Ziopharm Oncology Shares Trade Up After Hours After 8-K Shows CD19-specific CAR T-cell therapy Update

ZIOPHARM Oncology, Inc.

, a biopharmaceutical company focused on new cancer immunotherapies, today announced that results from its CD19-specific CAR T-cell therapy programs were presented at the 57th American Society of Hematology (ASH) Annual Meeting in Orlando, Florida. The presentation (Abstract 862), titled "Pre-Emptive Donor Lymphocyte Infusion with CD19-Directed, CAR-Modified T Cells Infused after Allogeneic Hematopoietic Cell Transplantation for Patients with Advanced CD19+ Malignancies" was presented by lead author Partow Kebriaei, M.D., Associate Professor, Department of Stem Cell Transplantation and Cellular Therapy, Division of Cancer Medicine, The University of Texas MD Anderson Cancer Center, in an oral session, and is available at www.ziopharm.com. The investigational therapies infusing T cells genetically modified to express a CD19-specific chimeric antigen receptor (CAR), described in the presentation, were exclusively licensed to ZIOPHARM and its collaboration partner, Intrexon Corporation

, through an agreement with MD Anderson. "This study, which was initially designed to test the safety and tolerability of the Sleeping Beauty platform, a system for the non-viral genetic modification of cells, appears to show a survival benefit with a doubling of overall survival compared to historical controls," said Dr. Richard Champlin, Chair, Department of Stem Cell Transplantation and Cellular Therapy at MD Anderson. "This is the measure of clinical success for a post-transplant therapy, where the contribution of either treatment is difficult to discern in early follow-up. Also promising was the absence of GvHD among HLA-mismatched CAR+ T-cell recipients, even at large doses, which supports infusing third-party T cells." In the two separate trials described in Dr. Kebriaei's presentation, patient-derived (autologous) or donor-derived (allogeneic) CAR-modified T cells targeting CD19 were administered to recipients with advanced CD19+ malignancies after hematopoietic stem-cell transplantation (HSCT). The studies employed the Sleeping Beauty system, a cost-effective non-viral two plasmid electroporation method to stably express CAR in T cells. -------------------------------------------------------------------------------- Seven patients with advanced non-Hodgkin lymphoma (NHL) were treated with autologous cells, all of whom remained alive and six of whom remained in complete remission at a median 25.5 months of follow-up translating to a three-year progression free survival (PFS) of 83% and a three-year overall survival (OS) of 100%. Nineteen patients with advanced acute lymphoblastic leukemia and NHL were treated with allogeneic T cells. One-year PFS among these patients was 53% and one-year OS was 63%. Among eight patients who received donor-derived T cells after haploidentical HSCT, all remained alive and six remained in complete remission after a median of 5.2 months of follow up, translating to a one-year PFS of 75% and OS of 100%. No infusion related or late toxicity was observed in any recipients. A mild elevation in cytokines was observed, without cytokine storm. Autologous and allogeneic cells survived an average of 201 and 51 days, respectively. A graft-versus-host disease (GvHD) rate of 11% was observed among recipients receiving donor-derived CAR+ T cells which did not differ from controls. Because of this low rate of GvHD, a complication associated with allogeneic HSCT, administration of up to 108/m2 genetically modified haploidentical T cells was possible. This lays the groundwork for infusing HLA-mismatched CAR+ T cells as an off-the-shelf broadly-accessible therapeutic. "Sleeping Beauty, which is among the fastest technologies to go from bench to bedside, was a critical innovation of this trial," said Laurence Cooper, M.D., Ph.D., Chief Executive Officer of ZIOPHARM. "In addition to demonstrating safety and durable responses, it provides us a pathway for testing new CARs, co-expressing CAR with other molecules, and to do so at relatively low cost in the setting of both patient-derived and third-party derived products. We look forward to the new trial initiated at MD Anderson using Sleeping Beauty-modified T cells expressing a next-generation CD19-specific CAR in active CD19+ lymphoid malignancies." Results from the haploidentical population were also presented separately in an oral presentation, titled "Donor-derived CD19-specific CAR+ T-cell therapy after haploidentical hematopoietic stem-cell transplantation," by Dr. Cooper, at the Haplo2015 Symposium, December 3, 2015, in Orlando, Florida. The presentation is available at www.ziopharm.com.