Production Of Autologous Monocytes Stimulated Ex Vivo With Peg-Interferon Alfa 2b And Interferon Gamma 1b For Intraperitoneal Administration In Phase I Clinical Trial.

5 Background: Monocytes are myeloid cells that reside in the blood and bone marrow and respond to inflammation. At the site of inflammation, monocytes express cytokines and chemokines. Monocytes are cytotoxic to tumor cells in the presence of pro-inflammatory cytokines such as Interferon Alpha and Interferon Gamma. We previously showed that monocytes stimulated with both interferons (IFNs) result in synergistic killing of ovarian cancer cells. We aimed to develop this cell therapy product for clinical application. Methods: Counter flow elutriation was performed on healthy donors. The monocyte-containing, RO-fraction was assessed for total monocyte number, purity, viability, and cytotoxicity with and without cryopreservation. All 5 fractions from the elutriation procedure were also assessed by flow cytometry to measure the percent of immune cell subsets. This procedure is now implemented in a clinical trial where 8 patients completed the apheresis and elutriation process for a total of 13 runs. Results: Iterative monocyte isolation using counter flow elutriation with or without cryopreservation can yield over 2 billion monocytes for each subject with high purity. We show that monocytes are stable, viable, and retain cytotoxic functions when cultured with IFNs. Flow cytometric analysis shows expected heterogeneity in the collected monocytes. In each case, the elutriation run met pre-set release criteria for both total monocyte number and purity requirements for the therapeutic product. Conclusions: We demonstrated that large scale isolation of monocytes can be achieved with elutriation from either healthy donors or patients with advanced, chemotherapy resistant ovarian cancer. Monocytes can be cryopreserved and maintain viability and cytotoxic function in the final cell therapy product prior to infusion. We translated these observations to a currently accruing clinical trial using adoptive cell transfer of autologous monocytes stimulated ex-vivo with IFNs and infused into the peritoneal cavity of patients with advanced, chemotherapy resistant, ovarian cancer. (Protocol NCT00327067). Clinical trial information: NCT02948426.