Immpact Bio cleared to start clinical trial of IMPT-514 in SLE patients
Phase 1b/2 trial to test CAR-T cell therapy for treatment-resistant SLE
The clearance by the U.S. Food and Drug Administration “marks a pivotal milestone for our autoimmune disease clinical program,” Sumant Ramachandra, MD, PhD, company president and CEO, said in a press release.
Immpact plans to launch an open-label Phase 1b/2 clinical trial that will test IMPT-514 in people with SLE who have received at least two prior standard-of-care therapies, but still have substantial symptoms, as evidenced by a score of eight or higher on the SLE Disease Activity Index score.
Phase 1 of trial to enroll people with active lupus nephritis
The Phase 1 portion of the trial, which will evaluate multiple increasing doses of IMPT-514, will enroll people with active lupus nephritis, a serious complication of SLE characterized by kidney inflammation and damage. The Phase 2 part of the trial will enroll additional patients, with and without active lupus nephritis.
Lupus is caused by the immune system mistakenly attacking the body’s own healthy tissues. B-cells, the immune cells mainly responsible for producing antibodies, play a central role in the autoimmune attack that drives the disease.
IMPT-514 is a CAR-T cell therapy that is designed to reduce lupus activity by destroying B-cells.
T-cells are another type of immune cell that are capable of killing other cells. In CAR-T cell therapy, T-cells from a patient are collected and equipped with a chimeric antigen receptor, or CAR, which is a specialized protein receptor that directs T-cells to attack and kill other cells harboring specific molecular targets.
For IMPT-514, T-cells are equipped with a CAR that simultaneously directs them to attack cells containing two proteins, called CD19 and CD20, which are typically found in B-cells. Immpact is developing a therapy using the same CAR, called IMPT-314, to treat certain types of cancer that are caused by the uncontrolled growth of B-cells.
IMPT-514 is “the first bispecific CD19/CD20 CAR T therapy being investigated for the treatment of systemic lupus erythematosus,” Ramachandra said.
Potential to reset immune response for durable remission
“The differentiated bispecific approach of IMPT-514 is designed for broader targeting of autoreactive B cells with the enhanced tissue and lymphoid organ penetration characteristic of CAR T cells,” he added. “This offers the potential for a one-time treatment administration capable of resetting the immune response for durable remission.”
In a prior Phase 1 study, IMPT-514 showed a promising safety profile. It did not cause any neurological problems, or lead to any serious instances of cytokine release syndrome, an inflammatory side effect of CAR-T cell therapy that can occur due to excessive levels of inflammatory signaling molecules called cytokines in the body.
“The robust data package for IMPT-514 includes compelling Phase 1 safety data from an ongoing investigator-led study in lymphoma at UCLA [University of California, Los Angeles] demonstrating no neurotoxicity and only Grade 1 [mild] cytokine release syndrome to date,” Ramachandra said. “We have also successfully manufactured active product with cells derived from heavily treated patients with autoimmune diseases and are encouraged with the potent autologous B-cell killing properties and limited cytokine production displayed by IMPT-514 in vitro [in lab-cultured cells].”