Artiva Biotherapeutics will lay off most of its staff and stop developing an experimental “natural killer” cell therapy for autoimmune conditions after reporting the deaths of two participants in a clinical trial.
Artiva made clear in a Tuesday statement that both of the deaths appear unrelated to its therapy, which is known as AlloNK and was being tested in inflammatory diseases like rheumatoid arthritis. One participant developed leukoencephalopathy — a potentially deadly neurological reaction — that a study investigator linked to a chemotherapy, fludarabine, used to prepare patients for treatment.
The other patient “experienced sudden death” roughly two months after starting treatment and, while the cause hasn’t been determined, a trial researcher again concluded that neither AlloNK nor “any other component” of the treatment regimen was to blame.
Artiva reported the first event to the Food and Drug Administration, which then asked Artiva to pause its ongoing Phase 2a trial. The biotech stopped planned enrollment and dosing in a Phase 3 trial, too.
AlloNK didn’t appear as long-lasting as the company had hoped, either. The effects seen in testing “did not reflect the level of durability of clinical response the company believes is needed to support continued development,” according to the Tuesday announcement.
Artiva now plans to lay off 94% of its staff and has hired a financial adviser to begin a strategic review — a process that often ends in a reverse merger or asset sale. As of the end of September, Artiva held $319.1 million in cash and cash equivalents, according to a federal securities filing.
Artiva is one of many companies that had been pursuing cell therapies relying on “natural killer,” or “NK” cells. These cells have different characteristics than the T cells used in CAR-T therapies for cancer and have been seen as potentially more convenient, “off-the-shelf” alternatives. Artiva’s treatments, for instance, were derived from donor cells rather than cells collected from individual patients.
Like many others working on these therapies, though, Artiva has changed course. The company canceled plans for an initial public offering in 2022 before pivoting to autoimmune conditions and eventually joining the public markets two years later.
The company had been running a mid-stage “basket” trial in multiple inflammatory diseases, among them systemic sclerosis and myositis. Artiva disclosed some study results earlier this year, and planned to report additional findings at a medical meeting this month.
Those presentations have now been canceled, along with a planned Nov. 9 investor call, Artiva said. Artiva also plans to share findings from the fludarabine-associated death in a scientific publication given the treatment’s “widespread use in cell therapy conditioning regimens,” said CEO Fred Aslan, in a statement.
Artiva could sell or license its technology or merge with another company given its “sizable” cash balance, wrote TD Cowen analyst Tyler Van Buren. But “regardless of the outcome, we do not expect meaningful appreciation” in share value, he added.
The news represents the latest setback for a company pursuing cell therapy for autoimmune disease. In August, Novartis and Bristol Myers Squibb paused multiple trials of their cellular medicines rap-cel and zola-cel due to safety concerns. Novartis reported three deaths from a serious immune reaction, while Bristol Myers disclosed “transient and reversible inflammatory events.”
Last week, Bristol Myers Squibb revealed that a patient had died 44 days after receiving a dose of zola-cel.
Unlike Artiva’s AlloNK, Bristol Myers and Novartis’ treatments are “autologous” therapies harvested from a patient’s body, re-engineered and reinfused. Those therapies were also made with the help of a speedy manufacturing process Wall Street analysts have flagged as a possible culprit.