Effects of natalizumab, an α4 integrin inhibitor, on the development of Hartley guinea pigs

Influence of Pregnancy in Multiple Sclerosis and Impact of Disease-Modifying Therapies

Purpose of this Review: This article is a systematic review on the influence pregnancy has on multiple sclerosis and the resulting impact of disease-modifying therapies.

Findings: Multiple sclerosis predominantly affects young women with a clinical onset most often during the child-bearing age. The impact of multiple sclerosis and disease-modifying therapies on fertility, pregnancy, fetal outcome, and breastfeeding is a pivotal topic when it comes to clinical practice. The introduction of disease-modifying therapies has changed not only the natural history of the disease but also the perspective of pregnancy in women with multiple sclerosis. Family planning requires careful consideration, especially because many disease-modifying drugs are contraindicated during pregnancy. In this article, we review current evidence collected from published literature and drug-specific pregnancy registers on the use of disease-modifying therapies. Additionally, we discuss safety profiles for each drug and correlate them to both risk for the exposed fetus and risk for the mothers interrupting treatments when seeking pregnancy.

Erythropoietin therapy in a case of neonatal anemia after exposure to natalizumab throughout pregnancy

Background

Natalizumab is a monoclonal antibody approved for the treatment of patients with relapsing-remitting multiple sclerosis. According to the current clinical recommendations, its use during pregnancy should be carefully evaluated only in women with highly active disease who plan a pregnancy or have an unplanned pregnancy, after accurate counseling about eventual maternal disease relapse due to therapy suspension.

Case presentation

This brief case report describes a case of documented anemia that we observed in a newborn whose mother with relapsing-remitting multiple sclerosis was treated with an extended dosing protocol of natalizumab throughout pregnancy. The newborn received the infusion of erythropoietin every seven days from the fortieth day of life; subsequently, the status of anemia underwent clinical resolution.

Conclusions

This case report confirmed that natalizumab can cause disorders of hematopoiesis, including anemia, thrombocytopenia, or pancytopenia, in newborns of patients treated during pregnancy. A multidisciplinary team, including experienced pediatricians and pediatric hematologists, has a critical role in managing newborns delivered by women, being treated with natalizumab for treating relapsing-remitting multiple sclerosis during pregnancy.

Challenges of non-clinical safety testing for biologics: A Report of the 9th BioSafe European Annual General Membership Meeting

New challenges and other topics in non-clinical safety testing of biotherapeutics were presented and discussed at the nineth European BioSafe Annual General Membership meeting in November 2019. The session topics were selected by European BioSafe organization committee members based on recent company achievements, agency interactions and new data obtained in the non-clinical safety testing of biotherapeutics, for which data sharing would be of interest and considered as valuable information. The presented session topics ranged from strategies of in vitro testing, immunogenicity prediction, bioimaging, and developmental and reproductive toxicology (DART) assessments to first-in-human (FIH) dose prediction and bioanalytical challenges, reflecting the entire space of different areas of expertise and different molecular modalities. During the 9th meeting of the European BioSafe members, the following topics were presented and discussed in 6 main sessions (with 3 or 4 presentations per session) and in three small group breakout sessions: 1) DART assessment with biotherapeutics: what did we learn and where to go?; 2) Non-animal testing strategies; 3) Seeing is believing: new frontiers in imaging; 4) Predicting immunogenicity during early drug development: hope or despair?; 5) Challenges in FIH dose projections; and 6) Non-canonical biologics formats: challenges in bioanalytics, PKPD and biotransformation for complex biologics formats. Small group breakout sessions were organized for team discussion about 3 specific topics: 1) Testing of cellular immune function in vitro and in vivo; 2) MABEL approach (toxicology and pharmacokinetic perspective); and 3) mRNA treatments. This workshop report presents the sessions and discussions at the meeting.

