Olumiant ® (baricitinib)

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Does Olumiant® (baricitinib) affect male fertility?

In animal studies, baricitinib did not have an effect on male reproductive organs or sperm endpoints. However, there is a potential to decrease male fertility.


Baricitinib Label Information 

Studies in animals suggest that treatment with baricitinib has the potential to decrease female fertility while on treatment, but there was no effect on male spermatogenesis.1

In a combined male/female rat fertility study, baricitinib decreased overall mating performance (decreased fertility and conception indices).1

  • In female rats there were decreased numbers of corpora lutea and implantation sites, increased pre-implantation loss, and/or adverse effects on intrauterine survival of the embryos.1
  • Since there were no effects on spermatogenesis (as assessed by histopathology) or semen/sperm endpoints in male rats, the decreased overall mating performance was likely the result of these female effects.1

Combined Male and Female Animal Fertility Study

Male rats were dosed with 0, 5, 15, or 50 mg/kg of BARI daily for 6 weeks including 4 weeks prior to cohabitation with female rats treated with 0, 5, 25, or 100 mg/kg.2

The no-observed-adverse-effect level (NOAEL) for male fertility was 15 mg/kg based on rat studies.2

Effects on Reproductive Organs and Sperm in Animals

Histologic studies found no change in male reproductive organs, and no effects on sperm motility, concentration, and morphology at any BARI dose level.2

Effects on Fertility and Early Embryonic Development

Results by Doses

At doses of 50 and 100 mg/kg/day (approximately 113 and 169 times a BARI dose of 2 mg in male and female rats, respectively), reproductive performance was unaffected in both genders.2

At doses of 15 mg/kg and 25 mg/kg (approximately 25 and 48 times a BARI dose of 2 mg), fertility was unaffected in male and female rats.2

Potential Cause of Decreased Fertility

Based on the study design, it could not be determined if fertility results were attributable to toxicities in one sex or both. However, since there were no effects on spermatogenesis or semen/sperm endpoints in male rats, the decreased overall mating performance was likely the result of fertility effects in female rats including

  • decreased corpora lutea and implantation sites
  • increased preimplantation loss, and
  • adverse effects (AE) on intrauterine survival.2

The NOAEL was 5 mg/kg for female fertility and early embryonic development based on rat studies.2

Treatment-Emergent Adverse Events in Clinical Trials

A treatment-emergent adverse event (TEAE) is an AE that either occurred or worsened in severity after the first dose of study treatment and did not necessarily have a causal relationship to study treatment.2

Rheumatoid Arthritis

The All-BARI-Rheumatoid Arthritis (RA) analysis set included 3770 patients with RA who received BARI at a variety of doses from 1 phase 1, 3 phase 2, and 5 phase 3 studies (RA-BEGIN, RA-BEAM, RA-BUILD, RA-BEACON, and RA-BALANCE). Data include a long-term extension study (RA-BEYOND) with

  • 14,744 patient-years of exposure (PYE) to BARI
  • 15,114 patient years (PY) overall observation including time on BARI and follow up
  • median exposure of 4.6 years, and
  • maximum exposure of 9.3 years.3

In this safety analysis, sperm-related AEs such as spermatogenesis abnormal (Medical Dictionary for Regulatory Activities [MedDRA] preferred term) have not been reported.2

Sperm analysis was not routinely conducted throughout the studies, and male participants were required to use birth control throughout the duration of the study as described above.2

Atopic Dermatitis

The All-BARI-Atopic Dermatitis (AD) analysis set includes 2531 patients (PYE=2247.4) with AD who received at least 1 dose of BARI at different strengths from 1 phase 2, 5 phase 3 (BREEZE-AD1, BREEZE-AD2, BREEZE-AD4, BREEZE-AD5, and BREEZE-AD7), and 2 phase 3 extension studies (BREEZE-AD3 and BREEZE-AD6).4

In this safety analysis, sperm-related AEs such as spermatogenesis abnormal (MedDRA preferred term) have not been reported.2

Alopecia Areata

The All-BARI-Alopecia Areata (AA) dataset includes 1244 patients with AA who received BARI at a variety of doses from the phase 2/3 BRAVE-AA1 and phase 3 BRAVE-AA2 studies. Data include

  • 1362.2 PYE to BARI
  • a mean exposure of 400 days, and
  • a maximum exposure of 903 days.5

In this safety analysis, sperm-related AEs such as spermatogenesis abnormal (MedDRA preferred term) have not been reported.2

Postmarketing Spontaneous Reports

The following information is valid for data received up through December 13, 2021. The data do not represent the number of AEs in a treated population. They merely represent the number of a particular AE reported to the company. The following MedDRA preferred terms have not been reported to the Eli Lilly and Company spontaneous AE database

  • spermatogenesis abnormal, and
  • paternal exposure during pregnancy.2

Spontaneous reporting of AEs can be highly variable and is not controlled clinical information on which to assess causality of a drug to an AE. Spontaneous reporting has limitations due to bias in reporting including incomplete information concerning the patient. When verification of product manufactured by Lilly is not obtainable, these cases are included in the spontaneous database.

Use in Individuals of Reproductive Potential

Based on the mechanism of action and findings in animals, BARI may cause fetal harm.2

If the patient becomes pregnant while taking BARI, inform the patient of the potential for hazard to the fetus. BARI should only be continued during pregnancy if the potential benefit justifies the potential risk to the fetus.2

Women of reproductive potential should take appropriate precautions to avoid becoming pregnant during treatment with BARI and for at least 1 week after the final BARI treatment.2

Clinical Trial Data Related to Male Patients and Procreation

In all BARI clinical trials, male patients agreed to use 2 forms of birth control (1 must be highly effective) while engaging in sexual intercourse with female partners of childbearing potential

  • while enrolled in the study, and
  • for at least 28 days following the last dose of study treatment.2

Washout Period Prior to Conception

Eli Lilly cannot provide recommendations on whether male patients should continue or interrupt BARI treatment before conception as this has not been studied.2


1Olumiant [summary of product characteristics]. Eli Lilly Nederland B.V., The Netherlands.

2Data on file, Eli Lilly and Company and/or one of its subsidiaries.

3Taylor PC, Takeuchi T, Burmester GR, et al. Safety of baricitinib for the treatment of rheumatoid arthritis over a median of 4.6 and up to 9.3 years of treatment: final results from long-term extension study and integrated database. Ann Rheum Dis. 2022;81(3):335-343. https://doi.org/10.1136/annrheumdis-2021-221276

4Bieber T, Thyssen JP, Reich K, et al. Pooled safety analysis of baricitinib in adult patients with atopic dermatitis from 8 randomized clinical trials. J Eur Acad Dermatol Venereol. 2021;35(2):476-485. https://doi.org/10.1111/jdv.16948

5King B, Mostaghimi A, Shimomura Y, et al. Integrated safety analysis of baricitinib in adults with severe alopecia areata from two randomized clinical trials. Poster presented at: Annual Meeting of the American Academy of Dermatology Association (AAD); March 25-29, 2022; Boston, MA. Accessed April 29, 2022. https://aad-eposters.s3.amazonaws.com/AM2022/poster/33966/Integrated+safety+analysis+of+baricitinib+in+adults+with+severe+alopecia+areata+from+two+randomized+clinical+trials.pdf

Date of Last Review: 13 April 2022

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