Pooled safety analysis of tisagenlecleucel in children and young adults with B cell acute lymphoblastic leukemia

BACKGROUND

Tisagenlecleucel, an anti-CD19 chimeric antigen receptor T cell therapy, has demonstrated efficacy in children and young adults with relapsed/refractory B cell acute lymphoblastic leukemia (B-ALL) in two multicenter phase 2 trials (ClinicalTrials.gov, NCT02435849 (ELIANA) and NCT02228096 (ENSIGN)), leading to commercialization of tisagenlecleucel for the treatment of patients up to age 25 years with B-ALL that is refractory or in second or greater relapse.

METHODS

A pooled analysis of 137 patients from these trials (ELIANA: n=79; ENSIGN: n=58) was performed to provide a comprehensive safety profile for tisagenlecleucel.

RESULTS

Grade 3/4 tisagenlecleucel-related adverse events (AEs) were reported in 77% of patients. Specific AEs of interest that occurred ≤8 weeks postinfusion included cytokine-release syndrome (CRS; 79% (grade 4: 22%)), infections (42%; grade 3/4: 19%), prolonged (not resolved by day 28) cytopenias (40%; grade 3/4: 34%), neurologic events (36%; grade 3: 10%; no grade 4 events), and tumor lysis syndrome (4%; all grade 3). Treatment for CRS included tocilizumab (40%) and corticosteroids (23%). The frequency of neurologic events increased with CRS severity (p<0.001). Median time to resolution of grade 3/4 cytopenias to grade ≤2 was 2.0 (95% CI 1.87 to 2.23) months for neutropenia, 2.4 (95% CI 1.97 to 3.68) months for lymphopenia, 2.0 (95% CI 1.87 to 2.27) months for leukopenia, 1.9 (95% CI 1.74 to 2.10) months for thrombocytopenia, and 1.0 (95% CI 0.95 to 1.87) month for anemia. All patients who achieved complete remission (CR)/CR with incomplete hematologic recovery experienced B cell aplasia; however, as nearly all responders also received immunoglobulin replacement, few grade 3/4 infections occurred >1 year postinfusion.

CONCLUSIONS

This pooled analysis provides a detailed safety profile for tisagenlecleucel during the course of clinical trials, and AE management guidance, with a longer follow-up duration compared with previous reports.

Tisagenlecleucel (Tisa) for relapsed/refractory (r/r) acute lymphoblastic leukemia (ALL): B2001X study focusing on prior exposure to blinatumomab (BLINA) and inotuzumab (INO)

10518

Background: B2001X (NCT03123939) is a multicenter global study of tisa to provide access to patients (pts) with r/r ALL including prior anti-CD19 therapy after enrollment ended in the pivotal ELIANA (NCT02435849) study. We report clinical outcomes and cellular kinetics in B2001X including pts with prior BLINA exposure or INO as bridging therapy (BT). Methods: Eligible pts ≤21 y at diagnosis with ≥2 relapse, refractory or post allogeneic transplant (alloSCT) relapse were enrolled globally. Results: As of Nov 4, 2019, 73 pts were enrolled; 67 received tisa. 91% received lymphodepletion. Among 65 pts ≥3 mo follow up (FU) or discontinued earlier (efficacy analysis set [EAS]) median FU was 9.6 mo (range [R] 0.2-16.5). Median age 10 y (R 2-33); prior alloSCT 61%; 15 pts had prior BLINA and 9 pts had INO as BT. Efficacy is summarized in Table. 13/14 relapsed pts were medullary (isolated or combined with extramedullary [EM]) and 1 EM; 9 within 6 mo including 4/5 who were CD19(+). 64% had CRS (G 3/4 13%/15%; Penn scale); 24% had neurologic events (G 3/4 9%/2%; CTCAE v4.03). 4 deaths ≤30 d: 2 early ALL progression, 1 fatal CRS with refractory ALL, 1 infection with multiorgan failure. Transgene level in peripheral blood: limited to no in vivo expansion in nonresponders (n=8) vs responders (n=42). Median duration of persistence (T last) of tisa was 272 d (R 27-379) in responders. In pts with CR/CRi, Cmax (geo-mean [CV%]) and median T last were 9260 (124) copies/µg DNA and 154 d (R 28-349), respectively, in pts who received INO as BT (n=6) vs 38,500 (215) and 273 d (R 27-379), respectively, in pts with no INO as BT (n=36). Conclusions: Outcomes in B2001X remain consistent with ELIANA. In pts with prior BLINA or INO as BT, a trend toward suboptimal outcomes was observed but should be interpreted with caution due to small n, short FU and potential confounding factors. Clinical trial information: NCT03123939. [Table: see text]

Rare form of autosomal dominant thalassemia--hemoglobin Hakkari

Autosomal dominant Beta Thalassemias are rare and are due to point or frame shift mutations resulting in production of abnormal unstable beta chains of hemoglobin which precipitate leading to hemolysis and anemia. We describe a case of Hemoglobin Hakkari, a rare variant of dominant Thalassemia arising due to a de novo mutation in the exon 2 of the beta globin gene.

Late effects in hematopoietic cell transplant recipients with acquired severe aplastic anemia: a report from the late effects working committee of the center for international blood and marrow transplant research

With improvements in hematopoietic cell transplant (HCT) outcomes for severe aplastic anemia (SAA), there is a growing population of SAA survivors after HCT. However, there is a paucity of information regarding late effects that occur after HCT in SAA survivors. This study describes the malignant and nonmalignant late effects in survivors with SAA after HCT. A descriptive analysis was conducted of 1718 patients post-HCT for acquired SAA between 1995 and 2006 reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). The prevalence and cumulative incidence estimates of late effects are reported for 1-year HCT survivors with SAA. Of the HCT recipients, 1176 (68.5%) and 542 (31.5%) patients underwent a matched sibling donor (MSD) or unrelated donor (URD) HCT, respectively. The median age at the time of HCT was 20 years. The median interval from diagnosis to transplantation was 3 months for MSD HCT and 14 months for URD HCT. The median follow-up was 70 months and 67 months for MSD and URD HCT survivors, respectively. Overall survival at 1 year, 2 years, and 5 years for the entire cohort was 76% (95% confidence interval [CI]: 74-78), 73% (95% CI: 71-75), and 70% (95% CI: 68-72). Among 1-year survivors of MSD HCT, 6% had 1 late effect and 1% had multiple late effects. For 1-year survivors of URD HCT, 13% had 1 late effect and 2% had multiple late effects. Among survivors of MSD HCT, the cumulative incidence estimates of developing late effects were all <3% and did not increase over time. In contrast, for recipients of URD HCT, the cumulative incidence of developing several late effects exceeded 3% by 5 years: gonadal dysfunction 10.5% (95% CI: 7.3-14.3), growth disturbance 7.2% (95% CI: 4.4-10.7), avascular necrosis 6.3% (95% CI: 3.6-9.7), hypothyroidism 5.5% (95% CI: 2.8-9.0), and cataracts 5.1% (95% CI: 2.9-8.0). Our results indicated that all patients undergoing HCT for SAA remain at risk for late effects, must be counseled about, and should be monitored for late effects for the remainder of their lives.