Lead Zevalin.

Anti-CD20 conjugated to yttrium-90 (aka ibritumomab tiuxetan, aka Zevalin) improves progression-free survival (PFS) among patients with advanced follicular lymphoma in first-remission, as established in a landmark trial in 2008. No such luck in a recent phase 2 study that added Zevalin as consolidation for patients with relapsed follicular lymphoma and achieved a far worse PFS rate at one year (38%) than hypothesized (67%).