A Cancer Trial, and the Limits of a Five-Day Headline
Updated: Sep 6
Correction — 6 September 2026
An earlier version of this article overstated an experimental cancer treatment and did not identify its source. It omitted recurrence and side effects. Claims that the treatment destroyed only malignant tissue, activated a tumour self-destruct sequence and promised recovery in days were not substantiated and have been removed.
A primary report matching the five-day account appeared in the New England Journal of Medicine in March 2024. It described three participants with recurrent glioblastoma in an early phase 1 trial at Massachusetts General Hospital.
The treatment, CARv3-TEAM-E, used engineered T cells delivered through a catheter into a brain ventricle. This was a specialised cell-therapy procedure.
One woman's MRI showed near-complete tumour regression five days after treatment. Evidence of recurrence appeared within a month. Responses were transient in two of the three participants. All three developed fevers; grade 3 encephalopathy and fatigue were also reported as probably related to treatment.
Those results warranted further investigation. They did not establish a one-shot cure, a treatment without side effects, or an outcome that could be expected across cancers.
A scan can show an encouraging change without telling us how long it will last. Hope deserves the whole account: the treatment, the size of the study, the follow-up and the limits.
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