Comparative effectiveness of risk mitigation strategies to prevent fetal exposure to mycophenolate

Teratogenic Risk Impact and Mitigation (TRIM): Study Protocol for the Development of a Decision Support Tool to Prioritize Medications for Risk Mitigation

INTRODUCTION

Preventing prenatal exposure to teratogenic medications is an important goal of regulatory risk mitigation efforts. In the USA, as of March 2024, 11 teratogenic medications have a required Risk Evaluation and Mitigation Strategy (REMS) program. It is unclear whether these programs target those medications with the most significant impact on public health and adverse pregnancy outcomes.

OBJECTIVES

This study aims to develop an innovative decision support tool that uses explicit, quantifiable criteria to facilitate prioritization of teratogenic medications for risk mitigation strategies.

METHODS

The Teratogenic Risk Impact and Mitigation (TRIM) decision support tool will be developed by a national panel via a modified Delphi approach to define measurable criteria, and a multi-criteria decision analysis to estimate criteria weights within a discrete choice experiment. The TRIM scores will then be calculated for 12 teratogenic drugs with active or eliminated REMS programs and for 12 teratogenic drugs without REMS. These drugs will be identified based on highest prenatal exposure prevalence in claims data of privately and publicly insured individuals. Data for the TRIM criteria levels for these 24 drugs will be identified from evidence searches and ad hoc analyses of the same claims data.

CONCLUSIONS

Teratogenic Risk Impact and Mitigation is intended to inform regulatory decision making about the need for risk mitigation programs for teratogenic medications by providing explicit, quantifiable, evidence-based criteria. The TRIM scores of 24 teratogenic drugs may provide benchmarks for considering REMS for marketed and new teratogenic medications.

Assessment of the implementation of risk minimization measures for bosentan: a retrospective study

BACKGROUND

Bosentan is associated with adverse hepatic effects. To minimize such risk, regulators implemented risk minimization measures (RMMs), including testing for liver injury biomarkers (alanine and aspartate transaminase and bilirubin) prior to therapy initiation and monthly throughout therapy. This study aimed to examine the adherence to hepatic monitoring requirements.

RESEARCH DESIGN AND METHODS

This retrospective cohort study collected data about bosentan new-users from the Real-world Evidence Research Network from 2016 to 2022. We ascertained hepatic tests from laboratory files. Adherence to RMM definition was performing the required tests within 90 days before initiation and categorized adherence to monthly testing requirement based on the expected number of tests throughout therapy as low (<50%), moderate (50-74%), and high (≥75%).

RESULTS

One hundred patients entered the study cohort and 71% were females, with a median age of 25 years. Adherence to testing prior to bosentan initiation was 60%. Adherence to monthly testing was low in the majority of patients (58.2%).

CONCLUSIONS

Adherence to bosentan RMMs relevant to minimizing risk of hepatotoxicity either before starting or throughout therapy was low. Our findings could be used as a baseline for monitoring trends in implementation of RMMs over time or to compare performance of various minimization strategies.

Prenatal Exposure to Valproic Acid Across Various Indications for Use

Importance

Teratogenic outcomes associated with valproic acid use represent a substantial concern for persons of childbearing age. Regulatory agencies worldwide have enhanced warnings or implemented risk minimization programs to reduce exposure during pregnancy.

Objectives

To determine pregnancy rates during valproic acid use and concomitant contraception use across indications.

Design, Setting, and Participants

This retrospective cohort study used data from the Merative MarketScan commercial claims databases from January 1, 2005, to December 31, 2020, to identify female patients aged 12 to 44 years who initiated valproic acid treatment and had continuous insurance enrollment 6 months before initiation and 9 months after treatment end. A treatment episode included consecutive prescription fills that occurred within 7 days from the end of the days' supply of the previous dispensing. Data were analyzed from March 1 to September 10, 2023.

Main Outcomes and Measures

Treatment episodes were categorized by inferred indication using diagnoses preceding treatment initiation, including epilepsy, migraine or headache, mood disorders, and unknown or off-label uses. Pregnancy incidence rate ratios (IRRs) were calculated and were adjusted for age and calendar year. Contraceptive use (prescription contraceptives, intrauterine devices, and implants) during treatment was examined.

