Company: PGEN
Filing Date: 2025-03-19
Form Type: 10-K
Source: 0001356090-25-000007
Chunk: 28

Company: PRECIGEN, INC.
Filing Date: 2025-03-19
Form: 10-K
Item: Item 1
Chunk 28
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 of immune effector cell-associated neurotoxicity syndrome (ICANS) was rare with one Grade 1 event and one Grade 2 event in Cohort 1 and Cohort 2, respectively.

Excellent dose-dependent expansion and persistence of PRGN-3006 in peripheral blood and bone marrow was observed following a single infusion in both the non-lymphodepletion and lymphodepletion cohorts highlighting the ability of UltraCAR-T cells to engraft and survive even in the absence of lymphodepletion. Higher peak expansion (> 10 fold) in peripheral blood was observed in the lymphodepletion cohort compared to non-lymphodepletion cohort at the same dose level.

In the lymphodepletion cohort (Cohort 2), an objective response rate (ORR) of 27% (3 out of 11) was reported for heavily pre-treated r/r AML patients with poor prognosis (median prior treatments: 4; range: 1-9). A disease control rate (DCR) of 45% (5 out of 11) was reported at day 28 for r/r AML patients and 100% of MDS patients, respectively. Additionally, of the 15 evaluable patients in the lymphodepletion cohort (Cohort 2), 60% (9 out of 15) heavily pre-treated patients had a reduction in bone marrow blasts following a single PRGN-3006 infusion, with 4 patients experiencing a substantial decrease to ≤5%.

Analysis of peripheral blood samples post PRGN-3006 infusion showed gene expression changes consistent with improvement in the immune compartment function for anti-tumor effect in responders. There was an increase in cytotoxicity, costimulatory signaling, and lymphoid compartment and decreased apoptosis pathway scores in the lymphodepletion cohort on Days 14 and 28 post PRGN-3006 treatment compared to baseline. Based on the results of correlative studies of the patient samples from the Phase 1/1b study, we have identified clinical biomarkers that correlate to objective responses after PRGN-3006 treatment in r/r AML patients. This advancement may further enable patient stratification and positively impact efficacy.

We have completed enrollment in the Phase 1b dose expansion study. We are preparing for an end of Phase 1b meeting with the FDA to discuss the results and next steps. We plan to focus on strategic partnership opportunities to advance PRGN-3006 UltraCAR-T program in AML. PRGN-3006 has been granted