Tisagenlecleucel versus historical standard therapies for pediatric relapsed/refractory acute lymphoblastic leukemia

Tisagenlecleucel vs. historical standard of care in children and young adult patients with relapsed/refractory B-cell precursor acute lymphoblastic leukemia

In the absence of randomized controlled trials comparing tisagenlecleucel vs. standard of care (SOC) in pediatric and young adult patients with relapsed or refractory acute lymphoblastic leukemia (r/r ALL), the objective was to compare the efficacy of tisagenlecleucel with historical controls from multiple disease registries using patient-level adjustment of the historical controls. The analysis is based on patient-level data of three tisagenlecleucel studies (ELIANA, ENSIGN and CCTL019B2001X) vs. three registries in Germany/Austria. Statistical analyses were fully pre-specified and propensity score weighting of the historical controls by fine stratification weights was used to adjust for relevant confounders identified by systematic literature review. Results showed high comparability of cohorts after adjustment with absolute SMD ≤ 0.1 for all pre-specified confounders and favorable outcomes for tisagenlecleucel compared to SOC for all examined endpoints. Hazard ratios for OS(Intention to treat)ITT,adjusted, EFS(Full analysis set)FAS,naïve and RFSFAS,naïve were 0.54 (95% CI: 0.41-0.71, p < 0.001), 0.67 (0.52-0.86, p = 0.001) and 0.77 (0.51-1.18, p = 0.233). The OSITT, adjusted, EFSFAS,naïve and RFSFAS,naive survival probability at 2 years was 59.49% for tisagenlecleucel vs. 36.16% for SOC population, 42.31% vs. 30.23% and 59.60% vs. 54.57%, respectively. Odds ratio for ORRITT,adjusted was 1.99 (1.33-2.97, p < 0.001). Results for OS and ORR were statistically significant after adjustment for confounders and provide evidence supporting a superiority of tisagenlecleucel in r/r ALL given the good comparability of cohorts after adjustment for confounders.

Case Series of False-Positive HIV Test Results in Pediatric Acute Lymphoblastic Leukemia Patients Following Chimeric Antigen Receptor T-Cell Therapy: Guidance on How to Avoid and Resolve Diagnostic Dilemmas

Chimeric antigen receptor T-cell (CAR-T) Cell Therapy is approved for the treatment of pediatric patients with relapsed/refractory acute lymphoblastic leukemia B-ALL. Lentiviral vector technology, highly modified from HIV-1, is used to induce stable, long-term transgene expression by integration into the host genome. This integration may interfere with HIV-1 NAAT producing false-positive results. Guidance for HIV diagnostic testing in pediatric B-ALL undergoing this type of therapy is lacking. Herein, we report case series with presented scenarios in which HIV-1 NAAT testing among CAR-T cell patients produced false-positive results, highlighting the importance careful assay selection and performance among this patient population.

Indirect comparison of tisagenlecleucel and blinatumomab in pediatric relapsed/refractory acute lymphoblastic leukemia

This study provides the first patient-level data indirect comparison of tisagenlecleucel vs blinatumomab in R/R ALL.

Tisagenlecleucel was associated with a comparatively higher likelihood of achieving CR and a lower hazard of death than blinatumomab.

In the absence of head-to-head trials, an indirect-treatment comparison can estimate the treatment effect of tisagenlecleucel in comparison with blinatumomab on rates of complete remission (CR) and overall survival (OS) in patients with relapsed or primary refractory (R/R) acute lymphoblastic leukemia (ALL). Patient-level data from two pivotal trials, ELIANA (tisagenlecleucel; n = 79) and MT103-205 (blinatumomab; n = 70), were used in comparisons of CR and OS, controlling for cross-trial difference in available patient characteristics. Five different adjustment approaches were implemented: stabilized inverse probability of treatment weight (sIPTW); trimmed sIPTW; stratification by propensity score quintiles; adjustment for prognostic factors; and adjustment for both prognostic factors and propensity score. Comparative analyses indicate that treatment with tisagenlecleucel was associated with a statistically significant higher likelihood of achieving CR and lower hazard of death than treatment with blinatumomab. The tisagenlecleucel group exhibited a higher likelihood of CR than the blinatumomab group in every analysis regardless of adjustment approach (odds ratios: 6.71-9.76). Tisagenlecleucel was also associated with a lower hazard of death than blinatumomab in every analysis, ranging from 68% to 74% lower hazard of death than with blinatumomab, determined using multiple adjustment approaches (hazard ratios: 0.26-0.32). These findings support the growing body of clinical trials and real-world evidence demonstrating that tisagenlecleucel is an important treatment option for children and young adults with R/R ALL.

