A Phase 1 interventional study of P-CD19CD20-ALLO1 and Rimiducid in Diffuse Large B-Cell Lymphoma, Not Otherwise Specified, High-grade B-cell Lymphoma and Primary Mediastinal Large B-cell Lymphoma (PMBCL), sponsored by Poseida Therapeutics, Inc.. Active, not recruiting at 16 sites in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2026-05-07.
Sponsored by Poseida Therapeutics, Inc. · Phase 1, Interventional, and Treatment
Phase 1 study comprised of open-label, dose escalation and expansion cohort study of P-CD19CD20-ALLO1 allogeneic T stem cell memory (Tscm) CAR-T cells in subjects with relapsed/refractory B cell malignancies
Phase 1 study consisting of two parts. Part 1 is a weight-based dose escalation following a 3+3 design of dose-escalating cohorts to define a maximum tolerated dose (MTD). Part 2 includes administration at a selected dose and LD regimen. After enrollment, subjects will receive a lymphodepletion therapy regimen before administration of allogeneic CAR-T cells, administered as a single dose. Treated subjects will undergo serial measurements of safety, tolerability and response. Rimiducid may be administered.
Must have relapsed/refractory disease and have received adequate prior anti-cancer therapy, as defined below:
a. Prior systemic chemotherapy must include a line of chemoimmunotherapy that includes an anti-CD20 antibody, an anthracycline, and 1 or more of the following: i. No response to first-line therapy (primary refractory disease). Refractory disease (defined as SD, PD, PR or CR with relapse before 3 months).
ii. Progressive disease following two or more lines of therapy. However, SD as the best response after at least 2 cycles of the last line of therapy with SD duration no longer than 6 months from the last dose of therapy is also acceptable.
iii. Refractory post-autologous stem cell transplant (ASCT). Disease progression or relapse occurring at less than or equal to 12 months of undergoing ASCT (must have biopsy proven recurrence in relapsed patients). If salvage therapy is given post-ASCT, the patient must have had no response to or relapsed after the last line of therapy.
iv. Refractory disease (SD, PD, PR or CR with relapse before 3 months) or relapsed disease (defined as CR/PR with relapse on, or after lasting at least 3 months but no more than 12 months), to CD20 antibody and anthracycline containing first-line therapy.
Must have adequate vital organ function, defined as follows (or medical monitor approval):
i. Absolute neutrophil count (ANC) ≥ 1000/μL in the absence of growth factor support (granulocyte colony stimulating factor [G-CSF] within 7 days or peg-G-CSF within 14 days) ii. Platelet count ≥ 50,000/μL in the absence of transfusion support (platelet transfusion within 7 days) iii. Hemoglobin ≥ 8 g/dL in the absence of transfusion support (red blood cell count or whole blood within 7 days) c. Aspartate transaminase (AST) and alanine aminotransferase (ALT) ≤ 3 × the upper limit of normal (ULN), and total bilirubin ≤ 2.0 mg/dL (unless there is a history of Gilbert's Syndrome in which case bilirubin levels ≤ 3 mg/dL).
d. Left ventricular ejection fraction (LVEF) ≥ 45%. LVEF assessment must have been performed within 4 weeks of enrollment.
Exclusion Criteria
P-CD19CD20-ALLO1 following conditioning chemotherapy regimen S. Rimiducid may be administered.
Biological: P-CD19CD20-ALLO1 · Drug: Rimiducid
P-CD19CD20-ALLO1 following conditioning chemotherapy regimen LD 750. Rimiducid may be administered.
Biological: P-CD19CD20-ALLO1 · Drug: Rimiducid
P-CD19CD20-ALLO1 following conditioning chemotherapy regimen LD 1000. Rimiducid may be administered.
Biological: P-CD19CD20-ALLO1 · Drug: Rimiducid
Single weight-based IV administration
Single weight-based IV administration
Assess the safety and MTD or RDE of P-CD19CD20-ALLO1 based on dose limiting toxicities (DLT)
Rate of DLT's
Time frame: Baseline through 28 days
The safety of P-CD19CD20-ALLO1 (AEs)
Incidence and severity of adverse events (AEs)
Time frame: Baseline through 36 months
The anti-B cell malignancy effect of P-CD19CD20-ALLO1 (ORR)
Overall Response Rate (ORR) - Percentage of patients with complete response (CR) or partial response (PR)
Time frame: Baseline through 15 years
The anti-B cell malignancy effect of P-CD19CD20-ALLO1 (DOR)
Duration of Response - Time from complete response (CR) or partial response (PR) to progressive disease
Time frame: Baseline through 15 years
The anti-B cell malignancy effect of P-CD19CD20-ALLO1 (PFS)
Progression Free Survival (PFS) - Time from P-CD19CD20-ALLO1 treatment to progressive disease
Time frame: Baseline through 15 years
The anti-B cell malignancy effect of P-CD19CD20-ALLO1 (OS)
Overall Survival (OS) - Duration of survival from time of treatment with P-CD19CD20-ALLO1
Time frame: Baseline through 15 years
The effect of cell dose and LD regimen to guide selection of specific cell dose and LD regimen for further assessment in Phase 2/3 studies
Cytokine release syndrome (CRS) graded using American Society for Transplantation and Cellular Therapy (ASTCT) criteria
Time frame: Baseline through 36 months
This study is active, not recruiting, as verified in May 2026. You cannot join it, but the record below documents what was studied.
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Lymphoma, Large B-Cell, Diffuse→
Poseida Therapeutics, Inc.