Screening study (
tumor, MRCLS
TUMOR, SOLID TUMORS
A screening study was initiated to pre-screen patients ≥18 years to ≤75 years of age with advanced solid tumors for the presence of inclusion and exclusion alleles (For MAGE-A4 antigen expression, centralized testing by IHC was performed at HistoGeneX using an analytically validated and clinical laboratory improvement amendments (CLIA)-certified clinical trial assay. Positivity was determined by a pathologist based on the percentage of positive cells and intensity of expression, as determined by a percent score (P-score) (range, 0–100%) for IHC staining. P-score was defined as stained cell percentage at 1+ intensity + stained cell percentage at 2+ intensity + stained cell percentage at 3+ intensity. During the conduct of patient pre-screening in the expansion group, the study protocol was amended for SS and MRCLS to use a higher cutoff of ≥30% of cells that were of 2+ and/or 3+ intensity; a subsequent amendment was made to use this higher cutoff for all other tumor types in the expansion group. For translational data analyses, MAGE-A4 expression was presented as an H-score, which was defined as: (% stained cells at 0) × 0 + (% stained cells at 1+) × 1 + (% stained cells at 2+) × 2 + (% stained cells at 3+) × 3. The H-score range is 0–300 (refs. 