# FELIX

Source: https://onco.cc/trials/felix/  
OnCo record `felix` (Trial). Data CC BY-NC 4.0, attribute "Data from OnCo (onco.cc)"; commercial use needs a licence.

## TL;DR

The trial that showed a gentler CAR-T design could treat adult ALL with a fraction of the severe side effects.

## Summary

FELIX, trial NCT04404660 sponsored by Autolus and published in the New England Journal of Medicine in 2024, showed that a gentler CAR-T design, obecabtagene autoleucel, could treat adult relapsed or refractory B-cell acute lymphoblastic leukaemia with a fraction of the severe side effects of earlier products. Of 153 enrolled, 127 were infused; the overall remission rate was 77 percent with complete remission in 55 percent, severe cytokine release syndrome occurred in under three percent, and about forty percent were event-free at two years, most without transplant, leading to FDA approval on 8 November 2024 without a REMS programme. OnCo links it to acute lymphoblastic leukaemia, CAR-T, CD19 as a target and obecabtagene autoleucel, and the UCL predecessor ALLCAR19 showed the same profile. Whether the fast-off-rate design generalises to other CAR-T targets is the open question.

## Fields

- Kind: Trial
- Status: positive
- Last checked: 2026-09-07
- Registry id: NCT04404660
- Phase: 1/2
- Setting: Relapsed or refractory B-ALL, adults: obecabtagene autoleucel single split-dose course
- Sponsor: Autolus
- Enrolled: 153
- Result: ORR 77%, CR 55%; grade ≥3 CRS 2.4%.
- Outcomes: Overall remission (CR + CRi): Obe-cel 77%; Complete remission: Obe-cel 55%; Event-free survival (median): Obe-cel 11.9 months
- Replication: ALLCAR19 (the UCL phase 1 predecessor) showed the same low-toxicity, high-remission profile.

## Sources

- ClinicalTrials.gov NCT04404660: https://clinicaltrials.gov/study/NCT04404660

## Connected records

- cancers: [Acute lymphoblastic leukaemia](https://onco.cc/cancers/all-leukemia/), [Relapsed and refractory acute lymphoblastic leukaemia in children](https://onco.cc/cancers/all-paediatric-relapsed/)
- technologies: [CAR-T cell therapy](https://onco.cc/technologies/car-t/)
- targets: [CD19](https://onco.cc/targets/cd19/)
- drugs: [Obecabtagene autoleucel](https://onco.cc/drugs/obecabtagene-autoleucel/)
- companies: [Autolus Therapeutics](https://onco.cc/companies/autolus/)

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JSON: https://onco.cc/api/v1/entities/felix.json