Disappointing results one year into diabetes stem cell trial

Biotech company Osiris Therapeutics has this month released an optimistic update on its Phase II trial evaluating the use of adult stem cells for the treatment of type 1 diabetes, despite lacking positive results.

The treatment, Prochymal, is a formulation of adult mesenchymal stem cells (MSCs), which Osiris hopes could be used in patients with newly diagnosed type 1 diabetes. The trial aims to assess the safety of the treatment and highlight any positive impacts, such as slowing disease progression.

The trial is using MSCs from unrelated adult donors in 63 paediatric and adult patients. The participants were randomly assigned to receive either Prochymal or a placebo, with neither physicians nor patients aware of what group they were in.

According to Osiris, the treatment did not cause any 'adverse events' and 'no patients experienced a reaction to the infusions despite the cells being unrelated to the recipient, unmatched, and used without immunosuppression'.

However, the treatment failed to achieve its primary endpoint: showing no signs of slowing disease progression at the one year time point. The press release reported a 'trend towards fewer hypoglycemic events for patients treated with Prochymal as compared to controls'. Unfortunately for Osiris, this was one of six secondary endpoints, the rest of which failed. The patients will be followed up for one more year.

Osiris has trialled this stem cell preparation against a number of other conditions, including graft-versus-host disease, cardiac events, cartilage repair and Crohn's disease. As reported online in The Street, all have seen similar results: no adverse effects, but no significant positive effects. This has roused strong criticisms of the trial, and indeed the potentially misleading press release by Osiris giving the impression of success.