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Deepening of response after completing rituximab‐containing therapy in patients with Waldenstrom macroglobulinemia
Author(s) -
Castillo Jorge J.,
Gustine Joshua N.,
Keezer Andrew,
Meid Kirsten,
Flynn Catherine A.,
Dubeau Toni E.,
Chan Gloria,
Chen Jiaji,
Demos Maria G.,
Guerrera Maria L.,
Jimenez Cristina,
Kofides Amanda,
Liu Xia,
Munshi Manit,
Tsakmaklis Nicholas,
Patterson Christopher J.,
Xu Lian,
Yang Guang,
Hunter Zachary R.,
Treon Steven P.
Publication year - 2020
Publication title -
american journal of hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.456
H-Index - 105
eISSN - 1096-8652
pISSN - 0361-8609
DOI - 10.1002/ajh.25712
Subject(s) - rituximab , medicine , waldenstrom macroglobulinemia , macroglobulinemia , maintenance therapy , gastroenterology , retrospective cohort study , induction therapy , surgery , immunology , chemotherapy , lymphoma , multiple myeloma
Rituximab‐containing regimens are commonly used for frontline therapy in patients with symptomatic Waldenström macroglobulinemia (WM). We had observed that a portion of WM patients experienced deepening of response months to years after therapy completion. We carried a retrospective study aimed at describing this phenomenon. We gathered baseline data, and responses at end of induction, end of maintenance and best response. Deepening of response was defined as ≥25% decrease in serum IgM achieved at a later time from therapy completion. Of 178 patients included, 116 (65%) received maintenance therapy and 62 (35%) were observed. In patients who received maintenance, 44 (38%) had ≥25% decrease in serum IgM level after the end of maintenance with a median time from end of maintenance to lowest IgM level of 1.6 years (range 0.1‐7.9 years). In patients who were observed, 19 (31%) had ≥25% decrease in serum IgM level after the end of induction with a median time from end of induction to lowest IgM level of 1.6 years (range 0.2‐5.1 years). Baseline hemoglobin <11.5 g/dL, bone marrow involvement ≥50%, CXCR4 mutations and serum IgM ≥4000 mg/dL were associated with lower odds of deepening of response after therapy completion. Deepening of response was associated with better progression‐free survival (PFS; HR 0.46, 95% CI 0.26‐0.80; P = .006) and better survival after frontline treatment initiation (SAFTI; HR 0.21, 95% CI 0.06‐0.73; P = .01). In conclusion, deepening of response occurs in one third of WM patients after completing rituximab‐containing regimens and was associated with better PFS and SAFTI.