Kite climbs after PhII data tee up FDA filing for CAR-T

Kite Pharma ($KITE) has posted an interim analysis of Phase II CAR-T data it thinks are strong enough to support regulatory approval. The CAR-T triggered complete remissions in 47% of patients with an aggressive form of non-Hodgkin lymphoma (NHL), although a dropoff in the number of responders over the first three months has raised questions about durability.

At the time of the interim analysis, Kite had administered its CD19-targeting CAR-T to 51 patients with chemorefractory diffuse large B-cell lymphoma (DLBCL). More than three quarters of patients experienced an objective response. Close to half experienced complete remission. When paired to stronger data from a small group of patients with transformed follicular lymphoma (TFL) and primary mediastinal B-cell lymphoma (PMBCL), Kite thinks the interim analysis boosts its prospects.

“We are extremely encouraged by the result of this analysis,” Kite CEO Arie Belldegrun told investors on a conference call to discuss the data. “These are remarkable results for a patient population that has historically had very poor outcomes.”

Kite is hoping the level of unmet medical need of patients with aggressive non-Hodgkin lymphomas will ease the regulatory path of KTE-C19, enabling it to drive home its recently-extended lead over Juno Therapeutics ($JUNO) in the CAR-T race. How big a head start Kite gets will depend on whether FDA shares the company’s view that data from the interim, three-month analysis of the clinical trial are strong enough to support the approval of KTE-C19.

Belldegrun’s long-held objective is to file for approval by the end of the year, positioning KTE-C19 to come to market in 2017. Yet Kite CMO David Chang, while talking up the risk-benefit profile of the Phase II data, skirted round analyst questions about whether Kite will file for approval by the end of the year.

“[FDA] will have to look at the available dataset, which they have not, before giving us any further indication,” he said. “We plan to meet with FDA to discuss the full extent of the interim analysis, based on which we will finalize the details of our BLA plan.”

Potential barriers to Kite’s quicke-filing plan include questions about the safety and durability of its CAR-T. Across the combined dataset of 62 patients, two participants died of KTE-C19-related adverse events. Two-thirds of patients experienced grade three or higher neutropenia. And cytokine release syndrome affected 18% of subjects.

Given the condition of patients going into the trial, their prospects without KTE-C19, the side effect profile of alternative treatments and the potential for doctors to get better at spotting and mitigating CAR-T adverse events, Kite thinks the adverse event data aren’t an impediment for the program.

Kite is similarly confident the dropoff in responses over the first three months of the study won’t scuttle KTE-C19. While 47% of patients in the DLBCL cohort experienced an initial complete response, the figure fell to 33% after three months. A similar decline after six and nine months would be a blow to the long-term efficacy of KTE-C19, but Phase I data give Kite reason to believe the figure will level off.

“Patients who maintain CR at month three, they tend to be maintained in complete remission,” Chang said.

Shares in Kite rose 10% in after-hours trading.