KTE-C19 feasible in most young, high-risk ALL patients, study suggests

Of the 28 patients who achieved MRD-negative CR, 21 went on to HSCT after KTE-C19. The median time to HSCT after CAR T-cell dose was 54 days. (Ten of the 28 patients had HSCT before receiving KTE-C19.)

Nineteen (91%) of the patients who proceeded to HSCT after KTE-C19 did not relapse, compared to 1 (14%) of the patients who did not have a post-CAR T transplant.

The median LFS was 4.9 months among the MRD responders who did not proceed to HSCT and undefined among MRD responders with a transplant after KTE-C19.

The probability of survival was 65% beginning at 18 months among patients who underwent HSCT and 14% beginning at 9.8 months among patients without a post-KTE-C19 transplant.

CD19 escape remains a challenge, Dr Lee said. The risk may be diminished, but not eradicated, with HSCT.

Toxicity

“There was a low rate of CRS, which was successfully managed with a grade-driven algorithm,” Dr Lee noted.

Five patients (10%) had grade 3 CRS, and 2 (4%) had grade 4 CRS.

Other grade 3/4 adverse events that were considered at least possibly related to therapy included fever (38% grade 3), febrile neutropenia (23% grade

3), hypotension (9% grade 3, 4% grade 4), LV systolic dysfunction (9% grade 3), prolonged QTc (2% grade 3), dysphasia (2% grade 3), cardiac arrest (2% grade 4), multi-organ failure (2% grade 3), hypoxia (2% grade 3, 2% grade 4), and pulmonary embolism (2% grade 3).

“There were no severe or permanent neurologic toxicities,” Dr Lee said. “Intensive neuropsychological testing in 13 patients revealed no consistent treatment-related neurocognitive decline, and several patients improved following therapy.”

In all, there were 46 cases of neurotoxicity, including visual hallucination (8 grade 1, 17%), headache (1 grade 3 [2%], 3 grade 2 [6%]), confusion (2 grade 1, 4%),

dysphasia (1 grade 3, 2%), delirium (1 grade 3, 2%), seizure (1 grade 2, 1 grade 1 [2% each]), ataxia (1 grade 2, 2%), tremor (1 grade 2, 2%), dysesthesia (1 grade 2, 2%), and dysarthria (1 grade 1, 2%).