Results

The cohort included 165 772 valproic acid treatment episodes among 69 390 women (mean [SD] age, 29.8 [10.0] years). Mood disorders (42.5%) were the most common indication, followed by migraine or headache (20.1%), with epilepsy playing a minor role (14.9%). Pregnancy incidence rates during valproic acid use remained unchanged, with a rate of 1.74 (95% CI, 1.14-2.53) per 100 person-years in 2005 and a rate of 1.90 (95% CI, 1.16-3.12) per 100 person-years in 2019. Compared with epilepsy, pregnancy rates were more than double for mood disorder (IRR, 2.16 [95% CI, 1.93-2.42]) and migraine or headache (IRR, 2.01 [95% CI, 1.92-2.09]). Few treatment episodes coincided with contraceptive use (37 012 [22.3%]), and oral dosage forms were the most common (27 069 [73.1%]).

Conclusions and Relevance

In this cohort study of patients of childbearing age who used valproic acid, pregnancy rates during valproic acid use did not decrease despite enhanced US Food and Drug Administration safety communications, and contraception use remained low. Patients with migraine and mood disorders accounted for the largest proportion of valproic acid use and had the highest pregnancy rates, while patients with epilepsy had the lowest. These findings suggest a need to enhance efforts to mitigate prenatal exposure to valproic acid, especially for indications where the risk of use during pregnancy outweighs the benefit.

Prenatal Care Initiation and Exposure to Teratogenic Medications

Importance

With new legal abortion restrictions, timing of prenatal care initiation is critical to allow for discussion of reproductive options among pregnancies exposed to teratogenic medications.

Objective

To investigate the prevalence of prenatal exposure to teratogenic medications and prenatal care initiation across gestational weeks.

Design, Setting, and Participants

This descriptive, population-based cross-sectional study used health encounter data from a national sample of individuals with employer-sponsored health insurance. A validated algorithm identified pregnancies among persons identifying as female that ended with a live or nonlive outcome between January 2017 and December 2019. Data were analyzed from December 2022 to December 2023.

Exposures

Prenatal exposure to any of 137 teratogenic medications, measured via pharmacy and medical claims. Measurement of prenatal care initiation was adapted from the Children's Health Care Quality Measures.

Main Outcomes and Measures

Prevalence of prenatal exposure to teratogens and prenatal care initiation by gestational week. Timing of prenatal teratogenic exposure was compared with timing of prenatal care initiation and legal abortion cutoffs.

Results

Among 639 994 pregnancies, 472 472 (73.8%; 95% CI, 73.7%-73.9%) had a live delivery (mean [SD] age, 30.9 [5.4] years) and 167 522 (26.2%; 95% CI, 26.1%-26.3%) had a nonlive outcome (mean [SD] age, 31.6 [6.4] years). Of pregnancies with live deliveries, 5.8% (95% CI, 5.7%-5.8%) were exposed to teratogenic medications compared with 3.1% (95% CI, 3.0%-3.2%) with nonlive outcomes. Median time to prenatal care was 56 days (IQR, 44-70 days). By 6 weeks' gestation, 8186 pregnancies had been exposed to teratogenic medications (25.2% [95% CI, 24.7%-25.7%] of pregnancies exposed at any time during gestation; 1.3% [95% CI, 1.3%-1.3%] of all pregnancies); in 6877 (84.0%; 95% CI, 83.2%-84.8%), prenatal care was initiated after 6 weeks or not at all. By 15 weeks, teratogenic exposures had occurred for 48.9% (95% CI, 48.4%-49.5%) of all teratogen-exposed pregnancies (2.5% [2.4-2.5] of all pregnancies); prenatal care initiation occurred after 15 weeks for 1810 (16.8%; 95% CI, 16.1%-17.5%) with live deliveries and 2975 (58.3%; 95% CI, 56.9%-59.6%) with nonlive outcomes. Teratogenic medications most used within the first 15 gestational weeks among live deliveries included antiinfectives (eg, fluconazole), anticonvulsants (eg, valproate), antihypertensives (eg, lisinopril), and immunomodulators (eg, mycophenolate). For nonlive deliveries, most antihypertensives were replaced by vitamin A derivatives.

