Do Disease modifying therapies for multiple sclerosis impact male fertility?

Here is My Question:
My husband has been on Gilenya for about 5 years. He will now go on Kesimpta. We will be trying for a baby soon. Does Kesimpta affect male sperm/fertility? I understand there is not much research but I need some sort of reassurance. Thank you.

Answer:
We have no data on the effects of Kesimpta on male fertility. We do have data showing that another drug (Ocrelizumab) with the same mechanism of action--targeting and depletion of anti-CD20 positive B cells--does not affect gonadal hormone levels or sperm function after 12 months of therapy. 

It is more likely that medications used to treat MS related symptoms (anti-depressants and anti-spasticity medications) may negatively affect both sexual function and male fertility and men should continue the risks and benefits of continuing these drug therapies during pregnancy.

Among the disease modifying therapies Ocrelizumab (Ocrevus), Rituximab, Ofatumumab (Kesimpta), Natalizumab (Tysabri), Dimethyfumarate, S1P modulators (Fingolimod, zeposia and Mayzent) , interferons and glatiramer acetate have no specific warnings for men trying to conceive.  There are very specific warnings and precautions for men on Teriflunomide (aubagio), Cladribine (Mavenclad), Mitoxantrone (lemtrada), azathioprine, methotrexate and cyclophosphamide trying to conceive. These drugs must be stopped for specific periods of time or sometimes avoided until the man donates to a sperm bank if he wishes to conceive in the future.

I hope this helps. In general, most neurologists and patients do not consider these issues in their male patients except as mentioned in the last paragraph, primarily because there is so little data available to raise any concerns. You can be thankful that there is at least some data available to guide you on the anti-CD20 class of medications and this data seems reassuring. 

Revere P (Rip) Kinkel, MDProfessor of Neurosciences
Director of the Multiple Sclerosis Program
University of California San Diego
#multiplesclerosis #MS