Drug Interaction Report

GENERALLY AVOID: Coadministration of siponimod with antineoplastic, immunosuppressive, or other immune-modulating therapies may increase the risk of unintended additive immunosuppressive effects. Siponimod causes reversible sequestration of lymphocytes in lymphoid tissues. When administered daily, siponimod produces a dose-dependent reduction in peripheral lymphocyte count to 20% to 30% of baseline values, which may increase the risk of infections. Life-threatening and rare fatal infections have occurred in association with siponimod. Decreased lymphocyte counts persist during chronic daily dosing and generally return to normal within 10 days after stopping the medication. Pharmacodynamic effects, such as decreased peripheral lymphocytes, may persist for 3 to 4 weeks after the last dose, and as a result, use of immunosuppressants during this time may also lead to additive immune effects.

MANAGEMENT: The safety and efficacy of siponimod in combination with antineoplastic, immunosuppressive, or immune-modulating agents have not been evaluated. Caution is advised during coadministration and for 3 to 4 weeks after the last dose of siponimod. Initiating treatment with siponimod after treatment with alemtuzumab is not recommended unless the benefits of siponimod treatment outweigh the risks.

The recommended maximum number of medicines in the 'immunomodulators for multiple sclerosis' category to be taken concurrently is usually one. Your list includes two medicines belonging to the 'immunomodulators for multiple sclerosis' category:

• alemtuzumab
• Mayzent (siponimod)

Note: In certain circumstances, the benefits of taking this combination of drugs may outweigh any risks. Always consult your healthcare provider before making changes to your medications or dosage.