Hematopoietic Cell Preparation for Non-Hematopoietic Purposes: Methods and Results of GMP Validation

Abstract 4446

Hematopoietic stem and progenitor cells are routinely used in onco-hematological applications as consolidated approaches. Recently, these cells have been exploited also for their non-hematopoietic potential in the novel field of regenerative medicine. In fact, several clinical trials are already ongoing in the cardiovascular field, and more and more innovative applications, such as in liver disorders, are emerging to treat patients for whom no other efficient therapies are available.

In Europe, the preparation of hematopoietic cells for non-hematopoietic applications must comply to medicinal products current good manufacturing practices (cGMP) and thus, the production process and the analytical methods applied in quality controls must be validated in order to demonstrate standardization and compliance with pre-defined specifications.

In our hospital-based GMP facility, named Cell Factory, the first one authorized by the National Drug Agency, we have several processes ongoing for different clinical experimental trials. In particular, we produce CD133+ cells from leukapheresis (AF) products for liver chronic disease and bone marrow (BM) CD133+ cells for cardiovascular repair, strictly following the GMP rules governing medicinal product and we validated both processes as herein reported. In our hands, AF and BM need different approaches to improve the purity of the final cell product that is crucially important to have consistent clinical results. In fact, BM requires an efficient erythrocyte depletion that we obtained by optimizing a centrifugation based separation system, before the CliniMacs (Miltenyi, Gladbach, Germany) immunomagnetic purification.

To validate the aseptic technique, three runs of specific media-fill protocols were set up. Finally, to validate the defined protocol, three runs of validation were performed in our class B facility for both procedures with all the quality controls on “in process” as well as on final products.

BM samples from 3 patients who underwent sternotomy for by-pass surgery were collected after informed consent and processed as previously described. The results of the three validation runs were consistent in: cell dose >2×10⁶ (2.54×10⁶, 2.81×10⁶ and 2.62×10⁶), purity >70% (87.5%, 97.4% and 93.6%), viability >70% (88.5%, 90.6% and 96.4%), no growth for sterility and endotoxin <2.5 I.U./mL.

AF samples from 3 patients who underwent mobilized standard-volume leukapheresis were collected and processed. The results of validation processes were consistent in: cell dose >100×10⁶ (181×10⁶, 138.5×10⁶ and 178.3×10⁶), purity >80% (91%, 90% and 92%), viability >80% (89%, 93% and 95%), for sterility no growth and for endotoxin <2.5 I.U./mL.

In conclusion, all the end-points were reached and currently the cell products are provided to different clinical sites as investigational new drug, approved by the national competent authority. These products, as well as other cellular therapy products, are available upon request at our facility for experimental clinical applications (www.cellfactorymilano.com).