Two of the participants met the definition of partial success at 12 and 18 months, and the overall success of CALEC was 93% at 12 months and 92% at 18 months. Three participants received a second corneal CALEC transplant, of which one experienced complete success by the end check-up visit of the study.
Additional analysis of the impact of CALEC on vision showed varying levels of improvement of visual acuity in all 14 of the participants. The corneal procedure displayed a high safety profile with no adverse events occurring. However, one participant had a bacterial infection eight months after transplant due to chronic contact lens use. Any other adverse events were minor and were resolved quickly.
The CALEC trial is the first human study of a stem cell therapy to be funded by the National Eye Institute (NEI) branch of the NIH. However, the CALEC procedure remains an experimental procedure and it is not offered at Mass Eye and Ear or at any other hospital in America. Mass General Brigham’s Gene and Cell Therapy Institute will be conducting additional randomized-control design studies including a larger number of participants at multiple centers, with longer follow-ups before this treatment will be submitted for federal approval.