Interaction Review

Dr. Sharma, thank you for taking my call. I wanted to follow up on the Neurexil clinical data we discussed at the neurology symposium last month.

Yes, Sarah. I've actually been thinking about it. I have about twenty patients on dimethyl fumarate who are experiencing GI tolerability issues. I'm considering switches.

That's a common challenge I hear from neurologists. In the NEXUS switching study, patients who transitioned from dimethyl fumarate to Neurexil showed significant improvement in GI tolerability, with only 4% reporting any GI adverse events compared to 38% on their prior therapy.

What about efficacy? I don't want to sacrifice disease control for better tolerability.

Great concern. The annualized relapse rate in the NEXUS trial was 0.13 for Neurexil versus 0.22 for dimethyl fumarate at 96 weeks. On MRI outcomes, 78% of Neurexil patients showed no new T2 lesions compared to 62% with dimethyl fumarate. Of course, these are cross-trial comparisons and should be interpreted with appropriate caution.

I appreciate the caveat on cross-trial comparisons. What about the lymphocyte monitoring requirements? I've heard some oral MS therapies require more frequent lab work.

Neurexil does require a CBC with differential before initiation and then every six months during treatment. If the lymphocyte count drops below 0.5 times ten to the ninth per liter, treatment should be interrupted per the prescribing information. In the clinical trials, lymphopenia requiring interruption occurred in approximately 5% of patients.

That's manageable. What's the formulary status at most of the major payers in our region?

Neurexil has preferred formulary status with BlueCross, Aetna, and UnitedHealthcare in this region. For Cigna, it's covered but requires step therapy through an injectable first. We have a dedicated access team that can help navigate any prior authorization challenges.

My biggest concern with switching is the washout period. Is there one with Neurexil?

For patients coming from dimethyl fumarate, no formal washout is required as long as the CBC is within acceptable range. The recommended approach is to start Neurexil the day after the last dose of dimethyl fumarate, which minimizes any gap in disease coverage.

That makes things much simpler. I think I'll start with three or four of my most symptomatic GI patients first.

That sounds like a great approach. I can also connect those patients with our Neurexil Patient Support Program, which includes dedicated case managers, copay assistance, and a nurse educator for the first 90 days to help with any questions during the transition.

Perfect. Send me the enrollment forms and the switching protocol, and let's plan to check in after a month.