Investigator Initiated Study to Assess the Safety of Combination of CLS-015 With Anti-CD-19 CAR-T Cells in Patients With Stable/Progressive Large B Cell Lymphoma at Lymphodepletion.

Inclusion Criteria: * Participant must be at least 18 years of age inclusive, at the time of signing the informed consent. * Large B-Cell lymphoma treated with CAR-T targeting CD19 (tisagenlecleucel, axicabtagene ciloleucel, or lisocabtagene maraleucel) * Stable Disease or Progressive Disease confirmed by PET-CT on the day of lymphodepletion * Capable of giving signed informed consent * Eastern Cooperative Oncology Group (ECOG) performance status of 0-2 Exclusion Criteria: * Hypersensitivity to CLS-015 * Evidence of any clinically significant condition, disorder, condition, or disease that, in the opinion of the Investigator would pose a risk to subject safety or interfere with the study evaluation, procedures or completion. * Active infection requiring antibiotics * Females only: Pregnant or breastfeeding