Protocol amendment 1 occurred before the study was initiated at any site. An interim analysis was added once the first DLBCL 50 patients were treated and followed up for 6 months; A safety run-in stage was conducted at the start of the study to enroll at least 3 patients to assess the acute safety profile and product characteristics of the Novartis manufactured tisagenlecleucel cell product; Exploratory endpoints which did not impact the overall sample collection requirements were added; The inclusion and exclusion criteria were modified to ensure a homogenous population; Language in the protocol was changed to be consistent with the approved tisagenlecleucel standard protocol language; protocol language associated with discontinuation from the clinical trial was updated.

The protocol was amended mainly to implement clarifications in line with health authority feedback and to incorporate recent experience from the University of Pennsylvania (Penn) study CTL019A2101J/UPCC13413; At the time of this amendment, 7 patients had been enrolled. None of the enrolled patients would have been excluded from the trial had the amendment been in place prior to enrollment.

The PET-CT was specified to be performed within 4 weeks of infusion but prior to start of lymphodepleting therapy. During the startup of the trial, it became evident that the baseline PET-CT required at screening could often be too far out from the actual tisagenlecleucel infusion to serve as a valid baseline for subsequent response assessments; It was clarified that at least one sentinel vial must be shipped together with the leukapheresis product.

At the time of this amendment, 72 patients were enrolled and 29 patients were treated. Under the protocol version 03, patients with manufactured cell numbers falling below the target dose and acceptable dose ranges for this study were eligible to receive tisagenlecleucel therapy if the product met all other manufacturing release criteria. Preliminary dose expansion analyses suggested that these very low doses showed only minimal in vivo expansion and that patients were very unlikely to derive clinical benefit. Consequently, tisagenlecleucel doses lower than the protocol-specified range were no longer released. One additional study cohort was added: Cohort A aimed to assess efficacy and safety and characterize the in vivo cellular PK profile of tisagenlecleucel manufactured at the Fraunhofer Institut für Zelltherapie, Leipzig, Germany.

At the time of enrollment completion in the Main Cohort, 3 Japanese patients were enrolled, treated, and in primary follow-up. Based on statistical considerations, a minimum of 9 Japanese patients were required to be treated to allow evaluation of the safety and efficacy of tisagenlecleucel in the Japanese patient population. Amendment 5 was implemented to allow enrollment of approximately 10 additional Japanese patients in the Main Cohort, to allow at least 6 additional patients to be treated, to ensure a minimum of 9 and maximum of 13 Japanese patients were treated with tisagenlecleucel.

At the time of this amendment, enrollment to the Main Cohort and Cohort A was completed. The main reasons for Amendment 6 were: To change the required follow-up time for a newborn after live birth from 6 months to 12 months following pregnancy of a female patient or the partner of any male patient. This additional safety monitoring was not due to any new safety concern or emerging data but was added on a precautionary basis and aligned with current Novartis internal guidelines; To update the protocol safety language to reflect the current Novartis tisagenlecleucel program safety language; this included updates to the Potential Toxicities Section as well as updates to the highly effective contraceptive methods in a newly added Contraception Section; To add the requirement for urine or serum pregnancy testing at all study visits to align with standard tisagenlecleucel monitoring requirements. Changes to the Visit Evaluation Schedule were made starting at Month 30 and after all remaining patients were past the Month 30 follow-up; To add language on secondary malignancies and to follow up to align with the tisagenlecleucel program standard language; To specify that blood samples for RCL testing were banked beyond month 12, as long as all samples through Month 12 were negative.