First graft of a patient's own iPSC neurons

The research record

This is the project's file for this landmark, as written and checked. Sources are listed at the end; anything not yet confirmed is marked "Not yet verified".

Who

Jeffrey Schweitzer (neurosurgeon, Massachusetts General Hospital, lead author), Kwang-Soo Kim (McLean Hospital, senior author), Bob Carter and Todd Herrington (MGH), with Michael Kaplitt (Weill Cornell) on surgery.

What happened

Skin cells from a man with a 10-year history of Parkinson's were reprogrammed into induced pluripotent stem cells (landmark 32) and made into dopamine-neuron precursors under clinical-grade (GMP) conditions. In mouse tests with human immune cells they showed no sign of immune attack. Under an FDA individual-patient expanded-access permission, 4 million cells were placed in the putamen at each of two operations, left side first and right side six months later. Reported in the New England Journal of Medicine (print issue 14 May 2020). The patient took no immunosuppressants.

At 24 months, F-DOPA PET (a scan of dopamine-making capacity) showed modest uptake increases, mainly in the back of the putamen (changes of -4.0% to +13.5% on the right and -4.8% to +9.8% on the left, which the authors call modest). Daily "off" time fell from 3 hours to under 1. Levodopa-equivalent dose fell 6% (904 to 847 mg a day). The motor exam off medication (MDS-UPDRS Part III) was 33 at 24 months, against 43 four weeks after the first implant. The abstract says symptoms stabilised or improved at 18 to 24 months.

Why it moved us toward a cure

It was the first demonstration that a patient's own cells could be made, checked and grafted, avoiding the lifelong immunosuppression that donor-cell grafts need (landmark 10). It followed the monkey work in landmark 30.

Outcome

Open. It is one open-label case with no control group. The idea is now being tested in multi-patient trials (landmark 76).

Sources

• Schweitzer et al., N Engl J Med 2020;382(20):1926–1932, DOI 10.1056/NEJMoa1915872, PMID 32402162 (PMC7288982, read 19 Oct 2026; record)
• Harvard Brain Initiative summary
• AJMC report · BioSpace report
• Not yet verified: the online-first date (PMC gives the 14 May 2020 issue date only); the surgery years (earlier text said 2017 and 2018, which the paper does not state); whether symptom gains persisted beyond 24 months; the safety record (tumours, adverse events), which the abstract does not cover.