Blinatumomab bests chemo in rel/ref B-ALL

Survival

At a median follow-up of 11.7 months for the blinatumomab arm and 11.8 months for the chemotherapy arm, the OS was significantly longer in the blinatumomab arm.

The median OS was 7.7 months and 4.0 months, respectively (hazard ratio for death=0.71, P=0.01).

The improvement in OS with blinatumomab was consistent across subgroups, regardless of age, prior salvage therapy, or prior allo-HSCT.

The investigators also considered the effect that post-treatment allo-HSCT might have on OS. Sixty-five patients in the blinatumomab arm and 32 in the chemotherapy arm went on to receive an allo-HSCT (24% of patients in both arms).

When the investigators censored for post-treatment allo-HSCT, the median OS was 6.9 months in the blinatumomab arm and 3.9 months in the chemotherapy arm (hazard ratio=0.66, P=0.004).

Safety

Nearly all patients in both arms (99%) experienced AEs. Grade 3 or higher AEs occurred in 87% of patients in the blinatumomab arm and 92% of those in the chemotherapy arm. Serious AEs occurred in 62% and 45%, respectively.

Grade 3 or higher AEs of interest, according to the researchers, were infection (34% with blinatumomab and 52% with chemotherapy), neutropenia (38% and 58%, respectively), elevated liver enzymes (13% and 15%, respectively), neurologic events (9% and 8%, respectively), cytokine release syndrome (5% and 0%, respectively), infusion reactions (3% and 1%, respectively), and lymphopenia (2% and 4%, respectively).

Fatal AEs occurred in 19% of patients in the blinatumomab arm and 17% of those in the chemotherapy arm.

Fatal AEs that occurred in at least 1% of patients in either arm (blinatumomab and chemotherapy, respectively) were sepsis (3% and 4%), septic shock (2% and 0%), multiorgan failure (1% and 0%), respiratory failure (<1% and 2%), and bacteremia (0% and 2%).