Men With Inflammatory Bowel Disease: Sexual Function, Fertility, Medication Safety, and Prostate Cancer

Half of patients with inflammatory bowel disease (IBD) are men, yet less attention has been focused on their sexual issues despite higher rates of sexual dysfunction and infertility than the general population. Depression and IBD disease activity are the most consistently reported risk factor for sexual dysfunction among men with IBD. Methotrexate and sulfasalazine have been rarely associated with impotence. Sulfasalazine reversibly reduces male fertility. No other medications used in IBD significantly affect fertility in humans. There is no increase in adverse fetal outcomes among offspring of fathers with IBD. Patients with IBD seem to be at a higher risk for prostate cancer; therefore, screening as recommended for high-risk patients should be considered.

Maintenance of natalizumab during the first trimester of pregnancy in active multiple sclerosis

BACKGROUND

Planning pregnancy in patients with active multiple sclerosis (MS) is highly challenging because treatment withdrawn may be associated with dramatic disease reactivation.

OBJECTIVE

To compare two strategies for women with active MS who were planning pregnancy: stopping natalizumab (1) at the end of the first trimester and (2) at conception.

METHODS

Standardized strategy for women with active MS was initiated in our department. Maintenance of natalizumab until the end of first trimester was recommended ("secured first trimester" (SFT)). When patients refused, they were advised to continue until conception ("secured conception" (SC)). Predictors of disease activity during pregnancy were assessed.

RESULTS

Forty-six pregnancies were prospectively followed (30 with SFT and 16 with SC). One congenital anomaly occurred in the SC group. The proportions of patients with relapse and disability progression during pregnancy were lower in the SFT than in the SC group (3.6% vs 38.5%, p < 0.005 and 3.6% vs 30.8%, p < 0.05, respectively). Predictors of relapse and disability progression during pregnancy were the time when natalizumab was stopped (conception vs end of first trimester) and the number of relapses during the year before natalizumab.

CONCLUSION

Maintaining natalizumab during the first trimester may reduce the risk of disease reactivation during pregnancy in patients with active MS.

Evaluation of the Developmental Toxicity of Vedolizumab, an α4β7 Receptor Antagonist, in Rabbit and Nonhuman Primate

Vedolizumab, a humanized monoclonal antibody approved for the treatment of adults with moderately to severely active ulcerative colitis or Crohn disease, targets α₄β₇ integrin and selectively blocks gut-specific lymphocyte trafficking. The potential effects of vedolizumab on development were assessed by standard preclinical toxicity studies in rabbits and cynomolgus monkeys. A single infusion of vedolizumab (0, 10, 30, or 100 mg/kg) was administered intravenously to pregnant rabbits on gestational day 7; rabbits were monitored to gestational day 29. Vedolizumab (0, 10, or 100 mg/kg) was administered intravenously every 2 weeks to pregnant cynomolgus monkeys beginning on gestational day 20 with the last dose on gestational day 132 (9 doses total). In rabbits, vedolizumab did not affect maternal net body weight or net gains, gravid uterine weights, or mean maternal food consumption, nor did it affect intrauterine growth or fetal survival. There were also no vedolizumab effects on embryo–fetal development compared to controls. In cynomolgus monkeys, there was no increase in prenatal loss/death or stillbirth and no maternal toxicity associated with vedolizumab. On day 28 postpartum, low levels of vedolizumab were detected in the breast milk of 3 of 11 monkeys in the 100 mg/kg group. No vedolizumab-related effects on the number of infants born, infant development, or animal hematology or clinical chemistry were noted. Administration of vedolizumab to pregnant rabbits and cynomolgus monkeys did not show any potential for maternal or developmental effects.

