FDA places clinical hold on Unum’s cell therapy trialPublished: July 4, 2019
The U.S Food and Drug Administration (FDA) has placed clinical hold on Unum Therapeu-tics’ cell therapy trial a second time after a patient experienced serious adverse events including neurotoxicity and respiratory distress.
The Phase 1 trial (ATTCK-20-2) is evaluating an engineered cell therapy, ACTR087 in com-bination with rituximab in patients with relapsed/refractory CD20+ B cell non-Hodgkin lymphoma (r/r NHL).
ACTR087 is an autologous T cell therapy designed to bind to cancer cells and then orches-trate their destruction via mechanisms including the release of cytokines and recruitment of immune-mediated killer cells.
The clinical hold was initiated after Unum submitted a safety report to FDA about a pa-tient in its safety expansion cohort of the trial who recently experienced serious adverse events that included Grade 3 neurotoxicity and cytomegalovirus infection, and Grade 4 respiratory distress.
This is the second time Unum is halting the trial because of safety issues. Earlier, one pa-tient had died after suffering neurotoxicity related to ACTR087 and two other patients suffered cytokine release syndrome. The trial was later restarted after the FDA accepted the protocol and dosing amendments.
Patients receiving the combination therapy receive doses of lymphodepleting chemo-therapy with fludarabine and cyclophosphamide beforehand to make the tumor more vulnerable to the treatment.
Unum Therapeutics uses T cell technology to develop cellular immunotherapies for treat-ing cancers. ACTR087 is no longer Unum’s lead product candidate as it had announced last year that it was deprioritizing ACTR087 in order to advance its new ACTR construct, ACTR707. Unum had stopped enrolling patients in the Phase 1 ATTCK-20-2 trial with ACTR087 earlier this year.
FDA has agreed that patients who previously received ACTR087 and have ongoing clinical responses may continue to receive rituximab infusions, with continued monitoring for adverse events. Unum will continue to work closely with the FDA to further review these events.
Unum has four ongoing clinical programs currently in Phase 1 clinical testing, including ACTR707 used in combination with rituximab in adult patients with r/r NHL; ACTR087 used in combination with Seattle Genetics’ novel antibody SEA-BCMA in r/r multiple mye-loma; and ACTR707 used in combination with trastuzumab in adult patients with HER2+ advanced cancer.
Unum share fell by nearly 20% in after-hours trading following the news. While ACTR087 is no longer Unum’s lead lymphoma drug, the safety of the asset could still have implica-tions for the company and the adverse events could widely impact the technology, draw-ing more scrutiny to the effects of engineered human immune cells.
Source: FDA puts Unum T cell therapy trial on hold after adverse events; Website