Ziopharm hits pause on planned pivotal brain cancer trial

Ziopharm Oncology has hit pause on a planned pivotal trial of Ad-RTS-hIL-12 in brain cancer patients. Management took the action after technical issues slowed progress of the inducible adenoviral vector.

Boston-based Ziopharm had planned to start testing Ad-RTS-hIL-12 in combination with veledimex in patients with recurrent glioblastoma by the end of last year. Ziopharm pushed back the target to the second half of 2018 when it learned it would take longer than expected to get the asset phase 3 ready. And it has now put the study on hold indefinitely.

Ziopharm is continuing to work to resolve the chemistry, manufacturing and control issue that forced it to delay the trial but it is shifting its clinical development focus to earlier-phase studies. Talking to investors on a quarterly results conference call, Ziopharm chief business officer David Mauney, M.D., sought to frame the action as a positive event.

“This effort greatly expands our addressable markets. It aligns us with what potential partners want to see in terms of clinical data, and have the additional benefit of tremendous cost savings in the near term,” Mauney said. “We view this as a positive pivot point for this platform and executing on this plan will provide the information needed in the shortest time possible and for a fraction of the cost of a randomized controlled pivotal trial.”

With the pivotal trial on the backburner, Ziopharm will focus on expanding its IL-12 program to new indications and combinations. A recurrent glioblastoma trial assessing the human proinflammatory cytokine interleukin-12-encoding vector in combination with Bristol-Myers Squibb’s Opdivo is set to dose its first patient soon. Other IL-12-checkpoint inhibitor cocktail trials are in the works.

Hitting pause on the pivotal trial will give Ziopharm more money for these studies and lessen its financial pressures. Ziopharm closed out the quarter with $51 million in cash, a sum that a late-phase program could wipe out quickly. WIth the phase 3 on hold, Ziopharm now thinks it has enough money to see it through to the second quarter of 2019.