Conclusions and Relevance

In this cross-sectional study, most exposures to teratogenic medications occurred in early pregnancy and before prenatal care initiation, precluding prenatal risk-benefit assessments. Prenatal care commonly occurred after strict legal abortion cutoffs, prohibiting consideration of pregnancy termination if concerns about teratogenic effects arose.

Common teratogenic medication exposures-a population-based study of pregnancies in the United States

BACKGROUND

Risk mitigation for most teratogenic medications relies on risk communication via drug label, and prenatal exposures remain common. Information on the types of and risk factors for prenatal exposures to medications with teratogenic risk can guide strategies to reduce exposure.

OBJECTIVE

This study aimed to identify medications with known or potential teratogenic risk commonly used during pregnancy among privately insured persons.

STUDY DESIGN

We used the Merative™ MarketScan® Commercial Database to identify pregnancies with live or nonlive (ectopic pregnancies, spontaneous and elective abortions, stillbirths) outcomes among persons aged 12 to 55 years from 2011 to 2018. Start/end dates of medication exposure and pregnancy outcomes were identified via an adapted algorithm based on validation studies. We required continuous health plan enrollment from 90 days before conception until 30 days after the pregnancy end date. Medications with known or potential teratogenic risk were selected from TERIS (Teratogen Information System) and drug monographs based on the level of risk and quality of evidence (138 with known and 60 with potential risk). We defined prenatal exposure on the basis of ≥1 outpatient pharmacy claim or medical encounter for medication administration during target pregnancy periods considering medication risk profiles (eg, risk only in the first trimester or at a certain dose threshold). Sex hormones and hormone analogs, and abortion and postpartum/abortion hemorrhage treatments were not considered as teratogenic medications because of challenges in separating pregnancy-related indications, nor were opioids (because of complex risk-benefit considerations) or antiobesity medications if their only teratogenic mechanism was weight loss.

RESULTS

Among all pregnancies, the 10 medications with known teratogenic risk and the highest prenatal exposures were sulfamethoxazole/trimethoprim (1988 per 100,000 pregnancy-years), high-dose fluconazole (1248), topiramate (351), lisinopril (144), warfarin (57), losartan (56), carbamazepine (50), valproate (49), vedolizumab (28 since 2015), and valsartan (25). Prevalence of exposure to sulfamethoxazole/trimethoprim decreased from 2346 to 1453 per 100,000 pregnancy-years from 2011 to 2018, but prevalence of exposure to vedolizumab increased 6-fold since its approval in 2015. Prenatal exposures in the first trimester were higher among nonlive pregnancies than among live-birth pregnancies, with the largest difference observed for warfarin (nonlive 370 vs live birth 78), followed by valproate (258 vs 86) and topiramate (1728 vs 674). Prenatal exposures to medications with potential teratogenic risk were most prevalent for low-dose fluconazole (6495), metoprolol (1325), and atenolol (448). The largest first-trimester exposure differences between nonlive and live-birth pregnancies were observed for lithium (242 vs 89), gabapentin (1639 vs 653), and duloxetine (1914 vs 860). Steady increases in hydralazine and gabapentin exposures were observed during the study years, whereas atenolol exposure decreased (561 to 280).

CONCLUSION

Several medications with teratogenic risk for which there are potentially safer alternatives continue to be used during pregnancy. The fluctuating rates of prenatal exposure observed for select teratogenic medications suggest that regular reevaluation of risk mitigation strategies is needed. Future research focusing on understanding the clinical context of medication use is necessary to develop effective strategies for reducing exposures to medications with teratogenic risk during pregnancy.