Natalizumab: Perspectives from the Bench to Bedside

Probably no other disease-modifying drug for multiple sclerosis has a more fascinating story than natalizumab from both the bench to bedside perspective and the postmarketing experience standpoint. Natalizumab is a monoclonal antibody that inhibits the trafficking of lymphocytes from the blood into the central nervous system by blocking the adhesion molecule α4-integrin. Natalizumab was approved as a disease-modifying drug for relapsing remitting multiple sclerosis only 12 years after the discovery of its target molecule-a time line that is rather fast for drug development. However, a few months after its U.S. Food and Drug Administration approval, natalizumab was withdrawn from the market because of an unanticipated complication-progressive multifocal leukoencephalopathy. It was later reinstated with required adherence to a strict monitoring program and incorporation of mitigation strategies.

Applying a weight of evidence approach to the evaluation of developmental toxicity of biopharmaceuticals

Toxicity studies in pregnant animals are not always necessary for assessing the human risk of developmental toxicity of biopharmaceuticals. The growing experience and information on target biology and molecule-specific pharmacokinetics present a powerful approach to accurately anticipate effects of target engagement by biopharmaceuticals using a weight of evidence approach. The weight of evidence assessment should include all available data including target biology, pharmacokinetics, class effects, genetically modified animals, human mutations, and a thorough literature review. When assimilated, this weight of evidence evaluation may be sufficient to inform risk for specific clinical indications and patient populations. While under current guidance this approach is only applicable for drugs and biologics for oncology, the authors would like to suggest that this approach may also be appropriate for other disease indications. When there is an unacceptable level of uncertainty and a toxicity study in pregnant animals could impact human risk assessment, then such studies should be considered. Determination of appropriate nonclinical species for developmental toxicity studies to inform human risk should consider species-specific limitations, reproductive physiology, and pharmacology of the biopharmaceutical. This paper will provide considerations and examples of the weight of evidence approach to evaluating the human risk of developmental toxicity of biopharmaceuticals.

Natalizumab during pregnancy and lactation

BACKGROUND

Managing medication during pregnancy and lactation in multiple sclerosis (MS) patients needs to balance potential risks to the newborn with the substantial risks of ongoing disease activity.

OBJECTIVE

To evaluate the potential transfer of natalizumab (NAT) into breast milk and into the serum of newborn babies in women who continued NAT treatment during pregnancy and lactation.

METHODS

Serum samples of 11 mother-infant pairs and mother milk samples of a further 4 women were analyzed for free NAT using a HL60 cell-based fluorescence-activated cell sorting (FACS) assay. Two mother-baby pairs were analyzed for cell-bound NAT, very-late-antigen (VLA)-4 expression, and saturation with NAT on immune cells by FACS analysis.

RESULTS

In the majority of the mother-infant serum pairs (6/11) and in all breast milk samples, free NAT was detectable. Cell-bound NAT was measurable in both mother-baby pairs with significant higher levels in babies. VLA-4 expression seems to be higher in newborns. Saturation with NAT was comparable between newborns and mothers.

CONCLUSION

NAT can pass placental barrier before delivery and into breast milk. Measurable NAT on neonatal lymphocytes may have functional impact. Further investigations are needed to clarify safety and risk of NAT exposure during pregnancy and lactation.

Evaluation of pregnancy outcomes from the Tysabri® (natalizumab) pregnancy exposure registry: a global, observational, follow-up study

Background

Patients with multiple sclerosis (MS) or Crohn’s disease (CD) being treated with natalizumab (Tysabri®, Biogen) who are planning to become pregnant or discover they are pregnant after exposure to natalizumab are currently advised to balance the potential benefits and potential risks of exposure when considering treatment options. This study was undertaken to evaluate pregnancy outcomes of women with MS or CD who were exposed to natalizumab at any time within 3 months prior to conception or during pregnancy. A pregnancy registry was created to better understand the effect of natalizumab exposure on pregnancy outcomes.

