Results of the compassionate program of inotuzumab ozogamicin for adult patients with relapsed or refractory acute lymphoblastic leukemia in Spain

INTRODUCTION

The prognosis of relapsed B cell precursor acute lymphoblastic leukemia (B-ALL) is poor and few patients can be successfully rescued with conventional therapies. Inotuzumab ozogamicin (IO), an antibody against the CD22 antigen linked to calicheamicin, has been approved as a rescue treatment in relapsed/refractory (R/R) B-ALL.

PATIENTS AND METHODS

This was an observational, retrospective, multicenter study of adult patients included in the Spanish program of compassionate use of IO in centers from the PETHEMA group (Programa Español de Tratamientos en Hematología).

RESULTS

Thirty-four patients with a median age of 43 years (range, 19-73) were included. Twenty patients (59%) were refractory to the last treatment, IO treatment was given as ≥3rd salvage treatment in 25 patients (73%) and 20 patients (59%) received allogeneic hematopoietic stem cell transplantation before IO treatment. After a median of 2 cycles of IO, 64% of patients achieved complete response (CR)/complete response with incomplete recovery. The median response duration, progression-free survival and overall survival (OS) were 4.7 (95%CI, 2.4-7.0 months), 3.5 (95%CI, 1.0-5.0 months) and 4 months (95%CI, 1.9-6.1 months) respectively, with better OS for patients with relapsed B-ALL versus refractory disease (10.4 vs. 2.5 months, respectively) (p = .01). There was a trend for better OS for patients with first CR duration >12 months (7.2 months [95%CI, 3.2-11.2] vs. 3 months [95% CI, 1.8-4.2] respectively) (p = .054). There was no sinusoidal obstruction syndrome (SOS) event during IO treatment, but three patients (9%) developed grade 3-4 SOS during alloHSCT after IO treatment.

CONCLUSIONS

Our study showed slightly inferior outcomes of the pivotal trial probably due to poorer risk factors and late onset of IO therapy of recruited patients. Our results support early use of IO in relapsed/refractory ALL patients.

Bone marrow VEGFC expression is associated with multilineage dysplasia and several prognostic markers in adult acute myeloid leukemia, but not with survival

Vascular endothelial growth factor C (VEGFC) stimulates leukemia cell proliferation and survival, and promotes angiogenesis. We studied VEGFC expression in bone marrow samples from 353 adult acute myeloid leukemia (AML) patients and its relationship with several clinical, cytogenetic, and molecular variables. We also studied the expression of 84 genes involved in VEGF signaling in 24 patients. We found that VEGFC expression was higher in AML patients with myelodysplasia-related changes (AML-MRC) than in patients with non-AML-MRC. We also found an association between VEGFC expression and the patient cytogenetic risk group, with those with a worse prognosis having higher VEGFC expression levels. No correlation was observed between VEGFC expression and survival or complete remission. VEGFC expression strongly correlated with expression of the VEGF receptors FLT1, KDR, and NRP1. Thus, in this series, VEGFC expression was increased in AML-MRC and in subgroups with a poorer prognosis, but has no impact on survival.