First serious adverse reaction to iPSC-derived retinal cells reported

Written by Freya Leask

The patient underwent transplant surgery using allogeneic iPSC-derived cells in the trial lead by Masayo Takahashi.

In the world’s first clinical trial utilizing allogeneic iPSC-derived retinal cells to treat age-related macular degeneration, the first serious adverse reaction has been reported. The patient, in his 70s, suffered a swollen retina and was operated on to remove preretinal membrane, determined to be the cause.

“We cannot deny the causal correlation with iPS cells,” commented team lead Masayo Takahashi, Project Leader for Laboratory for Retinal Regeneration at the RIKEN Centre for Developmental Biology (Kobe, Japan), at a news conference, stressing that although it was a serious case that required hospital admission, it was “neither a matter of great urgency nor life-threatening.”

The patient’s original procedure was the second such surgery carried out and Takahashi believes the cause of this event was the technique of transplantation utilized. Therefore, this development did not signify a rejection of the iPSCs but surgery to remove tissue was required after the symptoms could not be improved with the administration of steroid and anti-vascular endothelial growth factor medication.

All five procedures planned in this clinical trial were carried out March—November 2017 and iPSCs kept at Kyoto University (Japan) were specially created to avoid immune reactions. It is hoped that this will not affect future clinical studies utilizing this technique.

“This case is not so serious. As long as the pre-retinal membrane is removed during surgery, there would not be a significant problem,” said Noriyuki Azuma, chief of the visual science laboratory at the National Center for Child Health and Development.

“(This case) would not put a stop to regenerative medical techniques.”

Read an exclusive interview with trial lead Masayo Takahashi carried about before commencement of this clinical trial >> read the interview

Edited 18/01/18: a previous version of this article stated that the team believed the swelling was caused by a reverse in the flow of a liquid solution containing the iPSC-derived retinal cells.