-Author name in bold denotes the presenting author
-Asterisk * with author name denotes a Non-ASH member
Clinically Relevant Abstract denotes an abstract that is clinically relevant.

PhD Trainee denotes that this is a recommended PHD Trainee Session.

Ticketed Session denotes that this is a ticketed session.

2045 High-Density Cryopreservation of Off-the-Shelf CAR-NK Cells Facilitates On-demand Treatment Access

Program: Oral and Poster Abstracts
Session: 711. Cell Collection and Processing: Poster I
Hematology Disease Topics & Pathways:
Fundamental Science, Biological therapies, cell expansion, Therapies, Immunotherapy, Natural Killer (NK) Cell Therapies, Technology and Procedures
Saturday, December 10, 2022, 5:30 PM-7:30 PM

Ya-Ju Chang, PhD1*, Niancao Chen, PhD1*, Christine Chen2*, Tingxia Guo, PhD1*, Jaslem Herrera Valdez, BS1*, Svetlana Gaidarova, MS1*, Bryan Hancock, PhD1*, Betsy Rezner, BS1*, Yvonne Lentz, PhD1*, Mark Plavsic, PhD1*, Richard Anderson, PhD1*, Raedun Clarke, PhD3* and Bahram Valamehr1

1Fate Therapeutics, Inc., San Diego, CA
2Fate Therapeutics, San Diego, CA
3Fate Therapeutics Inc., San Diego, CA

Multiplexed engineered, clonal master induced pluripotent stem cell (iPSC) lines are a renewable source for the routine, mass production of immune effector cells that address many shortcomings associated with current autologous and allogenic donor-derived cell-based immunotherapies, including off-the-shelf availability for broad patient access and multi-dose administration. To enable the feasibility of multi-dose administration and dose escalation of iPSC-derived NK (iNK) and T (iT) cells without extending the patient administration time and ensuring continuous drug product (DP) availability at all treatment sites, we evaluated the feasibility and stability of manufacturing high-cell density fill (HD-fill) doses of multiplexed-engineered iNK cells.

To select the ideal cryopreservation formulation in HD-fill studies, we performed iterative formulation screening supported by orthogonal analytical characterizations looking at cell viability, proliferation capacity, and cytotoxicity function upon thaw and over time. The tested HD-fills were produced using two iNK cell products, anti-CD19 CAR (CAR19) iNK cells and anti-MICA/B CAR (CAR-MICA/B) iNK cells, directed to the treatment of either B cell malignancies or solid tumors, respectively. At the final formulation stage, cells were added to various formulations at various densities, cryopreserved in CryoMed™ Controlled-Rate Freezers and stored in vapor-phase liquid nitrogen at <-150°C.

We examined standard dose concentration of 1.5E+07 viable cells/mL and HD-fill dose concentrations up to 1.1E+08 viable cells/mL in the top cryopreservation formulation using assessment parameters such as immediate post-thaw recovery and tolerance of hold-time (in-use stability), transgene expression, and potency. Results demonstrated comparable recovery and viability immediately post thaw (>99.0%) as well as after 90 minutes hold time at room temperature (>95.0%) between standard density and HD-fill densities. Transgene expression was also comparable across all HD-fill densities and no differences in drug product purity were observed (>90% CAR for CAR19 and CAR-MICA/B). In vitro cellular cytotoxicity assays were used to evaluate CAR-mediated target cell clearance and antibody-dependent cell cytotoxicity (ADCC). HD-fill of FT536 showed comparable CAR specific cytotoxicity against CaSki cervical carcinoma cells at E:T ratio of 5:1 and ADCC with cetuximab at E:T ratio of 3:1 in the single round and re-stimulation killing assays. HD-Fill of FT596 also showed similar cytolytic potency against Nalm6 leukemia cells compared to the standard dose. Furthermore, HD-fill storage stability was assessed in both liquid nitrogen (<-150°C) and -80°C freezers, with the latter temperature tested to facilitate DP storage at majority of hospitals. Preliminary data show viability, recovery, and potency are consistent for all control and test configurations, including short-term hold in -80°C freezers, demonstrating the suitability of our fill/finish and cryopreservation formulation platform to support HD-fill dose presentations.

In summary, we demonstrate the successful generation of HD-fill CAR-iNK cells without interfering with drug product integrity, identity, and function. HD-fill for off-the-shelf immunotherapies will enable flexibility to clinicians and patients in the out-patient setting for the treatment of hematologic and solid tumors.

Disclosures: Chang: Fate Therapeutics: Current Employment. Chen: Fate Therapeutics: Current Employment. Chen: Fate Therapeutics: Current Employment. Guo: Fate Therapeutics: Current Employment. Valdez: Fate Therapeutics: Current Employment. Gaidarova: Fate Therapeutics: Current Employment. Hancock: Fate Therapeutics: Current Employment. Rezner: Fate Therapeutics: Current Employment. Lentz: Fate Therapeutics: Current Employment. Plavsic: Fate Therapeutics: Current Employment. Anderson: Fate Therapeutics: Current Employment. Clarke: Fate Therapeutics: Current Employment. Valamehr: Fate Therapeutics: Current Employment.

*signifies non-member of ASH