Reduced-intensity chemotherapy plus inotuzumab ozogamicin, with or without blinatumomab, can be effective in older patients with newly diagnosed Ph-negative B-cell acute lymphoblastic leukemia (B-ALL), according to researchers.
The combination produced an overall response rate of 99% and a 5-year overall survival (OS) rate of 47% in a phase 2 trial.
These findings were presented at the EHA 2022 Hybrid Congress.
The study enrolled 80 patients with newly diagnosed Ph-negative B-ALL. The median age at baseline was 68 years (range, 60-87 years).
The first 49 patients received mini hyper-CVD (cyclophosphamide, dexamethasone, methotrexate, and cytarabine) for up to 8 cycles along with inotuzumab ozogamicin for the first 4 cycles. These patients could receive maintenance with POMP (6-mercaptopurine, vincristine, methotrexate, and prednisone) for up to 3 years.
The remaining 31 patients received mini hyper-CVD for up to 8 cycles, with inotuzumab ozogamicin for the first 4 cycles, followed by 4 cycles of blinatumomab. For maintenance, these patients received 3 cycles of POMP, followed by 1 cycle of blinatumomab, for a total of 12 cycles of POMP and 4 cycles of blinatumomab.
There were 6 patients who were in complete remission (CR) at enrollment and were therefore not included in the response assessment.
The overall response rate was 99%, with 66 patients achieving a CR, 6 achieving a CR with incomplete platelet recovery, and 1 achieving a CR with incomplete blood count recovery.
At day 21 of cycle 1, 80% of patients had achieved minimal residual disease (MRD) negativity by flow cytometry. Overall, 94% of patients achieved MRD negativity.
The median follow-up was 55 months. Of the 79 patients who achieved remission before or after treatment, 33 patients were still on treatment or under observation at last follow-up.
Four patients went on to hematopoietic stem cell transplant (HSCT) while in remission. Two were still alive at last follow-up, but 1 had relapsed. Two had died.
Eleven patients relapsed without undergoing HSCT, 10 of whom died. Thirty-one patients died while in remission. Six patients developed veno-occlusive disease, 1 of them after HSCT.
The 5-year remission rate was 76%, and the 5-year OS rate was 47%. OS outcomes were better for younger patients and those with low- or intermediate-risk cytogenetics.
The 5-year OS rate was 69% in patients aged 60-69 years without poor-risk cytogenetics, 39% in the same age group with poor-risk cytogenetics, 36% in patients age 70 or older without poor-risk cytogenetics, and 0% in the same age group with poor-risk cytogenetics.
The study has been amended to eliminate chemotherapy in patients age 70 and older.
Disclosures are not available for this presentation.
Haddad F, Kantarjian H, Short N, et al. Mini-hyper-CVD plus inotuzumab ozogamicin, with or without blinatumomab, in older adults with newly diagnosed B-cell acute lymphoblastic leukemia: Updates from a phase II trial. Presented at EHA 2022; June 9-12, 2022. Abstract P355.