Assessment of the Risk Evaluation and Mitigation Strategy (REMS) for Phentermine-Topiramate to Prevent Exposure During Pregnancy

BACKGROUND

The U.S. Food and Drug Administration approved phentermine-topiramate for obesity in 2012 and required a Risk Evaluation and Mitigation Strategy (REMS) to prevent prenatal exposure. No such requirement was introduced for topiramate.

OBJECTIVE

To evaluate the rate of prenatal exposure, contraceptive use, and pregnancy testing among patients with phentermine-topiramate compared with topiramate or other antiobesity medications (AOMs).

DESIGN

Retrospective cohort study.

SETTING

Nationwide health insurance claims database.

PARTICIPANTS

Females aged 12 to 55 years with no infertility diagnosis or sterilization procedure. Patients with other indications for topiramate were excluded to identify a cohort that was likely treated for obesity.

MEASUREMENTS

Patients initiated use of phentermine-topiramate, topiramate, or an AOM (liraglutide, lorcaserin, or bupropion-naltrexone). Pregnancy at treatment initiation, conception during treatment, contraceptive use, and pregnancy testing outcomes were ascertained. Measurable confounders were adjusted for, and extensive sensitivity analyses were done.

RESULTS

A total of 156 280 treatment episodes were observed. Adjusted prevalence of pregnancy at treatment initiation was 0.9 versus 1.6 per 1000 episodes (prevalence ratio, 0.54 [95% CI, 0.31 to 0.95]) for phentermine-topiramate versus topiramate. The incidence rate of conception during treatment was 9.1 versus 15.0 per 1000 person-years (rate ratio, 0.61 [CI, 0.40 to 0.91]) for phentermine-topiramate versus topiramate. Both outcomes were similarly lower for phentermine-topiramate compared with AOM. Prenatal exposure was marginally lower in topiramate users compared with AOM users. Approximately 20% of patients in all cohorts had at least 50% of treatment days covered by contraceptives. Few patients had pregnancy tests before treatment (≤5%), but this was more common among phentermine-topiramate users.

LIMITATIONS

Outcome misclassification; unmeasured confounding due to lack of prescriber data to account for possible clustering and spillover effects.

CONCLUSION

Prenatal exposure seemed to be significantly lower among phentermine-topiramate users under the REMS. Pregnancy testing and contraceptive use appeared to be inadequate for all groups, which deserves attention to prevent the remaining potential exposures.

PRIMARY FUNDING SOURCE

None.

Analysis of risk evaluation and mitigation strategies for teratogenic drugs: Variation in primary and secondary prevention measures

In an analysis of risk evaluation and mitigation strategies for teratogenic drugs, Ameet Sarpatwari, Beatrice Brown and Aaron Kesselheim explore the variation in primary and secondary prevention measures.

Reproductive Health Care for Female Adolescents Prescribed Mycophenolate at a Children's Hospital: A 10-Year Retrospective Cohort Study

OBJECTIVES

To describe female adolescents' reproductive health needs and subspecialists' teratogenic counseling at initiation of mycophenolate as well as use of reproductive health care and contraception after mycophenolate initiation.

STUDY DESIGN

We searched health records for female patients aged 12-20 years prescribed mycophenolate from 2010 to 2019. We included 125 subjects, 72 with systemic lupus erythematosus, 27 with transplants, and 26 with other conditions. We reviewed all encounters with pediatric subspecialists and reproductive clinicians. We recorded counseling by subspecialists at mycophenolate initiation and compared rates pre- and post-Risk Evaluation and Mitigation Strategy (REMS). We recorded subjects' menstrual, sexual and pregnancy history, type of first highly effective contraceptive method used, and duration of use over the decade.

RESULTS

At mycophenolate initiation, mean age was 16.8 ± 2.6 years; 72% Hispanic/Latina or Black. In total, 80% were postmenarchal, 28% ever had sex, 18% ever had a reproductive health care visit, 14% used highly effective contraception, and 7% were ever pregnant. Post-REMS vs pre-REMS, we found greater rates of counseling for teratogenicity (68% vs 32%, P < .001) and contraception (62% vs 32%, P < .001) and pregnancy testing (51% vs 24%, P < .01). Over the mean 4.9 ± 3.3 years' follow-up, 56% ever had sex; 59% ever attended a reproductive health care visit; 38% used highly effective contraception; and 10% had a pregnancy.