Toci or not toci: innovations in the diagnosis, prevention, and early management of cytokine release syndrome

Cytokine release syndrome (CRS) remains a significant toxicity of chimeric antigen receptor T-cell (CAR-T) therapy for hematologic malignancies. While established guidelines exist for the management of Grade 2+ CRS with immunosuppressive agents such as tocilizumab or corticosteroids, the management of early-grade CRS (i.e. Grade 1 CRS with isolated fevers) has no such consensus beyond supportive care. In this review, we discuss early-grade CRS with an emphasis on its diagnosis, management, and prevention. Strategies to target early-grade CRS include immunosuppression preemptively (once CRS develops) or prophylactically (before CRS develops) as well as novel small-molecule inhibitors or fractionated CAR-T dosing. In the near future, next-generation CAR-T therapies may be able to target CRS precisely or obviate CRS entirely. If shown to prevent CRS-associated morbidity while maintaining therapeutic anti-neoplastic efficacy, these innovative strategies will enhance the safety of CAR-T therapy while also improving its operationalization and accessibility in the real-world setting.

Cost-Effectiveness Analysis of Tisagenlecleucel for the Treatment of Pediatric and Young Adult Patients with Relapsed or Refractory B Cell Acute Lymphoblastic Leukemia in Japan

Until recently, treatment options were relatively limited for children and young adults with relapsed or refractory (r/r) acute lymphoblastic leukemia (ALL). Tisagenlecleucel is a chimeric antigen receptor T cell (CAR-T) immunotherapy with promising efficacy and manageable safety that was approved in Japan in 2019 for the treatment of CD19-positive r/r B cell ALL (B-ALL). However, there is no publication assessing the cost-effectiveness of CAR-T in Japan. The objective of this study was to assess the cost-effectiveness of a tisagenlecleucel treatment strategy compared to a blinatumomab treatment strategy and a clofarabine combination treatment strategy (i.e., clofarabine + cyclophosphamide + etoposide) in Japan for pediatric and young adult patients up to 25 years of age with r/r B-ALL. A partitioned survival model with a lifetime horizon and monthly cycle was constructed from a Japanese public healthcare payer's perspective. Patients were distributed across the following partitioned health states: event-free survival (EFS), progressive disease, and death, which were informed by the EFS and overall survival (OS) data of respective clinical trials before year 5. For the tisagenlecleucel arm, a decision-tree structure was used to partition patients based on the infusion status; those who discontinued prior to receiving infusion were assigned efficacy and cost inputs of blinatumomab and those who received infusion were assigned efficacy and costs inputs based on tisagenlecleucel-infused patients. As trial data for blinatumomab and clofarabine ended before year 5, matching-adjusted indirect comparisons were used to extrapolate OS between the end of trial observation and up to year 5. All surviving patients followed the mortality risk of long-term ALL survivors without additional risk of disease relapse after year 5, regardless of initial treatment strategies. The model accounted for pretreatment costs, treatment costs, adverse event costs, follow-up costs, subsequent allogeneic hematopoietic stem cell transplantation costs, and terminal care costs. Incremental cost-effectiveness ratios (ICERs) per life-years (LYs) gained and ICERs per quality-adjusted life-years (QALYs) gained were evaluated using a 2% discount rate, and a threshold of ¥7.5 million was used to assess cost-effectiveness. Deterministic and probabilistic sensitivity analyses were performed. The total LYs (discounted) for tisagenlecleucel, blinatumomab, and clofarabine combination treatment strategies were 13.3, 4.0, and 2.7 years, respectively; the corresponding QALYs were 11.6, 3.1, and 2.1 years, respectively. The ICERs per QALY gained for tisagenlecleucel were ¥2,035,071 versus blinatumomab and ¥2,644,702 versus clofarabine combination therapy. Extensive sensitivity analyses supported the findings. Tisagenlecleucel is a cost-effective treatment strategy for pediatric and young adult patients with r/r B-ALL from a Japanese public healthcare payer's perspective.