A Real-world Study of the Effectiveness of Tisagenlecleucel in Acute Lymphoblastic Leukemia Patients

Remission rate was defined as the best overall response as either complete remission (CR) or complete remission with incomplete blood count recovery (CRi) to tisa-cel.

CR: <5% blasts in bone marrow based on morphologic assessment, no evidence of extramedullary disease, full recovery of peripheral blood counts (platelets > 100x10^9/L, absolute neutrophil > 1.0x10^9/L, and circulating blasts <1%), and blood transfusions independency (i.e., no transfusion or transfusion ≤7 days).

CRi: <5% blasts in bone marrow, no evidence of extramedullary disease, but without full recovery of peripheral blood counts with or without blood transfusions independency.

Demographic categories included:

• Age group
• Gender
• Race
• Ethnicity
• Geographical region
• Distance between residence and referral center (<5, 5-30, 30-60, >60 miles)
• Type of insurance

Disease characteristics categories included:

• Relapse or refractory status before tisa-cel infusion
• CD19 tumor expression among relapsed patients before tisa-cel infusion
• Karnofsky or Lansky performance score (PS)
• Lymphoblast proportion in bone marrow (<5%, >= 5%)
• Conditions of interest before tisa-cel infusion
• Patients with relapse before tisa-cel infusion
• Number and type of relapse before tisa-cel infusion (any bone marrow and/or central nervous system relapse)
• Cytogenic testing performed at tisa-cel infusion
• Cytogenic abnormalities at tisa-cel infusion
• Number of distinct cytogenic abnormalities (1, 2, 3, 4+)
• Comorbidities at tisa-cel infusion
• Remission status at time of tisa-cel infusion

The Karnofsky and Lansky PS are measures of functional impairment. They run from 0 to 100, where 0 is death and 100 is normal health. The Karnofsky scale is for patients aged 16 years or older. The Lansky scale is for patients younger than 16 years old.

Treatment characteristic categories included:

• Treatments of interest before tisa-cel infusion
• Number of prior lines of treatment category (1 to 7)
• Received prior allogenic stem cell transplant (alloSCT)
• Number of alloSCT received (0, 1, 2)
• Year of initial tisa-cel infusion
• Bridging treatment agent received before tisa-cel infusion
• Lymphodepleting regimen received before tisa-cel infusion
• Type of tisa-cel infusion dose received (single, multiple)
• Weight at tisa-cel infusion (<= 50 kilograms [kg], >50 kg)

Time intervals: <18 months, 18-36 months, and >36 months.

Number of doses for initial infusion was measured among those who received multiple doses.

Bone marrow MRD is a measure of the number of cancer cells remaining in the body after treatment. The number of patients overall with bone marrow MRD negative and those who achieved CR or CRi response with bone marrow MRD negative after tisa-cel infusion was measured. Bone marrow MRD negative was based on clinical assessment by the investigator.

CR: <5% blasts in bone marrow based on morphologic assessment, no evidence of extramedullary disease, full recovery of peripheral blood counts (platelets > 100x10^9/L, absolute neutrophil > 1.0x10^9/L, and circulating blasts <1%), and blood transfusions independency (i.e., no transfusion or transfusion ≤7 days).

CRi: <5% blasts in bone marrow, no evidence of extramedullary disease, but without full recovery of peripheral blood count with or without blood transfusions independency.

DOR was defined as the time from onset of remission to relapse or death due to ALL.

Relapse was defined as:

• Reappearance of blasts in the blood (≥1%), or
• Reappearance of blasts in bone marrow (≥5%), or
• Appearance of any extramedullary disease

RFS was defined as the time from onset of remission to relapse or death due to any cause.

Relapse was defined as:

• Reappearance of blasts in the blood (≥1%), or
• Reappearance of blasts in bone marrow (≥5%), or
• Appearance of any extramedullary disease

EFS was defined as the time from tisa-cel infusion to the earliest of the following events: death due to any cause, relapse, treatment failure (i.e., no response), or new anticancer therapy for ALL (i.e., treatments other than tisa-cel or SCT).

Relapse was defined as:

• Reappearance of blasts in the blood (≥1%), or
• Reappearance of blasts in bone marrow (≥5%), or
• Appearance of any extramedullary disease

OS was defined as the time from tisa-cel infusion to the date of death due to any cause.

Patient counts were categorized by:

• Pre-planned/not pre-planned at time of tisa-cel infusion
• Achieved/had not achieved B-cell recovery at time of alloSCT
• Unknown B-cell recovery status
• Did not have B-cell aplasia
• alloSCT received within 12 months after tisa-cel infusion
• Relapse status after tisa-cel infusion before alloSCT

Patient counts were categorized by:

• Received/did not receive reinfusion
• Received infusion within 12 months after initial infusion
• Reason for reinfusion

B-cell aplasia status included:

• Experienced B-cell aplasia
• Recovered from B-cell aplasia

Ig replacement therapy use was categorized as follows:

• Received Ig replacement therapy
• Received intravenous immunoglobulin (IVIG) therapy
• Ongoing IVIG therapy
• Stopped IVIG therapy
• Received subcutaneous immunoglobulin (SCIG) therapy
• Ongoing SCIG therapy
• B-cell aplasia recovered

Ig replacement therapy included IVIG and SCIG.

Ig replacement therapy included IVIG and SCIG.

Hospitalization categories included not hospitalized, hospitalized for Tisa-cel infusion, and subsequently admitted to intensive care unit (ICU).

Hospitalization categories included hospitalized, not hospitalized, and first hospitalization.

ICU admission categories included admitted to ICU, not admitted to ICU, and first ICU admission.