Autolus Therapeutics plc (AUTL)

[jondoeuk]

A new(ish) paper https://www.nature.com/articles/s41591-019-0549-5

It was an open label, PhI trial, and 17 patients (under the age of 25) with advanced, high-risk CD19+ ALL were enrolled. Fourteen patients received lymphodepletion followed by the infusion of CAR T-cells (the product couldn't be generated for the remaining three).

Thirteen out of 14 patients developed cytokine release syndrome, which was generally mild (nine patients with Gr1, and four with Gr2). No severe (Gr3 or above) CRS was observed. Six had Gr1/2 neurotoxicity and one experienced Gr4 encephalopathy. One developed prolonged neutropenia, multiple infections, and Gr4 encephalopathy, and died from sepsis while in remission. Thirteen out of 14 patients developed prolonged B-cell aplasia.

At 30 days post infusion, 10 achieved a complete response. At 90 days, 12 of 14 had achieved a CR, one was alive with CD19+ disease, and one died due to progression of CD19+ disease. Six who achieved CR ultimately relapsed: 5 with CD19- and 1 with CD19+. In cases of CD19+ relapse/non-responding disease, anti-CAR-specific cytotoxic responses were detected, suggesting endogenous T-cell mediated rejection of CAR T-cells (not good). At a median follow-up of 14 months, 5 out of 14 (36%) patients remained in CR. Overall survival was 84% at 6 months and 63% at 12 months. Event-free survival was 63% and 46% at 6 and 12 months, respectively.

CAR T-cells exhibited mostly naive or central memory phenotypes and had a low level expression of PD-1 and TIM3. CAR T-cells underwent robust expansion in the periphery in 12 out of 14 patients, with a median time to peak expansion of 14 days. At peak expansion, a median of 41% of circulating T-cells were CAR T-cells. CAR T-cells contracted over time, but remained detectable in 11 out of 14 patients at last follow-up (up to 24 months for some patients). The median duration of persistence of CAR T-cells at data cutoff was 215 days. Peak expansion, exposure, persistence, and half-life were all higher than published data for an approved product.