Impact of Tremfya (Guselkumab) on Fertility
For patients concerned about fertility, Tremfya (guselkumab) should be considered with caution in men trying to conceive due to limited data, while women should avoid the medication during pregnancy planning and pregnancy itself.
Male Fertility
Current Evidence and Recommendations
- According to the 2025 EULAR recommendations, there is limited or no data available on the impact of guselkumab on male fertility 1.
- The EULAR guidelines specifically recommend considering switching to an alternative antirheumatic medication in male patients trying to conceive due to insufficient safety data rather than evidence of harm 1.
- The FDA label for Tremfya notes that animal studies showed no effects on fertility parameters in male guinea pigs when administered guselkumab at doses 6-10 times the human exposure 2.
Clinical Approach for Men
- For men requiring psoriasis treatment while planning conception:
- Consider switching to TNF inhibitor biologics which have more safety data on male fertility and offspring outcomes 1.
- If continuing guselkumab is necessary due to disease control:
- Discuss the limited available data with the patient
- Monitor disease activity closely, as high disease activity itself may impair male fertility 1
Female Fertility and Pregnancy
Current Evidence and Recommendations
- No human pregnancy studies are available specifically for guselkumab 1.
- Animal studies with guselkumab have not shown harm to the developing fetus, but this cannot be directly extrapolated to humans 1.
- The British Association of Dermatologists guidelines recommend that pregnancy should be avoided in patients receiving biologic therapy, and effective contraception is strongly recommended 1.
Clinical Approach for Women
For women planning pregnancy:
- Discontinue guselkumab before attempting conception
- Consider switching to pregnancy-compatible alternatives if treatment is needed
- Hydroxychloroquine, sulfasalazine, azathioprine, cyclosporine, tacrolimus, and certain TNF inhibitors are considered safer options during pregnancy planning 3
If pregnancy occurs during guselkumab treatment:
- Refer to a specialist fetal medicine unit for assessment
- Consider discontinuing therapy 1
- Monitor closely for potential complications
General Considerations for All Patients
Disease Activity Management
- Controlling disease activity is important for fertility in both men and women, as high disease activity itself may impair fertility 1.
- Balance the risks of untreated disease against the potential risks of medication.
Alternative Treatments
- For patients planning conception, consider switching to medications with more established safety profiles:
- TNF inhibitor biologics have more extensive safety data in reproduction 1
- Non-biologic options may be appropriate depending on disease severity
Monitoring and Follow-up
- Regular assessment of disease activity
- For men continuing guselkumab while attempting conception with partner, monitor for treatment efficacy and any emerging safety data
- For women, ensure effective contraception while on guselkumab
Common Pitfalls to Avoid
- Assuming all biologics have similar fertility profiles - Different biologics have varying levels of evidence regarding reproductive safety
- Overlooking disease activity - Uncontrolled disease may itself impact fertility
- Failing to plan ahead - Discuss fertility implications before initiating treatment in patients of reproductive age
The decision to use guselkumab in patients concerned about fertility should carefully weigh disease control benefits against the limited available safety data, with consideration of alternative treatments that have more established reproductive safety profiles.