Spearhead 1 Study in Subjects With Advanced Synovial Sarcoma or Myxoid/Round Cell Liposarcoma

Percentage of participants with confirmed tumor response (complete \[CR\] or partial \[PR\] response) to treatment as assessed using Response Evaluation Criteria in Solid Tumors (RECIST) v1.1 by Independent Radiologist review (Cohort 1)

Time frame: From T-cell infusion until disease progression/recurrence as of data cut off (up to 2 years). Response was assessed at Week 4, Week 8, Week 12, Week 16, and Week 24, and every 2 months +/- 28 days until confirmed disease progression.

Population: Participants who received afamitresgene autoleucel

An AE was defined as any untoward medical occurrence in a subject or clinical study participant temporally associated with the use of the study intervention, whether or not considered related to the study intervention. Therefore, an AE could have been any unfavorable and unintended sign (including an abnormal laboratory finding), symptom, or disease (new or exacerbated) temporally associated with the use of study intervention. The number of participants with AEs (including SAE), SAE and AESI including cytokine release syndrome, neurotoxicity, ICANS, prolonged cytopenia are presented.

Time frame: AEs, SAEs, and AESIs were collected at each visit from the start of lymphodepletion of the first subject until the last subject discontinued the interventional phase in cohort 1 as of the safety cut off (up to 3.2 years).

Population: Participants who received afamitresgene autoleucel

BOR is the best response recorded from the start of T-cell infusion until disease progression/recurrence as assessed by Independent Radiologist review. Response categories are confirmed CR, confirmed PR, stable disease and confirmed progressive disease (PD). Best overall response is a stable disease, if CR or PR are unconfirmed.

Time frame: From T-cell infusion until disease progression/recurrence as of data cut off (up to 2.6 years). Response was assessed at Week 4, Week 8, Week 12, Week 16, and Week 24, and every 2 months +/- 28 days until confirmed disease progression.

Population: Participants who received afamitresgene autoleucel

DoR (in months) is defined as ((date of PD (or censoring) - date of initial confirmed CR/PR + 1)/365.25)\*12 as assessed by Independent Radiologist review. Outcome Measure not yet reached as participants are ongoing in study

Time frame: From initial confirmed response (CR or PR) until PD (or censored date) as of data cut off.

Deoxyribonucleic acid (DNA) from participants peripheral blood mononuclear cell (PBMC) samples was subjected to lentiviral vector integration site analysis by next-generation sequencing, thus evaluating both the clonality status of the transduced cell population and the genomic localization of individual integration sites. The count of participants with integration sites representing more than 5% of all unique sites is presented.

Time frame: From 10 months post T-cell infusion up to 20 months post T-cell infusion (as of the data cut off)

Population: Participants who received afamitresgene autoleucel and had a sample analyzed for IO

Development and validation of the MAGE-A4 antigen expression companion diagnostic assay

Time frame: 2.5 years

OS is defined as the time from the date of T-cell infusion to the date of death (due to any reason) or censored date. OS in months was calculated as ((death date - first T-cell infusion date + 1)/365.25)\*12. Outcome Measure not yet reached as participants are ongoing in study

Time frame: From T-cell infusion to death due to any reason (or censored date) as of data cut off (up to 2.6 years).

Peak persistence of afamitresgene autoleucel cells was reported as vector copy numbers per microgram of genomic DNA from peripheral blood mononuclear cell (PBMC).

Time frame: From T-cell infusion to 3.2 years (as of data cut off).

Population: Participants who received afamitresgene autoleucel

PFS is defined as the time from T-cell infusion to the date of the first documentation of PD or death due to any cause, whichever occurs first, as assessed by Independent Radiologist review. PFS (in weeks) was calculated as (date of PD/death \[or censored date\] - first T-cell infusion date + 1)/7.

Time frame: From T-cell infusion until first documented PD or death due to any cause (or censored date), whichever occurs first, as of data cut off (up to 2.6 years). Response was assessed at Week 4, 8,12,16, 24, and every 2 months until confirmed PD

Population: Participants who received afamitresgene autoleucel

Quantitation of genetically engineered T-cells in PBMCs by flow cytometry

Time frame: 2.5 years

The presence of RCL was assessed by qPCR targeting a segment of the vesicular stomatitis virus glycoprotein (VSV G) coding sequence.

Time frame: From T-cell infusion to months 3, 6, and 12 post-infusion, then annually post-infusion (up to 2.8 years as of the data cut off).

Population: Participants who received afamitresgene autoleucel and had a sample tested for VSV-G by qPCR (RCL) at or after 3 months post-infusion

Time taken to achieve peak expansion of genetically engineered T-cells in PBMCs by flow cytometry

Time frame: 2.5 years

Time taken to achieve peak expansion of genetically engineered T-cells in PBMCs by qPCR

Time frame: 2.5 years

TTR was defined as the interval (weeks) from the date of T-cell infusion to the earliest date of the first documented confirmed CR or confirmed PR as assessed by Independent Radiologist review. TTR (in weeks) = \[date of initial confirmed CR or PR - date of T-cell infusion + 1\]/7.

Time frame: From T-cell infusion until first documented confirmed CR or confirmed PR. Response was assessed at Week 4, Week 8, Week 12, Week 16, and Week 24, and every 2 months +/- 28 days until confirmed disease progression.

Population: Participants who received afamitresgene autoleucel and had a confirmed CR or confirmed PR as of data cut off.