Cellectis’ UCART therapy leads to second childhood leukaemia remission

A baby diagnosed with leukaemia at the age of four weeks remains in remission six months after being treated with Cellectis' UCART19 injection.

The infant is the second child to go into remission from treatment with the biotech's Universal Chimeric Antigen Receptor T-cells (UCART) injection, following the case of one-year-old Layla in November last year.

The results were presented at the American Society of Gene & Cell Therapy annual meeting in Washington.

"This is not yet statistical proof but we do now have two cases," said Cellectis chief executive Andre Choulika. "It shows that the therapy has some potential."

The defining feature of Cellectis's UCART19 therapy is its allogeneic nature, which involves the reprogramming of T-cells donated from a healthy individual. In contrast to traditional autologous CAR-T therapies - which rely on the re-programming of T-cells harvested from an affected individual which are then reintroduced into the same patient once modified - using healthy T-cell donations opens the door for potential "off-the-shelf" supplies of the treatment by eliminating the long development process, in turn addressing safety and cost concerns associated with autologous platforms.

Regardless of these concerns, traditional T-cell therapies have been creating plenty of excitement in the past year or so. One study, presented at the American Association for the Advancement of Science's (AAAS) annual meeting in February, claimed a 90% complete remission rate following CAR-T therapy. Results from the study are currently under review.

Although not enough time has passed to consider both babies as cured of their respective diseases, Layla's current state of remission 11 months after treatment for what was deemed an "incurable" leukaemia, and a current remission of six months in this second case is an encouraging sign. The excitement was reflected on the stock market as Cellectis shares jumped 14% following the news.

So far, Cellectis has only been joined in the allogeneic CAR-T field by Celyad which itself has produced an individual take on CAR-T therapy by re-programming natural killer cells specifically.

Clinical trials for UCART19 will start at some point this year.