Phase I study of atacicept in relapsed/refractory multiple XXXX ( @entity1582 ) and Waldenstr  m's @entity8057 .

@entity1 @entity8057 @entity1582
Atacicept, a specific inhibitor of BLys and APRIL, was used in a phase I study for 14 @entity1 with @entity1582 ( @entity1582 ) and 4 with Waldenstr  m's @entity8057 (WM). They received 1 cycle of 5 once-weekly s.c. injections, followed by an extension if in stable disease or in response. The maximum tolerated dose was not identified. Of 11 @entity1 with @entity1582 who completed initial treatment, 5 @entity1 were progression-free after cycle 1 and 4 @entity1 were progression-free after extended therapy. Of 4 @entity1 with WM, 3 @entity1 were progression-free after cycle 1. Polyclonal immunoglobulin isotypes and total B cells were reduced. Plasma concentrations of soluble CD 138 decreased. Biological effect was more pronounced in WM. Of the 16 @entity1 tested at baseline, 13 had measurable levels of free APRIL (>= 25 ng/mL). In this small series, no correlations were apparent between baseline levels of free APRIL and biological or clinical response criteria.
