Delays from Progression to Initial Appointment Occur with External Referrals for CAR T-Cell Therapy but Do Not Impact Survival

• Published in: Blood 2024-11, Vol.144, p.7581-7581
• Main Authors: Bhella, Sita D., Hueniken, Katrina, Jarallah, Osamah Jamal S., Maltez, Melissa Teixeira, Aitken, Rachel, Waldron, Carmel, Crump, Michael, Kuruvilla, John, Prica, Anca, Kukreti, Vishal, Kridel, Robert, Vijenthira, Abi, Yang, Chloe, Tsang, Richard, Hodgson, David, Rodin, Danielle, Malik, Nauman, Wells, Woodrow, Chen, Christine I
• Format: Article
• Language: English
• ISSN: 0006-4971
• DOI: 10.1182/blood-2024-211007

Background Princess Margaret (PM) is the referral centre for antiCD19 CAR T-cell therapy (CART) for a large regional, provincial and national population. We sought to determine if patients referred from out of province (OOP) or from centres in province but external to our centre (EIP) experienced delays in treatment, inferior survival or increased toxicity compared to local populations (LIP). Methods: This is a single-centre retrospective review of consecutive patients with RR-LBCL referred for CART at PM from April 2020-November 2023 for ³ 3rd line therapy. Outcomes included progression-free survival (PFS) defined from date of cell infusion/ date of intake (for pts that failed to proceed with CART (PFPC)) to PD/death/last follow-up. Overall survival (OS) defined from date of cell infusion/date of intake (for PFPC) to death/last follow-up. Metrics to infusion were examined including dates of: CT demonstrating progression post 2L+ therapy, referral, intake, apheresis and infusion. Toxicity outcomes included rates of CRS, ICANS, use of tocilizumab/steroids/ICU and non-relapse mortality. Results: 238 consecutive patients were included for analysis, with 183 receiving CART and 55 who were referred but did not receive CART (no CART). No significant difference in baseline characteristics between LIP,EIP and OOP cohorts were seen: median age(yrs) (58.6,60.1,61.8, p=0.19), % male (62,63,61, p=0.96), % stage 3-4 (81,75,88,p=0.27), % bulky disease > 7 cm (46,42,33,p=0.30), % extranodal disease (59,54,59,p=0.78), % history of CNS disease (7,8,4,p=0.71, % refractory disease (59,66,64,p=0.67) and % treated with autologous stem cell transplant (29,24,27,p=0.78). EIP pts had a significantly higher ECOG 2+ population as % with ECOG 2+ was LIP 20%, EIP 38% and OOP 15% (p=0.001). 19% received tisa-cel, 58% received axi-cel and 23% received no CART (p=0.27). 167 (70%) pts were referred from Ontario (78 EIP and 89 LIP) and 71 (30%) were from out of province (OOP). When comparing Ontario to OOP pts, 77.8% v. 74.6% of referrals received CART. 84.3% of LIP compared to 70.5% of EIP referrals received CART (p=0.095). Bridging was used in 73% Ontario pts compared to 59% OOP pts (p=0.046). Date of CT demonstrating progression to initial visit for the whole cohort was a median of 11 days (0-177) for LIP, 16 days (0-189) for EIP and 22 days (0-113) for OOP (p