CONCLUSIONS

Adolescents prescribed mycophenolate have ongoing unmet reproductive health care needs. Although many are sexually active, fewer use effective contraception. Teratogenicity counseling rates improved over the decade but not rates of referral for reproductive health care.

Safeguarding children and young people requiring kidney replacement therapy: challenges and potential opportunities

Kidney replacement therapy (KRT) makes considerable physical and psychological demands on children, young people and their families. The impact can be wide-ranging, affecting education, employment, mental health, finances and relationships for both child and caregiver. It is vitally important for those working with these families to recognise the psychosocial challenges they face and to know the range of interventions available. This article explores the psychosocial impact of KRT, considering opportunities to minimise risk and optimise outcomes for children, young people and their families.

Prenatal exposure to teratogenic medications in the era of Risk Evaluation and Mitigation Strategies

BACKGROUND

Prevention of prenatal exposures to teratogenic drugs is a significant clinical and public health concern. With the enactment of the US Food and Drug Administration Amendments Act in 2007, the US Food and Drug Administration has begun to require manufacturers to implement Risk Evaluation and Mitigation Strategies to prevent prenatal exposures. Among 12 risk evaluation and mitigation strategy drugs, several had predecessor risk mitigation plans (eg, isotretinoin) and some were newly required (eg, mycophenolate). Only a small proportion of teratogenic drugs are currently subject to Risk Evaluation and Mitigation Strategies, and the extent of prenatal exposure to the universe of teratogenic drugs compared with drugs subject to Risk Evaluation and Mitigation Strategies is unknown. Moreover, the effectiveness of such advanced risk mitigation programs in preventing prenatal exposure is not clear.

OBJECTIVE

This study aimed to characterize the epidemiology of prenatal exposures to definite and potential teratogens during the risk evaluation and mitigation strategy era.

STUDY DESIGN

We constructed a time-series of pregnancies identified from a national private insurance claims database (IBM MarketScan) to estimate prenatal exposures to teratogenic drugs (2006-2017). Pregnancy outcomes, gestational age, and the onset of pregnancy were determined with previously validated algorithms. The Teratology Information Service and Clinical Pharmacology databases were used to identify drugs with definite (n=141) or potential (n=65) teratogenic effects, and drugs with debatable risks such as benzodiazepines, statins, tetracyclines, sex hormones, infertility treatments, and gonadotropin-releasing hormone analogs were excluded. We defined prenatal exposure as ≥1 prescription fill or medical encounter involving administration of drugs with a definite teratogenic risk (including 12 for which there is a "current or discontinued" risk evaluation and mitigation strategy) or a potential teratogenic risk. We evaluated secular trends and modeled the effects of age, preconception exposure, and state healthcare quality rankings on prenatal exposure, adjusting for demographic factors and clinical conditions.

RESULTS

The cohort included 3,445,612 pregnancies (2,532,444 live deliveries). Prenatal exposures to definite teratogens decreased slightly during the study years from 1.86 to 1.24 per 100 pregnancies between 2006 and 2017, whereas exposure increased for potential teratogens from 3.40% to 5.33%. Prenatal exposure prevalences were higher during the first trimester and for pregnancies that ended in nonlive outcomes. Drugs subject to Risk Evaluation and Mitigation Strategies had low background utilization and contributed to a small proportion of prenatal exposures (15.1 per 100,000 pregnancies). We also observed fewer prenatal exposures to risk evaluation and mitigation strategy drugs among women of childbearing age who used these treatments (0.14% vs 0.36% for any definite teratogen). Age extremes and low state-level healthcare quality rankings were independent predictors of prenatal exposure.