Methods

The Tysabri Pregnancy Exposure Registry was a global, observational exposure registration and follow-up study. Evaluations included spontaneous abortions (<22 weeks gestational age), fetal losses (≥22 weeks gestational age), ectopic pregnancies, elective or therapeutic terminations, stillbirths, birth defects, and live births. Birth defects were reviewed and coded in accordance with the Metropolitan Atlanta Congenital Defects Program (MACDP) classification of birth defects.

Results

A total of 369 patients with MS and 7 patients with CD were enrolled prospectively, of whom 355 patients (99.4 %; 349 MS and 6 CD) had known pregnancy outcomes (including 8 twin sets). The spontaneous abortion rate was 9.0 % (n = 32; 95 % confidence interval [C. I.], 6.3–12.5 %). An independent advisory committee review determined the major birth defect rate to be 5.05 % (16 of 316 live births + 1 elective abortion; 95 % C. I., 2.9–8.1 %). The mean gestational age of the live-born infants was 38.3 weeks, and the mean birth weight was 3158.3 g.

Conclusions

Although the overall rate of birth defects was higher than that observed by the MACDP, these registry outcomes showed no specific pattern of malformations that would suggest a drug effect, and the spontaneous abortion rate was consistent with that of the general population.

Trial registration

ClinicalTrials.gov NCT00472992 (11 May 2007).

Fertility, pregnancy and childbirth in patients with multiple sclerosis: impact of disease-modifying drugs

In recent decades, pregnancy-related issues in multiple sclerosis (MS) have received growing interest. MS is more frequent in women than in men and typically starts during child-bearing age. An increasing number of disease-modifying drugs (DMDs) for the treatment of MS are becoming available. Gathering information on their influences on pregnancy-related issues is of crucial importance for the counselling of MS patients. As for the immunomodulatory drugs (interferons and glatiramer acetate), accumulating evidence points to the relative safety of pregnancy exposure in terms of maternal and foetal outcomes. In case of higher clinical disease activity before pregnancy, these drugs could be continued until conception. As for the 'newer' drugs (fingolimod, natalizumab, teriflunomide, dimethyl fumarate and alemtuzumab), the information is more limited. Whereas fingolimod and teriflunomide are likely associated with an increased risk of foetal malformations, the effects of natalizumab, dimethyl fumarate and alemtuzumab still need to be ascertained. This article provides a review of the available information on the use of DMDs during pregnancy, with a specific focus on fertility, foetal development, delivery and breast-feeding.

The use of biologic agents in pregnancy and breastfeeding

Biologic therapies, including anti-tumor necrosis factor antibody therapy and anti-integrin antibodies, are currently approved for the treatment of and are increasingly being used in patients with moderate to severe inflammatory bowel disease, including Crohn disease and ulcerative colitis. Because patients who require these medications are often in their child-bearing years, knowledge of the safety of these medications before and after pregnancy is imperative. This article summarizes the available data regarding the use of biologic therapy during and after pregnancy, highlighting such issues as safety for mother and newborn, length of medication use during pregnancy, and breastfeeding after pregnancy while on biologic therapy.

Pregnancy and fetal outcomes following natalizumab exposure in pregnancy. A prospective, controlled observational study

BACKGROUND

Safety data on first-trimester natalizumab exposure are scarce, as natalizumab is usually withdrawn three months before pregnancy.

OBJECTIVE

The objective of this paper is to investigate the fetal safety of exposure to natalizumab (Tysabri(®)) during the first trimester of pregnancy using disease-matched (DM) and healthy control (HC) comparison groups.

METHODS

A total of 101 German women with RRMS exposed to natalizumab during the first trimester of pregnancy were identified. Birth outcomes in the exposed group were compared to a DM group (N = 78) with or without exposure to other disease-modifying drugs, and an HC group (N = 97).

RESULTS

A total of 77, 69 and 92 live births occurred in the Exposed, DM and HC groups, respectively. The rates of major malformations (p = 0.67), low birth weight (<2500 grams) (p = 1.0) and premature birth (p = 0.37) did not differ among groups. Higher miscarriage rates (p = 0.002) and lower birth weights (p = 0.001) occurred among the Exposed and DM groups, as compared to the HC; however, there was no significant difference between the Exposed and DM groups.

