Early molecular response of marrow disease to biologic therapy is highly prognostic in XXXX .

@entity1 @entity41 @entity2841 @entity521
PURPOSE: A promising treatment strategy for stage 4 @entity521 @entity1 is the repeated application of anti-GD2 immunotherapy after activating myeloid effectors with @entity2841 ( @entity2841 ). To use early marrow response as a prognostic marker is particularly relevant for @entity1 not likely to benefit from this therapy. @entity1 AND METHODS: Eighty-six stage 4 @entity521 @entity1 older than 1 year at diagnosis were classified in four clinical groups on protocol entry: complete remission or very good partial remission (n = 33), primary refractory (n = 33), secondary refractory (n = 10), and progressive disease (n = 10). Bone marrow samples collected before and following treatment were assayed for GD2 synthase mRNA by real-time reverse transcriptase polymerase chain reaction. Response and survival analyses were performed on posttreatment samples before the third cycle at 1.8 months from protocol entry. RESULTS: GD2 synthase mRNA was evident in pretreatment marrow samples of the four clinical groups (42%, 52%, 60%, and 80% of samples, respectively), with median transcript level of 10.0, 16.6, 26.5, and 87.2, respectively. This marker became negative following antibody plus @entity2841 in 77% of complete remission or very good partial remission, 45% of primary refractory, 25% of secondary refractory, and 0% of progressive disease group. Progression-free survival was statistically different between responder and nonresponder groups (P <.0001). Among @entity1 with @entity41 , molecular responders had a significantly lower risk of disease progression at a median follow-up of 29.8 months (P =.0001). CONCLUSION: GD2 synthase mRNA is a sensitive response marker of @entity521 in the bone marrow. It is particularly useful for @entity41 evaluation and may potentially be useful as an early predictor of resistance to antibody plus @entity2841 immunotherapy.
