CAR T cell therapy in patients who have undergone previous anti-cancer alkylating agent therapy

Provided herein are uses of chimeric antigen receptors (CARs) for the treatment of tumors or cancers, such as B-cell associated cancers, such as multiple myeloma. Further, an optimal clearance period for starting a therapy to treat a condition in a subject after previous exposure may be determined by receiving previous treatment history data for each of a plurality of subjects. Left-censored data may then be derived from previous treatment history data for each subject, the left-censored data including a clearance period and an event or censored. A time scale of the left punctured therapy data is then inverted to produce right punctured therapy data. The right-censored therapy data is then applied to a time-event (TTE) model that associates one or more variables of interest with the time since exposure to a previous exposure. For consecutive variables within the one or more variables of interest, a maximum selection logarithmic rank statistic over a plurality of cutoff values within a predefined percentile ra