a new regimen due to detectable viremia (HIV RNA >40 copies/mL) at ≥20 weeks gestation. Among women with a baseline HIV RNA permitting 1-log reduction, we estimated time to 1-log RNA reduction using the Kaplan-Meier estimator comparing women starting/adding an INSTI in their regimen vs other ART. To compare groups with similar follow-up time, we also conducted a subgroup analysis limited to women with ≤14 days between baseline and follow-up RNA data.

RESULTS

This study describes 101 HIV-infected pregnant women from 11 US clinics. In all, 75% (76/101) of women were not taking ART at baseline; 24 were taking non-INSTI containing ART, and 1 received zidovudine monotherapy. In all, 39% (39/101) of women started an INSTI-containing regimen or added an INSTI to their ART regimen. Among 90 women with a baseline HIV RNA permitting 1-log reduction, the median time to 1-log RNA reduction was 8 days (interquartile range [IQR], 7-14) in the INSTI group vs 35 days (IQR, 20-53) in the non-INSTI ART group (P < .01). In a subgroup of 39 women with first and last RNA measurements ≤14 days apart, median time to 1-log reduction was 7 days (IQR, 6-10) in the INSTI group vs 11 days (IQR, 10-14) in the non-INSTI group (P < .01).

CONCLUSION

ART that includes INSTIs appears to induce more rapid viral suppression than other ART regimens in pregnancy. Inclusion of an INSTI may play a role in optimal reduction of HIV RNA for HIV-infected pregnant women presenting late to care or failing initial therapy. Larger studies are urgently needed to assess the safety and effectiveness of this approach.

An HIV-infected Pregnant Woman Treated with the Long-term Administration of Antiretroviral Therapy Including Raltegravir

A 27-year-old HIV-infected pregnant Japanese woman was admitted to our hospital at gestational week 14. The patient's HIV viral load was 71,000 copies/mL, and her CD4 cell count was 147 cells/mm(3). Zidovudine, lamivudine, and lopinavir/ritonavir were administered at gestational week 18. Because the viral load increased to 222,000 copies/mL at the initiation of antiretroviral therapy, we added raltegravir. The decrease in the viral load was satisfactory, and a caesarean delivery was performed. Although the plasma concentration of raltegravir in the neonate was significantly high (2,482 ng/mL), no adverse event was confirmed. There was no evidence of the mother-to-child transmission of HIV.

A case series of third-trimester raltegravir initiation: Impact on maternal HIV-1 viral load and obstetrical outcomes

OBJECTIVE

To describe the impact of initiating raltegravir (RAL)-containing combination antiretroviral therapy (cART) regimens on HIV viral load (VL) in pregnant women who have high or suboptimal VL suppression late in pregnancy.

METHODS

HIV-infected pregnant women who started RAL-containing cART after 28 weeks' gestation from 2007 to 2013 were identified in two university hospital centres.

RESULTS AND DISCUSSION

Eleven HIV-infected women started RAL at a median gestational age of 35.7 weeks (range 31.1 to 38.0 weeks). Indications for RAL initiation were late presentation in pregnancy (n=4) and suboptimal VL suppression secondary to poor adherence or viral resistance (n=7). Mean VL at the time of RAL initiation was 73,959 copies/mL (range <40 to 523,975 copies/mL). Patients received RAL for a median of 20 days (range one to 71 days). The mean decline in VL from the time of RAL initiation to delivery was 1.93 log, excluding one patient who received only one RAL dose and one patient with undetectable VL at the time of RAL initiation. After eight days on RAL, 50% of the women achieved a VL <1000 copies/mL (the threshold for recommended Caesarean section to reduce the risk for perinatal transmission). There were no cases of perinatal HIV transmission.

CONCLUSION

The present study provides preliminary data to support the use of RAL-containing cART to expedite HIV-1 VL reduction in women who have a high VL or suboptimal VL suppression late in pregnancy, and to decrease the risk of HIV perinatal transmission while avoiding Caesarean section. Further assessment of RAL safety during pregnancy is warranted.

Raltegravir pharmacokinetics during pregnancy

OBJECTIVE

We evaluated the pharmacokinetics (PK) of raltegravir in HIV-infected women during pregnancy and postpartum.

METHODS

International Maternal Pediatric Adolescent AIDS Clinical Trials 1026s is an ongoing prospective study of antiretroviral PK during pregnancy (NCT00042289). Women receiving 400 mg raltegravir twice daily in combination antiretroviral therapy had intensive steady-state 12-hour PK profiles performed during pregnancy and at 6- to 12-week postpartum. Targets were trough concentration above 0.035 μg/mL, the estimated 10th percentile in nonpregnant historical controls.

RESULTS

Median raltegravir area under the curve was 6.6 μg·h/mL for second trimester (n = 16), 5.4 μg·h/mL for third trimester (n = 41), and 11.6 μg·h/mL postpartum (n = 38) (P = 0.03 postpartum vs second trimester, P = 0.001 pp vs third trimester). Trough concentrations were above the target in 69%, 80%, and 79% of second trimester, third trimester, and postpartum subjects, respectively, with wide variability (<0.010-0.917 μg/mL), and no significant difference between third trimester and postpartum trough concentrations was detected. The median ratio of cord blood/maternal raltegravir concentrations was 1.5. HIV RNA levels were <400 copies per milliliter in 92% of women at delivery. Adverse events included elevated liver transaminases in 1 woman and vomiting in 1. All infants with known status are HIV uninfected.

CONCLUSIONS

Median raltegravir area under the curve was reduced by approximately 50% during pregnancy; trough concentrations were frequently below target both during late pregnancy and postpartum. Raltegravir readily crossed the placenta. High rates of viral suppression at delivery and the lack of a clear relationship between raltegravir concentration and virologic effect in nonpregnant adults suggest that despite the decreased exposure during pregnancy, a higher dose is not necessary.

Pharmacological considerations on the use of antiretrovirals in pregnancy

PURPOSE OF REVIEW

Treatment with combination antiretroviral therapy during pregnancy reduces the chance of mother to child transmission of HIV. Physiological changes during pregnancy can lead to lower exposure to antiretrovirals, possibly resulting in virological failure. For most antiretrovirals, data on exposure during pregnancy and transplacental passage are limited. This review summarizes the most recent information on pharmacokinetics (including transplacental passage), efficacy, as well as the safety of antiretrovirals during pregnancy.

RECENT FINDINGS

Intensive-sampling pharmacokinetic studies as well as observational studies using sparse sampling were performed to explore the exposure to antiretrovirals during pregnancy. Transplacental passage, efficacy (viral load at delivery and infection status of the newborn) and safety information were evaluated for several antiretrovirals.

SUMMARY

For most nucleoside/nucleotide reverse transcriptase inhibitors and protease inhibitors, recent research shows a decreased exposure during pregnancy. However, the advantage of a general dose increase during pregnancy still remains unclear. For newer compounds and efavirenz, limited or no data on pharmacokinetics during pregnancy or transplacentally are available, while the mechanisms of transplacental passage also remain unknown. For safety reasons, it will be important to monitor pregnancy outcomes in resource-limited settings during the implementation of the WHO guidelines (including the use of efavirenz during pregnancy).