CONCLUSION

Exposure to natalizumab in early pregnancy does not appear to increase the risk of adverse pregnancy outcomes in comparison to a DM group not exposed to natalizumab.

Species differences in developmental toxicity of epoxiconazole and its relevance to humans

Epoxiconazole, a triazole-based fungicide, was tested in toxicokinetic, prenatal and pre-postnatal toxicity studies in guinea pigs, following oral (gavage) administration at several dose levels (high dose: 90 mg/kg body weight per day). Maternal toxicity was evidenced by slightly increased abortion rates and by histopathological changes in adrenal glands, suggesting maternal stress. No compound-related increase in the incidence of malformations or variations was observed in the prenatal study. In the pre-postnatal study, epoxiconazole did not adversely affect gestation length, parturition, or postnatal growth and development. Administration of epoxiconazole did not alter circulating estradiol levels. Histopathological examination of the placentas did not reveal compound-related effects. The results in guinea pigs are strikingly different to those observed in pregnant rats, in which maternal estrogen depletion, pathological alteration of placentas, increased gestation length, late fetal death, and dystocia were observed after administration of epoxiconazole. In the studies reported here, analysis of maternal plasma concentrations and metabolism after administration of radiolabeled epoxiconazole demonstrated that the different results in rats and guinea pigs were not due to different exposures of the animals. A comprehensive comparison of hormonal regulation of pregnancy and birth in murid rodents and primates indicates that the effects on pregnancy and parturition observed in rats are not applicable to humans. In contrast, the pregnant guinea pig shares many similarities to pregnant humans regarding hormonal regulation and is therefore considered to be a suitable species for extrapolation of related effects to humans.

Multiple sclerosis and pregnancy: maternal considerations

Multiple sclerosis (MS) is the most commonly acquired neurological disorder affecting young adults of reproductive age with approximately a 3:1 female-to-male ratio. Pregnancy is not contraindicated in MS but remains to be an issue that raises many questions. Although relapse rates tend to increase in the first 3 months postpartum, pregnancy does not seem to be a detriment to the long-term progression of MS and has a protective effect on reducing relapses, especially during the third trimester. MS does not appear to affect fertility or increase the risk of congenital anomalies or pregnancy complications. There has been some evidence that maternal treatment with β interferons, the most commonly used disease-modifying therapies in MS, may cause adverse reproductive outcomes, prompting the US FDA to issue warnings about their use at conception and during pregnancy.

Multiple sclerosis and pregnancy: therapeutic considerations

For women with multiple sclerosis (MS) who become pregnant, the risks and benefits of ongoing therapy for the health of both the mother and the fetus must be carefully considered. Based on a literature review and our MS center's standard practices, we provide guidance to aid clinical decision making in the absence of clear evidence-based clinical practice guidelines. Women seeking to achieve pregnancy should generally discontinue disease-modifying therapy use prior to attempting conception. For example, the immunosuppressant mitoxantrone is teratogenic and should be prescribed only with the assurance of effective contraception. Conception should be discouraged for patients on fingolimod, because of the limited information available on human pregnancy outcomes. Current evidence, including data from pregnancy registries for glatiramer acetate (GA), interferon beta-1a (IFNβ-1a), and natalizumab, has not shown specific patterns of malformations suggesting teratogenicity. Pregnancy registry data have not been published for IFNβ-1b. During breastfeeding, intravenous immunoglobulin and corticosteroids are generally safe and may be associated with a reduction in postpartum relapses; however, a washout period is recommended between corticosteroid administration and the resumption of breastfeeding. Clinical data on the use of IFNβ, GA, and natalizumab during lactation are limited. Mitoxantrone is contraindicated during breastfeeding, and fingolimod should be avoided in nursing mothers, because of a lack of data.

