Dive Brief:

• A cancer cell therapy developed by Arcellx and Gilead Sciences helped reduce or eliminate signs of multiple myeloma in 95% of people in advanced stages of disease, the companies said Monday. The data, from trial volunteers whose cancer progressed after prior treatment, compared well to the leading multiple myeloma cell therapy, Johnson & Johnson and Legend Biotech’s Carvykti.
• None of the trial volunteers taking the Arcellx cell therapy have so far experienced movement disorders caused by nerve damage, a side effect that has worried doctors treating multiple myeloma. A safer cell therapy that’s just as effective as Carvykti could be more attractive to patients and physicians, according to analysts.
• The data came in an abstract of a presentation that’s scheduled to be presented at the American Society of Hematology’s annual meeting in December. The companies also have released data from a small Phase 1 test of the cell therapy in people with multiple myeloma in earlier stages.

Dive Insight:

Carvykti followed Bristol Myers Squibb and 2Seventy bio’s Abecma onto the market. Like Abecma, it is a CAR-T therapy targeted to a protein called BCMA that’s commonly found on diseased multiple myeloma cells. Carvykti has established itself as the leading option, having now gained regulatory approval for use after just one line of therapy, compared to two for Abecma.

All of these CAR-Ts are engineered from patients’ own immune cells and designed to detect and attack diseased cells expressing BCMA. They are complex to manufacture and come with challenges for patients, including preparatory treatment as well as immune-related side effects. In many cases, people who receive them must stay in or near a specialized medical facility for a period of time.

One side effect is a movement disorder known as parkinsonism, which developed in eight of the 285 trial volunteers who received Carvykti in its key clinical trials. Physicians are therefore looking to newer, experimental drugs in hopes they might come with lower risk of that side effect.

Arcellx and Gilead presented data from two trials of their drug, called anitocabtagene autoleucel or anito-cel. They included a Phase 2 study that the companies hope supports regulatory approval in people whose multiple myeloma has progressed following four lines of therapy, and a Phase 1 study in people who have received one to three lines of therapy.

In both studies, investigators saw no cases of parkinsonism or other related nervous system side effects.

In the Phase 2 study, diseased cells declined or disappeared altogether in 95% of trial volunteers who received anito-cel. Three-fifths experienced a complete or near-complete elimination of cancerous cells. In roughly the same population, Carvykti led to an overall response rate of 98% and a complete response rate of 80%, although a direct comparison can’t be made because the two haven’t been tested head-to-head.

Wall Street analysts had different opinions of the data. To Stifel analyst Benjamin Burnett, who covers Arcellx, anito-cel “checks the box” on showing similar efficacy and better side effect profile. One participant died after a hemorrhage, however, which he noted as a potential cause for concern.

RBC Capital Markets analyst Leonid Timashev, who covers J&J partner Legend, focused on anito-cel’s efficacy data. “Our sense from the totality of the efficacy data is that Carvykti remains the most effective BCMA cell-therapy, and with our work suggesting that efficacy is the most important factor for physicians, we believe Carvykti will likely retain its place as the preferred CAR-T,” he wrote.

Arcellx shares fell 6% Tuesday morning, while Gilead’s traded flat.