Abstract
Abstract
Background
Inotuzumab (InO)‐based frontline regimens have significantly improved the survival of older patients with Philadelphia‐negative (Ph–) B‐cell acute lymphoblastic leukemia (B‐ALL). Yet, outcome after relapse is not reported for this population.
Methods
The retrospective RELAPSINO study describes post‐relapse outcome of 48 older patients treated front‐line with a combination of InO and low‐dose chemotherapy in the EWALL‐INO trial (NCT03249870). At relapse (91% medullary), median age was 70 years and median duration of first complete remission (CR1) 15.2 months. CD19 or CD22 expression loss was observed in respectively 13% and 23% of evaluable cases. Most patients (85%) received salvage therapy (blinatumomab, low dose or intensive chemotherapy, in combination or not). There was no InO re‐treatment.
Results
Overall, CR2 was reached by 51% of the patients. Median event‐free survivals (EFS, 3.2 months) and overall survivals (OS, 4.5 months) were dismal. For patients achieving CR2, 2‐year OS was 46% and leukemia‐free survival (LFS) was 36%. By multivariable analysis, not receiving intensive chemotherapy was associated with significantly lower EFS (hazard ratio [HR], 3.28; 95% confidence interval [CI], 1.43–7.53,
p
= .005), LFS (HR, 13.2; 95% CI, 2.46–70.88,
p
= .003), and OS (HR, 3.25; 95% CI, 1.39–7.59,
p
= .006). CR1 duration ≥12 months was significantly associated with better EFS (HR, 0.31; 95% CI, 0.14–0.67,
p
= .003), LFS (HR, 0.16; 95% CI, 0.04–0.72,
p
= .01), and OS (HR, 0.42; 95% CI, 0.20–0.89,
p
= .023). Not achieving CR2 was associated with lower OS (HR, 8.0; 95% CI, 3.25–20.1,
p
Conclusions
These results indicate that salvage regimen should be proposed in this context, allowing 50% of patients to achieve CR2 and have better survival.