Outcomes of Adult Patients with Relapsed/Refractory Burkitt or Burkitt-like Leukemia/Lymphoma

Background: Burkitt leukemia/lymphoma is a highly aggressive B-cell neoplasm that is potentially curable with chemoimmunotherapy. While patients (pts) who are refractory to initial therapy or subsequently relapse are considered to have a poor prognosis, few studies have systematically evaluated the outcomes of these pts. Methods: We retrospectively identified 146 adult pts with Burkitt or Burkitt-like leukemia or lymphoma treated at our institution between 1992 and 2013 with frontline hyper-CVAD-based regimens. 12 pts died before initial response assessment and 4 were unevaluable due to inadequate records; these pts were therefore excluded from the analysis. Among the 130 pts evaluable for response, 36 pts (28%) had relapsed (n=33) or refractory (n=3) Burkitt or Burkitt-like leukemia/lymphoma and are the subject of this analysis. Early and late relapse were defined as relapse Results: The median age of the evaluable population was 51 years (range, 18-76 years). Among the 36 relapsed/refractory pts, initial presentation was leukemia in 29 pts and lymphoma in 7 pts. Initial treatment was hyper-CVAD alone in 11 pts, hyper-CVAD plus rituximab (R-hyper-CVAD) in 24 pts, and hyper-CVAD plus ofatumumab in 1 pt. Among the 33 relapsed pts, 30 had achieved CR to frontline treatment and 3 had only achieved PR. The median time to first relapse was 6.6 months (range 0.7-75.3 months). Twelve pts (36%) and 21 pts (64%) experienced early and late relapse, respectively. Thirty relapsed/refractory pts received at least one salvage regimen, 29 of whom were evaluable for response. The backbone salvage regimens received were hyper-CVAD in 13 pts (43%), ICE in 6 (14%), EPOCH in 2 (7%), MOAD in 2 (7%), and miscellaneous regimens in 7 (23%). Subsequent stem cell transplant (SCT) was performed in 6 pts (allogeneic, n=3; autologous, n=3). The ORR to salvage chemotherapy was 38% (CR, n=8; PR, n=3); 18 pts were refractory. Among the 18 pts with late relapse who received salvage therapy, the ORR was 61%. In contrast, of the 11 pts who were refractory to frontline therapy or had early relapse, none responded to salvage therapy (P The median OS for the entire cohort (measured from time of relapse or treatment failure) was 2.7 months, with a 1-year OS rate of 10% (Figure 1A). Among responding pts, the median RFS was 3.3 months, with a 1-year RFS rate of 18% (Figure 1B). Only 2 pts were still alive without relapse at last follow-up, one who had undergone salvage autologous SCT and one who had a late relapse 75 months after initial diagnosis and was treated with R-EPOCH without SCT consolidation. Pts who responded to salvage treatment had superior OS compared to those who did not (median OS: 7.5 months vs. 1.5 months, respectively; P Conclusions: Pts with relapsed/refractory Burkitt leukemia/lymphoma have very poor outcomes, with an ORR to salvage therapy of 38% and a median OS of only 2.7 months. Pts with a remission duration after frontline therapy of ≥6 months have superior outcomes, although the OS of this group is still poor. Novel treatment strategies are needed for pts with relapsed/refractory disease. Disclosures Jabbour:ARIAD: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Novartis: Research Funding; BMS: Consultancy. Cortes:ARIAD: Consultancy, Research Funding; BMS: Consultancy, Research Funding; Novartis: Consultancy, Research Funding; Pfizer: Consultancy, Research Funding; Teva: Research Funding. Wierda:Abbvie: Research Funding; Acerta: Research Funding; Novartis: Research Funding; Gilead: Research Funding; Genentech: Research Funding. Thompson:Pharmacyclics: Consultancy, Honoraria.