Impact of intensive stem cell mobilization therapy on outcomes following autologous stem cell transplantation (ASCT) for non- Hodgkin lymphoma (NHL)

Abstract

8119 Background: We retrospectively evaluated the impact of intense [I] stem cell mobilization therapy on event-free survival [EFS] and overall survival [OS] following ASCT for NHL. Methods: 80 patients (pt) were studied (2 Burkitt, 3 primary CNS, 3 follicular, 2 intravascular, 43 large cell, 12 mantle cell, 9 transformed, and 6 peripheral T-cell). Patients with very-high risk features (LDH > 500 IU/L, first remissions < 1 year, 2 or more extra-nodal sites, and/or primary CNS/intravascular/mantle cell/peripheral T-cell histology) were prospectively allocated to I stem cell mobilization (requiring hospitalization) with either cyclophosphamide [C] (6 g/m2) + etoposide [E] (2g/m2) + filgrastim [G-CSF] (±rituximab [R]) (n=5) or with cytarabine [A] (2 g/m2 bid for 8 doses) + E (40 mg/kg) + G- CSF (±R) (n=45). 30 pt were mobilized (outpatient) with C 4g/m2 + G-CSF ±R (non-intense [NI] mobilization). 76 pt received ASCT conditioning with carmustine [B] + E and C (CBV) and 2 with B + E + A and melphalan (BEAM); 2 pt did not undergo ASCT. Results: The median age was 54 (21–69 years [yr]) and 57% had an elevated LDH at presentation. 39 pt (49%) were primary induction failures (PIF). At NHL presentation, 38% were IPI high-intermediate or high risk. There were 3 non-relapse mortalities (4%): (2) B pneumonitis and (1) multi-organ failure (all following ASCT). With a median follow-up of 1.8 yr (0.1–6.4), the overall median EFS is 3 yr (48% [34–62] at 4 yr) and the median OS is 4.7 yr (59% [43–72] at 4 yr). Patients receiving I mobilization were similar to those receiving NI mobilization in terms of the # of prior therapies (median 2, each), the presenting IPI risk score, and the percent PIF (57% vs 41%; p=0.17). There were trends favoring I mobilization for both 4 yr EFS (58% [41–75] vs 35% [13–57]) and OS (66% [48–84] vs 52% [32–72]), neither statistically significant. In the sub-group of large B-cell NHL, 4 yr EFS was the same in pt receiving I mobilization (81% [63–98] vs 73% [50–96]; p=0.33) but OS was better (91% [79–100] vs 58% [35–82]; p=0.02). Conclusions: I stem cell mobilization therapy, compared to NI mobilization therapy, may improve outcomes for NHL pt with very-high risk features and may overcome the anticipated poor prognosis of these pt. No significant financial relationships to disclose.