CONCLUSION

Fetuses in more than 1 in 16 pregnancies continued to be exposed to teratogenic drugs during the past decade. Drugs with Risk Evaluation and Mitigation Strategies imposed a small burden of prenatal exposure because of the low background utilization rates and lower pregnancy prevalence among women of childbearing age who used these drugs. Although the declining exposure rates to teratogenic drugs with definite risk are encouraging, the rising prenatal exposure to drugs with potential risk calls for more assessments. Future research is needed to elucidate the health outcomes of fetuses exposed to potential risk drugs, understand the effectiveness of risk evaluation and mitigation strategy programs, and prioritize teratogenic drugs for advanced risk mitigation.

A Pharmacoepidemiologic Approach to Evaluate Real-world Effectiveness of Hormonal Contraceptives in the Presence of Drug-drug Interactions

Accurate estimation of conception is critical in the assessment of the effects of drugs used during pregnancy or to prevent pregnancy. In a novel application, we studied the effectiveness of oral contraceptives (OCs), where misclassification of conception relative to OC exposure may obscure effect estimates.

Impact of the Transition from ICD-9-CM to ICD-10-CM on the Identification of Pregnancy Episodes in US Health Insurance Claims Data

Background

Before October 2015, pregnancy cohorts assembled from US health insurance claims have relied on medical encounters with International Classification of Diseases-ninth revision-clinical modification (ICD-9-CM) codes. We aimed to extend existing pregnancy identification algorithms into the ICD-10-CM era and evaluate performance.

Methods

We used national private insurance claims data (2005-2018) to develop and test a pregnancy identification algorithm. We considered validated ICD-9-CM diagnosis and procedure codes that identify medical encounters for live birth, stillbirth, ectopic pregnancy, abortions, and prenatal screening to identify pregnancies. We then mapped these codes to the ICD-10-CM system using general equivalent mapping tools and reconciled outputs with literature and expert opinion. Both versions were applied to the respective coding period to identify pregnancies. We required 45 weeks of health plan enrollment from estimated conception to ensure the capture of all pregnancy endpoints.

Results

We identified 7,060,675 pregnancy episodes, of which 50.1% met insurance enrollment requirements. Live-born deliveries comprised the majority (76.5%) of episodes, followed by abortions (20.3%). The annual prevalence for all pregnancy types was stable across the ICD transition period except for postterm pregnancies, which increased from 0.5% to 3.4%. We observed that ICD codes indicating gestational age were available for 86.8% of live-born deliveries in the ICD-10 era compared to 23.5% in the ICD-9 era. Patterns of prenatal tests remained stable across the transition period.

Conclusion

Translation of existing ICD-9-CM pregnancy algorithms into ICD-10-CM codes provided reasonable consistency in identifying pregnancy episodes across the ICD transition period. New codes for gestational age can potentially improve the precision of conception estimates and minimize measurement biases.

Risk of pregnancy loss in patients exposed to mycophenolate compared to azathioprine: A retrospective cohort study

PURPOSE

To evaluate the relative risk of pregnancy loss associated with mycophenolate (MPA) vs azathioprine (AZA) use.

METHODS

We conducted a retrospective cohort study using the IBM MarketScan Research Databases (2005-2015). Patients with ≥1 MPA or AZA prescription claim during the first trimester were included. The study outcome was pregnancy loss (spontaneous abortion or stillbirth). Potential confounders included age, drug indications, comorbidities, other teratogenic medication use, and gestational age at first MPA or AZA prescription fill. The risk for pregnancy loss was estimated using a generalized estimating equation model with stabilized inverse probability of treatment weighting. In sensitivity analyses, we varied the exposure definition, outcome definition, and the analytical method.

RESULTS

Among 111 pregnancies exposed to MPA, 55 resulted in pregnancy loss (49.5%). Among 471 pregnancies exposed to AZA, 113 had pregnancy loss (24.0%). The unadjusted relative risk for pregnancy loss was 2.0 (95% CI 1.6, 2.6), and the adjusted relative risk was 1.9 (95% CI, 1.6, 2.3) compared to AZA. Relative risk estimates were stable in all sensitivity analyses.

CONCLUSION

Exposure to MPA during early pregnancy was associated with a 2-fold increase in pregnancy loss risk.