Notable Labs, Ltd. presented data related to innovations in the use of cryopreserved samples in the PPMP assay at the American Association for Cancer Research (AACR 2024) being held in San Diego, CA (Poster abstract 2548). The study was designed to evaluate the potential use of cryopreserved samples as an alternative to fresh samples for predicting treatment response in acute myeloid leukemia (AML) using Notable?s PPMP. Cryopreserved samples are known for exhibiting low sample viability and cell recovery, rendering their practical utilization challenging Notable adapted an existing methodology to process cryopreserved patient-derived leukemia cells to investigate their use as an alternative to fresh samples in the PPMP assay First, a method was established using freshly isolated white blood cells (WBCs) from AML patients (<2 days from sample collection).

A fraction of these cells was cryopreserved. Both fresh and cryopreserved cells (after thawing and culturing) were assessed on the PPMP and results compared. Second, the established method was applied to cryopreserved samples (from a biobank) collected from AML patients prior to their treatment with chemotherapy (cytarabine plus idarubicin).

Results obtained on the PPMP were compared to the clinical responses experienced by the patients after treatment with cytarabine and idarubicin. For the method development study, ex vivo responses to 3 different compounds (venetoclax, 5-azacytidine and decitabine) were assessed after culturing of the cryopreserved cells for 24- and 48-hour post thaw using two different media (?A? and ?B?). There was a strong correlation (R2 from 0.77 to 0.92) for venetoclax and 5-azacytidine between the results obtained with fresh vs.

frozen samples. For the biobank samples treated with cytarabine and idarubicin, culture media A and B show a similar dose-response behavior. Importantly, the PPMP correctly predicted clinical responders (complete remission) and non-responders (refractory).

While Notable will continue to evaluate and validate these sample handling methodologies, these data open the door to the use of cryopreserved samples from retrospective cohorts.