Concordance of preclinical and clinical pharmacology and toxicology of therapeutic monoclonal antibodies and fusion proteins: cell surface targets

Monoclonal antibodies (mAbs) and fusion proteins directed towards cell surface targets make an important contribution to the treatment of disease. The purpose of this review was to correlate the clinical and preclinical data on the 15 currently approved mAbs and fusion proteins targeted to the cell surface. The principal sources used to gather data were: the peer reviewed Literature; European Medicines Agency 'Scientific Discussions'; and the US Food and Drug Administration 'Pharmacology/Toxicology Reviews' and package inserts (United States Prescribing Information). Data on the 15 approved biopharmaceuticals were included: abatacept; abciximab; alefacept; alemtuzumab; basiliximab; cetuximab; daclizumab; efalizumab; ipilimumab; muromonab; natalizumab; panitumumab; rituximab; tocilizumab; and trastuzumab. For statistical analysis of concordance, data from these 15 were combined with data on the approved mAbs and fusion proteins directed towards soluble targets. Good concordance with human pharmacodynamics was found for mice receiving surrogates or non-human primates (NHPs) receiving the human pharmaceutical. In contrast, there was poor concordance for human pharmacodynamics in genetically deficient mice and for human adverse effects in all three test systems. No evidence that NHPs have superior predictive value was found.

Accidental natalizumab administration to the third trimester of pregnancy in an adolescent patient with multiple sclerosis

BACKGROUND

Natalizumab is neither licensed for the use in adolescents nor during pregnancy. There are no reports of accidental natalizumab exposure during pregnancy continued as long as to the third trimester of pregnancy.

AIMS

We report the outcome of pregnancy in a 17-year-old adolescent patient with multiple sclerosis (MS) treated with natalizumab from the age of 16, who was diagnosed to be pregnant in the 31st gestational week (gw) of pregnancy. To our knowledge, this report describes the first patient receiving natalizumab to the third trimester of pregnancy.

CASE REPORT

  Because of high relapse activity, natalizumab treatment was administered in an adolescent patient with MS. Pregnancy was diagnosed in the 31st gw after 17 natalizumab infusions, seven of them accidentally during pregnancy.

RESULTS

Pre- and postnatal development of the child was normal.

CONCLUSIONS

The case reported indicates that accidentally continued natalizumab treatment until few weeks before delivery may have no negative impact on the developing foetus.

Pregnancy and natalizumab: results of an observational study in 35 accidental pregnancies during natalizumab treatment

BACKGROUND

Natalizumab, a therapeutic monoclonal antibody approved for the treatment of relapsing-remitting multiple sclerosis (RRMS), is recommended to be withdrawn 3 months prior to a planned pregnancy. Our aim was to analyse the safety and impact of natalizumab exposure on course of disease and pregnancy outcome.

OBJECTIVES

Prospective follow-up of women with MS who became accidentally pregnant during natalizumab treatment in comparison with pregnancies of women with MS not exposed to disease-modifying treatments (DMT).

METHOD

35 women with MS who became accidentally pregnant while treated with natalizumab, and 23 women with MS who became pregnant devoid of any DMT as a control group, were chosen.

RESULTS

All pregnancies except one were followed in a prospective fashion. Of the women exposed to natalizumab during pregnancy, 29 women gave birth to 28 healthy children; one child was born with hexadactyly. Five pregnancies ended in an early miscarriage and one woman decided to undergo an elective termination of pregnancy. MS activity did not rebound during pregnancy or post partum after natalizumab was withdrawn, and no significant differences were observed when compared with the non-DMT-exposed control group.

CONCLUSION

Our data may support the notion that an elective termination of pregnancy due to natalizumab exposure may not be necessary, but rather requires careful monitoring. Women should still be advised to stop natalizumab in the course of planned pregnancy until more data on long-term outcomes are available.