The Preclinical Service supports the development and implementation of new protocols involving ex vivo expanded adoptive cell therapies through a core staff member working with Cell Processing in the Department of Transfusion Medicine. Our support for new adoptive cell therapies has included scaling up research laboratory products into clinical size expansion cultures using GMP materials and practices, preparing Standard Operating Protocols for generation of cultures, developing release criteria for products and providing documentation of these procedures for clinical IND. Two novel protocols involving donor T cells of defined cytokine phenotype have been implemented this past year as a result of this process. In 04-C-0055 Arm 4A, Daniel Fowler has previously utilized expanded donor-derived CD4 Type 2 T helper cells grown in rapamycin (Th2.Rapa) to enhance donor engraftment and reduce GVHD. The Preclinical Service has supported implementation of a new clinical trial arm (Arm 4B) utilizing a shorter expansion period to generate cells after only 6 days of expansion (Th2.Rapa.6d), to produce a population with increased anti-tumor potency. In protocol 11-C-0016 (P.I. Claude Sportes), patients with multiple myeloma will undergo an autologous transplant followed by infusion of Th1.Rapa cells -- autologous CD4+ T cells that have been expanded to a Th1 cytokine phenotype in the presence of rapamycin. We have also supported the preclinical development of the TDL (tumor infiltrating donor derived lymphocyte) clinical protocol (P.I. Michael Bishop;07-C-0064). Dr. Bishop hypothesized that the donor-derived T cells found in tumor sites after alloHSCT would be enriched for effector cells that were tumor-specific in their homing and antigen specificity. He proposed that activation and ex vivo expansion of these cells through CD3/CD28 costimulation might yield a more effective form of cell therapy after alloHSCT, with enhanced anti-tumor effects and less GVHD. The PCS staff supported this project by assessing the feasibility of expanding TDL in cultures through the use of anti CD3/CD28 beads, generating a donor T cell product with high viability, very low residual B cell content, free of endotoxin or contamination;In this process, we developed methods for viably dissociating cells and culturing them under good manufacturing process (GMP) standards. We further supported the clinical approval process by developing the necessary documentation of standard operating procedures and certificates of analysis for product release, assembling GMP reagents lists, and providing links to established investigational new drug (IND) protocols for manufacture of an clinical product suitable for infusion into patients. We have continued to support a clinical initiative to make this therapy available to a broader patient population. We have successfully expanded replicate cultures from patient marrow collected following allogeneic transplant, demonstrating significant expansion of donor-derived T cells that meet criteria for T cell numbers and viability, donor chimerism, removal of tumor cells and microbial standards;this work supported the amendment permitting expansion of the protocol to generation of TDL from bone marrow. We have also supported the clinical implementation and assessment of this protocol. We have assessed T cell expansion and clearance of B cell lymphoma and Hodgkins disease populations in the lymph node derived TDL expansion cultures in ten patients and in the bone marrow derived TDL from an additional patient. As part of this trial, we are evaluating changes in the peripheral blood following infusion of the TDL product and have been preserving aspirates of tumor sites after TDL therapy to assess molecular changes indicative of donor anti lymphoma activity. We have characterized the TDL product from both preclinical test cultures and from the first clinical trial cultures, using multiparameter flow cytometry and cytokine production assays. We have demonstrated that the TDL expansion cultures in the clinical trial resulted in a marked decline in the frequency of regulatory T cells found in the original tumor population. The final product contained more than 90% T cells, primarily T-Bet+ Th1/Tc1 cells, that had elevated expression of effector molecules including CD40L, NKG2D, and perforin, and produced primarily IFN-gamma on stimulation. These assays have been used to optimize the TDL product in terms of numerical, anti-tumor activity and persistence in vivo after re-infusion. We have shortened the culture period and are examining alterations in the cytokine milieu of the culture to enhance retention of activated CD8 effectors. These flow cytometric and molecular monitoring studies have been extended to the first of additional planned trials of immune therapies for relapse. In this trial (09-C-0224, P.I.: Nancy Hardy) donor lymphocyte infusions (a standard method of immune therapy) are infused following irradiation of selected tumor sites. Monitoring focuses on whether the irradiation and subsequent localized deaths of tumor cells has produced activation and trafficking of antigen presenting cells into the tumor and increased anti-tumor immune activation.
