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DURABLE LONG-TERM SURVIVAL OF ADULT PATIENTS WITH B-ALL AFTER CD19 CAR (19-28Z) T CELL THERAPY
Author(s): ,
Jae Park
Affiliations:
MEMORIAL SLOAN-KETTERING CANCER CENTER,New York,United States
,
Isabelle Riviere
Affiliations:
MEMORIAL SLOAN-KETTERING CANCER CENTER,New York,United States
,
Xiuyan Wang
Affiliations:
MEMORIAL SLOAN-KETTERING CANCER CENTER,New York,United States
,
Brigitte Senechal
Affiliations:
MEMORIAL SLOAN-KETTERING CANCER CENTER,New York,United States
,
Yongzeng Wang
Affiliations:
MEMORIAL SLOAN-KETTERING CANCER CENTER,New York,United States
,
Terrence Purdon
Affiliations:
MEMORIAL SLOAN-KETTERING CANCER CENTER,New York,United States
,
Renier Brentjens
Affiliations:
MEMORIAL SLOAN-KETTERING CANCER CENTER,New York,United States
Michel Sadelain
Affiliations:
MEMORIAL SLOAN-KETTERING CANCER CENTER,New York,United States
(Abstract release date: 05/18/17) EHA Library. Smith E. 06/24/17; 181766; S479
Eric Smith
Eric Smith
Contributions
Abstract

Abstract: S479

Type: Oral Presentation

Presentation during EHA22: On Saturday, June 24, 2017 from 16:45 - 17:00

Location: Hall E

Background

CD19-specific chimeric antigen receptor (CAR) T cells have demonstrated high initial responses in patients with relapsed B-ALL.  However, clinical characteristics associated with the durability of response remain undefined.  

Aims
We performed a retrospecive analysis of our phase I clinical trial of 19-28z CAR T cells in adult patients with relapsed B-ALL (NCT01044069) with a focus to identify those patients who optimally benefit from 19-28z CAR T cell therapy with durable long-term survival and reduced toxicities.  

Methods
Adults with relapsed B-ALL were infused with autologous T cells expressing the 19-28z CAR following conditioning chemotherapy. Disease burden was assessed by bone marrow biopsy immediately prior to T cell infusion; patients with <5% blasts were classified as minimal residual disease (MRD) cohort vs. patients ≥5% blasts as morphologic disease cohort.  Response assessment occurred at 4 weeks.  Median follow-up duration was 18 months (range, 0.2-57.3).

Results
51 adults received 19-28z CAR T cells; 20 in the MRD and 31 in the morphologic cohort. Complete remission (CR) rates were comparable (95% and 77%, respectively). However, median event-free and overall survivals widely diverged among the 42 patients who achieved MRD-negative CR: not reached (NR) (95% confidence interval [CI]: 4.2-NR) vs. 6.3 months (95% CI, 4.8-9.0) (p=0.0005), and NR (95% CI, 15.3-NR) vs. 17 months (95% CI, 8.5 – 36.2) (p=0.0189), in the MRD and morphologic cohorts, respectively. Subsequent allogeneic HSCT in either cohort did not improve survival (p=0.8). MRD cohort patients developed substantially less severe cytokine release syndrome (CRS) and neurotoxicity, and both toxicities significnatly correlated with peak CAR T cell expansion (p=0.0326 and p=0.0001, respectively). No case of cerebral edema was observed.

Conclusion

Despite comparable initial CR rates regardless of pre-treatment disease burden, durability of 19-28z CAR T cell mediated remissions and survival in adult patients with relapsed B-ALL positively correlated to a low disease burden and do not appear to be enhanced by allogeneic transplant. Our findings strongly support the early incorporation of CD19 CAR therapy before morphologic relapse in B-ALL.  

Session topic: 2. Acute lymphoblastic leukemia - Clinical

Keyword(s): Gene therapy, Cellular therapy, CD19, Acute lymphoblastic leukemia

Abstract: S479

Type: Oral Presentation

Presentation during EHA22: On Saturday, June 24, 2017 from 16:45 - 17:00

Location: Hall E

Background

CD19-specific chimeric antigen receptor (CAR) T cells have demonstrated high initial responses in patients with relapsed B-ALL.  However, clinical characteristics associated with the durability of response remain undefined.  

Aims
We performed a retrospecive analysis of our phase I clinical trial of 19-28z CAR T cells in adult patients with relapsed B-ALL (NCT01044069) with a focus to identify those patients who optimally benefit from 19-28z CAR T cell therapy with durable long-term survival and reduced toxicities.  

Methods
Adults with relapsed B-ALL were infused with autologous T cells expressing the 19-28z CAR following conditioning chemotherapy. Disease burden was assessed by bone marrow biopsy immediately prior to T cell infusion; patients with <5% blasts were classified as minimal residual disease (MRD) cohort vs. patients ≥5% blasts as morphologic disease cohort.  Response assessment occurred at 4 weeks.  Median follow-up duration was 18 months (range, 0.2-57.3).

Results
51 adults received 19-28z CAR T cells; 20 in the MRD and 31 in the morphologic cohort. Complete remission (CR) rates were comparable (95% and 77%, respectively). However, median event-free and overall survivals widely diverged among the 42 patients who achieved MRD-negative CR: not reached (NR) (95% confidence interval [CI]: 4.2-NR) vs. 6.3 months (95% CI, 4.8-9.0) (p=0.0005), and NR (95% CI, 15.3-NR) vs. 17 months (95% CI, 8.5 – 36.2) (p=0.0189), in the MRD and morphologic cohorts, respectively. Subsequent allogeneic HSCT in either cohort did not improve survival (p=0.8). MRD cohort patients developed substantially less severe cytokine release syndrome (CRS) and neurotoxicity, and both toxicities significnatly correlated with peak CAR T cell expansion (p=0.0326 and p=0.0001, respectively). No case of cerebral edema was observed.

Conclusion

Despite comparable initial CR rates regardless of pre-treatment disease burden, durability of 19-28z CAR T cell mediated remissions and survival in adult patients with relapsed B-ALL positively correlated to a low disease burden and do not appear to be enhanced by allogeneic transplant. Our findings strongly support the early incorporation of CD19 CAR therapy before morphologic relapse in B-ALL.  

Session topic: 2. Acute lymphoblastic leukemia - Clinical

Keyword(s): Gene therapy, Cellular therapy, CD19, Acute lymphoblastic leukemia

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