Don't keep me waiting: estimating the lifetime impact of reduced vein-to-vein time for CAR-T treated patients with LBCL.

Chimeric antigen receptor (CAR) T-cell therapies have revolutionized the treatment of hematological cancers. Production requires a complex logistical process from leukapheresis to patient infusion, the vein-to-vein time (V2VT), during which a patients clinical condition may deteriorate. This study was designed to estimate the benefits of reduced V2VT for third-line+ (3L+) relapsed/refractory large B-cell lymphoma (r/r LBCL) patients treated with CAR T. A mathematical model was developed to estimate the lifetime outcomes of a hypothetical cohort of patients who had either a 'long' or 'short' V2VT. Life-years (LYs), quality-adjusted life years (QALYs), and costs were estimated. Scenario analyses were performed to assess the robustness of results to key assumptions.  The results of the model show that reducing V2VT from 54 days (tisa-cel median V2VT; JULIET) to 24 days (axi-cel median V2VT; ZUMA-1) led to a 3.2-year gain in life expectancy (4.2 vs 7.7 LYs), and 2.4 additional QALYs (3.2 vs 5.6) per patient. Furthermore, a shorter V2VT was shown to be cost-effective under conventional willingness-to-pay thresholds in the United States. Results are driven by a higher infusion rate and and a better efficacy of CAR T-cell therapy for those infused. Scenario analyses using a smaller difference in V2VT (24 vs 36 days) produced consistent results. Our study is the first to quantify lifetime V2VT-related outcomes for 3L+ r/r LBCL patients treated with CAR T utilizing currently available evidence. Shorter V2VTs led to improved outcomes, demonstrating the importance of timely infusion achievable by faster manufacturing times and optimization of hospital delivery.

An updated cost-effectiveness analysis of axicabtagene ciloleucel in second-line large B-cell lymphoma patients in the United States.

AIMS: This economic evaluation of axicabtagene ciloleucel (axi-cel) versus previous standard of care (SOC; salvage chemotherapy followed by high-dose therapy with autologous stem cell rescue) in the second line (2L) large B-cell lymphoma population is an update of previous economic models that contained immature survival data. METHODS: This analysis is based on primary overall survival (OS) ZUMA-7 clinical trial data (median follow-up of 47.2 months), from a United States (US) payer perspective, with a model time horizon of 50 years. Mixture cure models were used to extrapolate updated survival data; subsequent treatment data and costs were updated. Patients who remained in the event-free survival state by 5 years were assumed to have achieved long-term remission and not require subsequent treatment. RESULTS: Substantial survival and quality of life benefits were observed despite 57% of patients in the SOC arm receiving subsequent cellular therapy: median model-projected (ZUMA-7 trial Kaplan-Meier estimated) OS was 78 months (median not reached) for axi-cel versus 25 months (31 months) for SOC, resulting in incremental quality-adjusted life year (QALY) difference of 1.63 in favor of axi-cel. Incrementally higher subsequent treatment costs were observed in the SOC arm due to substantial crossover to cellular therapies, thus, when considering the generally accepted willingness to pay threshold of $150,000 per QALY in the US, axi-cel was cost-effective with an incremental cost-effectiveness ratio of $98,040 per QALY. CONCLUSIONS: Results remained consistent across a wide range of sensitivity and scenario analysis, including a crossover adjusted analysis, suggesting that the mature OS data has significantly reduced the uncertainty of axi-cel's cost-effectiveness in the 2L setting in the US. Deferring treatment with CAR T therapies after attempting a path to transplant may result in excess mortality, lower quality of life and would be an inefficient use of resources relative to 2L axi-cel.

Axicabtagene ciloleucel compared to standard of care in Swedish patients with large B-cell lymphoma: a cost-effectiveness analysis of the ZUMA-7 trial.

AIM: Our study aimed to evaluate the cost-effectiveness of the chimeric antigen receptor (CAR) T-cell therapy, axicabtagene ciloleucel (axi-cel), compared to standard of care (SOC) in Sweden for second-line (2L) treatment of adult transplant-intended diffuse large B-cell lymphoma (DLBCL) patients who relapse within 12 months from completion of, or are refractory to (early r/r), first-line (1L) chemoimmunotherapy. METHODS: Cost-effectiveness was assessed using a three-state partitioned survival model. Mixture cure models were used to extrapolate time-to-event data from the ZUMA-7 trial (NCT03391466) beyond the observational period. Sensitivity and scenario analyses were performed to test the robustness of the base case results, including an analysis that assumed no switching to off-protocol CAR T-cell therapy in subsequent lines in the SOC arm. RESULTS: The model estimated an incremental cost-effectiveness ratio (ICER) of SEK 534,704 (EUR 50,303) per quality-adjusted life year (QALY) gained over a lifetime horizon of 50 years, with an incremental cost of SEK 812,944 (EUR 76,479) and incremental QALY of 1.52 for axi-cel compared with SOC. The probabilistic sensitivity analysis showed that axi-cel was cost-effective in 73% of the simulations when assuming a willingness-to-pay threshold of SEK 1,000,000 (EUR 94,077) per QALY. The ICER was SEK 694,351 (EUR 65,313) in the scenario analysis where the costs and effects of treatment switching were not included. CONCLUSION: 2L treatment with axi-cel in transplant-intended DLBCL patients with early r/r after completing 1L chemoimmunotherapy was cost-effective compared to SOC in a Swedish setting. Administering axi-cel in 2L is cost-effective as it enhances the possibility of curing more patients, resulting in not just a survival advantage, but also a reduction in the burden on quality of life and cost of subsequent therapy. This will be advantageous to both patients and society.

