Page 77 - Haematologica Vol. 107 - September 2022

ARTICLE - High tumor burden and response to blinatumomab A. Cabannes-Hamy et al. AB
Figure 2. Outcome of MRD+ patients. A) Relapse-free survival and (B) overall survival (OS) without censoring patients at allogeneic hematopoietic stem cell transplantation time. PFS: progression-free survival; CI: confidence interval; NR: not reached.
AB
Figure 3. Outcome of relapsed patients. (A) Relapse-free survival and (B) overall survival (OS) without censoring patients at allogeneic hematopoietic stem cell transplantation time. CI: confidence interval.
We further investigated the prognostic impact of pre-bli- natumomab tumor load in the relapse cohort. In the whole cohort, regardless of the treatment line, patients who re- ceived blinatumomab in CR2+ had similar characteristics (Online Supplementary Table S2) and a better outcome as compared to patients treated in overt relapse. Indeed, 3- year RFS and OS for patients in CR2+ at the time of blina- tumomab were 59% and 66% respectively versus ≤9% (not evaluable, P=0.033) and 16% (P=0.003) respectively for pa- tients in overt relapse (Figure 3C and D). Median RFS and OS were respectively 41.6 months and not reached in CR2+ patients, versus 6.7 months and 8.9 months respect- ively in patients with overt relapse at time of blinatumo- mab initiation. A multivariate analysis considering age, high-risk cytogenetics, number of prior relapses, alloge- neic HSCT, and CR status at blinatumomab showed sig- nificantly shorter OS and RFS associated with CR status at blinatumomab and more advanced disease (Table 3).
A similar analysis performed in patients in first relapse showed the same advantage for patients exposed to bli- natumomab in second CR after chemotherapy compared to patients who received blinatumomab in overt first hematological relapse. The 3-year RFS and OS for patients in second CR were 70% (median OS not reached) and 80% (n=10) respectively versus ≤11% (not evaluable, P=0.067) and 27% (P=0.025) in first hematological relapse (Online Supplementary Figure S3).
Discussion
This retrospective, multicenter study reports the outcome of 73 adult patients treated with blinatumomab for MRD+ or relapsed BCP-ALL within the French compassionate use program. Patient outcomes, CR and MRD response rates after blinatumomab were similar to those observed in
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