Optimization and Validation of a Harmonized Protocol for Generating Therapeutic-Grade Dendritic Cells in a Randomized...

Area of Science:

• Immunotherapy
• Cell-based therapy
• Good Manufacturing Practice (GMP)

Background:

• Autologous dendritic cell (DC)-based immunotherapy, an advanced therapy medicinal product (ATMP), has been available for over 30 years.
• Generating clinical-grade DCs requires specialized facilities and adherence to strict manufacturing standards.

Purpose of the Study:

• To establish a harmonized, GMP-compliant manual protocol for generating clinical-grade DCs.
• To assess the feasibility of this protocol in a limited-resource academic setting.
• To evaluate the quality, consistency, and long-term stability of cryopreserved DCs.

Main Methods:

• Leukapheresis was performed on patients following ethical approval and informed consent.
• A manual, GMP-compliant method was used for single-batch DC production.
• Responder-independent flow cytometric assays were employed for quality control, defining differentiation and maturation indices (DI and MI).
• Cryopreservation stability and personnel variation were assessed over 2-3 years.

Main Results:

• The harmonized protocol yielded an average DI of 1.39 and MI of 1.25.
• Allogeneic responder proliferation was observed in all patients.
• IFN-gamma secretion correlated significantly with CD8+ T cell proliferation (p=0.0002).
• Cryopreserved DCs maintained >90% viability for up to 3 years and mature phenotype for 1 year.

Conclusions:

• The manual/semi-automated protocol is simple, consistent, and cost-effective for producing high-quality clinical-grade DCs.
• This approach is suitable for limited-resource academic settings, requiring no expensive equipment.
• The protocol ensures the quality and stability of DCs for advanced cell-based immunotherapy.