The Cost-Effectiveness of Axicabtagene Ciloleucel as Second-Line Therapy in Patients with Large B-Cell Lymphoma in the United States: An Economic Evaluation of the ZUMA-7 Trial.

Axicabtagene ciloleucel (axi-cel) was found to have superior clinical outcomes compared to standard of care (SOC; salvage chemoimmunotherapy, followed by high-dose therapy with autologous stem cell rescue for responders) for second-line large B-cell lymphoma (2L LBCL) in the pivotal ZUMA-7 trial. The aim of this analysis was to evaluate the cost effectiveness of using axi-cel compared to the current standard 2L LBCL therapy. A 3-state partitioned-survival model estimated the cost effectiveness and budget impact from a payer perspective in the United States. Clinical outcomes were extrapolated based on the pivotal trial. The model calculated expected quality-adjusted life years (QALYs), total costs (in United States dollars [USD], and the incremental cost-effectiveness ratio (ICER), along with the budget impact. Sensitivity and scenario analyses were performed. The proportion alive at 10 years was estimated as 48% for axi-cel and 38% for SOC; median overall survival was estimated at 59 and 24 months for axi-cel and SOC, respectively. Over a lifetime horizon, the model estimated a total of 5.56 and 7.08 QALYs for SOC and axi-cel, respectively, of which 41% and 74% were in the event-free state, respectively. Incremental QALYs and costs were 1.51 and $100,366 USD, resulting in an ICER of $66,381 USD per QALY for axi-cel versus SOC. Despite crossover to subsequent CAR T in the SOC arm, second-line CAR T use was found to improve the quality and length of life compared to SOC. Cost offsets due to subsequent CAR T use led to a limited incremental cost difference. Treatment with axi-cel is a cost-effective option that addresses an important unmet clinical need for patients with LBCL who relapse or are refractory to front-line therapy.

Predicting Survival for Chimeric Antigen Receptor T-Cell Therapy: A Validation of Survival Models Using Follow-Up Data From ZUMA-1.

OBJECTIVES: Survival extrapolation for chimeric antigen receptor T-cell therapies is challenging, owing to their unique mechanistic properties that translate to complex hazard functions. Axicabtagene ciloleucel is indicated for the treatment of relapse or refractory diffuse large B-cell lymphoma after 2 or more lines of therapy based on the ZUMA-1 trial. Four data snapshots are available, with minimum follow-up of 12, 24, 36, and 48 months. This analysis explores how survival extrapolations for axicabtagene ciloleucel using ZUMA-1 data can be validated and compared. METHODS: Three different parametric modeling approaches were applied: standard parametric, spline-based, and cure-based models. Models were compared using a range of metrics, across the 4 data snapshot, including visual fit, plausibility of long-term estimates, statistical goodness of fit, inspection of hazard plots, point-estimate accuracy, and conditional survival estimates. RESULTS: Standard and spline-based parametric extrapolations were generally incapable of fitting the ZUMA-1 data well. Cure-based models provided the best fit based on the earliest data snapshot, with extrapolations remaining consistent as data matured. At 48 months, the maximum survival overestimate was 8.3% (Gompertz mixture-cure model) versus the maximum underestimate of 33.5% (Weibull standard parametric model). CONCLUSIONS: Where a plateau in the survival curve is clinically plausible, cure-based models may be helpful in making accurate predictions based on immature data. The ability to reliably extrapolate from maturing data may reduce delays in patient access to potentially lifesaving treatments. Additional research is required to understand how models compare in broader contexts, including different treatments and therapeutic areas.

Localising occult prostate cancer metastasis with advanced imaging techniques (LOCATE trial): a prospective cohort, observational diagnostic accuracy trial investigating whole-body magnetic resonance imaging in radio-recurrent prostate cancer.

BACKGROUND: Accurate whole-body staging following biochemical relapse in prostate cancer is vital in determining the optimum disease management. Current imaging guidelines recommend various imaging platforms such as computed tomography (CT), Technetium 99 m (99mTc) bone scan and 18F-choline and recently 68Ga-PSMA positron emission tomography (PET) for the evaluation of the extent of disease. Such approach requires multiple hospital attendances and can be time and resource intensive. Recently, whole-body magnetic resonance imaging (WB-MRI) has been used in a single visit scanning session for several malignancies, including prostate cancer, with promising results, providing similar accuracy compared to the combined conventional imaging techniques. The LOCATE trial aims to investigate the application of WB-MRI for re-staging of patients with biochemical relapse (BCR) following external beam radiotherapy and brachytherapy in patients with prostate cancer. METHODS/DESIGN: The LOCATE trial is a prospective cohort, multi-centre, non-randomised, diagnostic accuracy study comparing WB-MRI and conventional imaging. Eligible patients will undergo WB-MRI in addition to conventional imaging investigations at the time of BCR and will be asked to attend a second WB-MRI exam, 12-months following the initial scan. WB-MRI results will be compared to an enhanced reference standard comprising all the initial, follow-up imaging and non-imaging investigations. The diagnostic performance (sensitivity and specificity analysis) of WB-MRI for re-staging of BCR will be investigated against the enhanced reference standard on a per-patient basis. An economic analysis of WB-MRI compared to conventional imaging pathways will be performed to inform the cost-effectiveness of the WB-MRI imaging pathway. Additionally, an exploratory sub-study will be performed on blood samples and exosome-derived human epidermal growth factor receptor (HER) dimer measurements will be taken to investigate its significance in this cohort. DISCUSSION: The LOCATE trial will compare WB-MRI versus the conventional imaging pathway including its cost-effectiveness, therefore informing the most accurate and efficient imaging pathway. TRIAL REGISTRATION: LOCATE trial was registered on ClinicalTrial.gov on 18th of October 2016 with registration reference number NCT02935816.