Kite Pharma announced that a Phase II study of the experimental CAR T-cell therapy KTE-C19 in patients with chemorefractory diffuse large B-cell lymphoma (DLBCL) met its primary endpoint of objective response rate (ORR), sending the company's shares up as much as 13 percent.
The ZUMA-1 trial enrolled patients with chemorefractory aggressive non-Hodgkin lymphoma (NHL) into two cohorts, with the first cohort including patients with DLBCL and the second cohort comprising patients with transformed follicular lymphoma (TFL) and primary mediastinal B-cell lymphoma (PMBCL). Kite Pharma indicated that it plans to seek approval of KTE-C19 in DLBCL, TFL and PMBCL based upon the combined data of both cohorts.
The company said that top-line results from a pre-planned interim analysis demonstrated that in 51 treated patients with DLBCL, KTE-C19 was associated with an ORR of 76 percent, including 47 percent complete remissions. Further, data showed that after three months of follow-up, the ORR was 39 percent and the complete remission rate was 33 percent. RBC Capital Markets analyst Michael Yee called the complete response rate strong and above expectations. "It is important to note that this [complete remission] rate is very supportive of FDA approval," Yee remarked.
According to Kite Pharma, Grade 3 or higher cytokine release syndrome (CRS) and neurological toxicity was observed in 18 percent and 34 percent of patients in the study, respectively. The company added that two patients in the trial died, with the deaths caused by haemophagocytic lymphohistiocytosis and cardiac arrest in the setting of CRS.
Kite Pharma indicated that additional data from the interim analysis will be submitted for presentation at an upcoming scientific meeting. The drugmaker added that the primary analysis of 101 patients with chemorefractory aggressive NHL will include approximately six months of follow-up and is expected in the first quarter of 2017.
Jeff Wiezorek, senior vice president of clinical development, noted that "ZUMA-1 is the largest CAR-T study reported in NHL," adding "we were able to manufacture KTE-C19 for 99 percent of patients enrolled in the study." KTE-C19 consists of a patient's T-cells engineered to express a chimeric antigen receptor to target the antigen CD19, which is expressed on the cell surface of B-cell lymphomas and leukaemias.