Do you recommend continuous antibiotic prophylaxis for patients on complement inhibitors such as eculizumab?

This is an extremely important and timely question. There simply isn’t enough data or firm guidelines on this leading to different practices. The reality is that there have been a number of meningococcal breakthrough infections in those vaccinated against meningococcal disease. Complement therapies like eculizumab and ravulizumab lead to terminal complement inhibition which is crucial for serum bactericidal activity via MAC. Even with vaccination, SBA can be prevented by complement inhibitors, thus breakthrough infections. In fact, data from the champion-NMOSD trial for ravulizumab presented at ECTRIMS in Amsterdam revealed 2 cases of breakthrough meningococcal disease. It’s important to know that close to 50% of cases are from nongroupable...

In my practice, I do NOT prescribe antibiotics routinely to patients treated with eculizumab, but, that said, I understand the approach proposed by Drs. @Dr. First Last Silversteen and @Dr. First Last, because the patient population I treat is different; I use it only in neuromuscular patients with refractory AchR antibody positive myasthenia gravis. In those patients, we often will prescribe eculizumab PRIOR to Rituximab, and I generally avoid additional immunosuppressants (other than perhaps low-dose steroids) while my patient receives eculizumab. In addition, I rarely prescribe eculizumab emergently, so I generally will ask my patient to receive the first dose of the meningococcal vaccines and wait >2 weeks before starting the eculizumab...

I agree with the perspective provided by Dr. @Dr. First Last most especially that, although infrequent, breakthrough infections with meningococcus have occurred despite vaccination with ACWY and B vaccines. My experience with Eculizumab and Ravulizumab includes patients with SLE or SLE with CAPS and clinical features of TMHA with or without identified genes associated with complement-mediated HUS. Given the concomitant immunosuppression and increased frequency of infection related to the underlying disease in contrast to, for example, PNH, concerned for even a greater risk of breakthrough infections than reported in trials leading to FDA-approved indications (e.g., PNH, aHUS, gMG, and NMOSD) of these terminal complement component inhibitors...