J9321 Insurance Policy Changes

Siltuximab (Sylvant) (CPB 0884, reviewed 2026-06-03)

Aetna updated its coverage policy for siltuximab (Sylvant) effective June 3, 2026, establishing medical necessity criteria for two primary indications: Castleman's disease (multicentric and unicentric relapsed/refractory forms) and cytokine release syndrome (including CAR T-cell, lymphocyte engager, and KSHV-associated). The policy also clarifies continuation of therapy requirements and designates 20+ other cancer and inflammatory conditions as experimental/investigational. Billing teams must verify member eligibility against specific disease criteria before claim submission.