Nkarta stock soars 112% after FDA clears cell therapy to go beyond cancer into lupus

Nkarta wants cell therapy to go beyond cancer and has been given the FDA green light to move forward with a CAR NK candidate in human trials for lupus—news that sent the company’s stock soaring 112%.

Nkarta CEO Paul Hastings' headshot
CEO Paul Hastings (Nkarta)

“Autoimmune patients have limited options these days, and those options that they have are often toxic, or hard to take—hard to live with,” Nkarta President and CEO Paul Hastings told Fierce Biotech in an interview. “What we're hoping to do is to move that patient population into an easier to take, patient-friendly therapy.”

After Nkarta said Oct. 17 that the FDA is allowing a human test of NKX019 in lupus nephritis, the company’s stock rose from $1.47 per share at market open to $3.14 by the end of the day. The allogeneic, CD19-directed CAR NK cell therapy candidate is already being tested out in a phase 1 trial for patients with B-cell malignancies, with top-line data expected next year.

In the shadows of Nkarta’s big announcement lies a workforce reduction, with the company set to lay off 18 employees, according to Securities and Exchange Commission documents filed Oct. 16.

The cuts—which will take place “across the board,” according to Hastings—align with the company’s mission to focus on its later-stage programs, including NKX019.

The layoffs are an attempt to save cash and support operations through 2024, when Nkarta anticipates multiple clinical data readouts. Alongside other cost-cutting measures, the layoffs are expected to extend the company’s cash runway by a year into 2026. 

As of Sept. 30, the biotech had $278.4 million on hand.

Lupus nephritis impacts the kidneys specifically and is one of the most severe forms of systemic lupus erythematosus (SLE), an autoimmune disease in which the immune system attacks its own tissues, causing widespread inflammation and tissue damage.

“We're actively looking at other autoimmune diseases,” Nkarta Chief Medical Officer David Shook, M.D., told Fierce. “There's lots of diseases that are caused by autoantibodies, not just lupus. And we think that targeting B cells could be helpful in those as well.”

Nkarta CMO David Shook
CMO David Shook, M.D. (Nkarta)

Their theory is supported by a German study among five patients with SLE who received CAR-T cells, Shook said. The study, published last year in Nature Medicine, found all five patients were in remission after three months and that remission was maintained even after the reappearance of B cells beyond three months. 

Nkarta's new trial will be a multicenter, open-label, dose-escalation study in patients with refractory lupus nephritis. Patients will receive a three-dose cycle of NKX019 on three separate occasions, each a week apart, after lymphodepletion with cyclophosphamide, an immunosuppressive drug with an established safety profile in lupus that is also used as chemotherapy. The trial is expected to include up to 12 patients, with the first patient set to enroll in the first half of 2024.

Nkarta is also partnering with Lupus Therapeutics, a clinical research affiliate of the Lupus Research Alliance, to help speed up NKX019’s development.

Current lupus treatments include GSK’s SLE drug Benlysta, a biologic therapy approved by the FDA in 2011 that brought in more than $1 billion last year, and AstraZeneca’s Saphnelo, an IV infusion that snagged approval for patients with SLE in 2021.   

“Right now, what's on the market are largely ineffective and require, more or less, lifetime treatment,” Shook said. 

Bringing cell therapy outside of cancer may be seen as somewhat inaccessible right now, Shook said, adding that there’s “lots of legwork.” However, if NKX019 were to reach the market, Nkarta expects its off-the-shelf availability to reduce patient burden and eliminate the need for costly infrastructure and treatment delays currently associated with autologous cell therapies. The asset is active immediately, is self-sustaining and doesn’t require large cytokine surges from preparative chemotherapy.