COLUMBIA, Md. ( TheStreet) --Another clinical trial, another failure for Osiris Therapeutics ( OSIR) and its do-nothing stem cell therapy.

This time, Osiris' experimental Prochymal therapy failed to slow the progression of Type 1 diabetes compared to a placebo after one year of treatment.

Add diabetes to the long list of diseases in which Prochymal has proven to be ineffective, including graft-versus-host disease, knee cartilage repair, Crohn's disease and heart attack.

Osiris never likes to acknowledge Prochymal's many failures and Tuesday's announcement of the diabetes trial result is no different. The company buried the study's disappointing data in its press release: "No significant differences in the rates of disease progression, as measured by stimulated C-peptide levels at the one year time point, have been observed."

Prochymal's side effect profile was apparently as benign as placebo, which makes sense since Prochymal -- a stew of off-the-shelf adult stem cells that gets injected into patients -- has proven to be nothing more than a placebo.

Osiris notes a "trend" towards fewer incidences of low blood sugar reported by Prochymal-treated patients compared to those treated with a placebo at one year. What Osiris doesn't say is that having something vaguely positive to report about one of six secondary endpoints matters not at all when the study's primary endpoint fails.

Efforts by Osiris to convince regulators in Canada to approve Prochymal in graft-versus-host disease appear stalled and the company has said nothing recently about moving forward with a U.S. approval filing for the same indication.

Osiris finds it easier apparently to bamboozle retail investors about failed stem-cell therapies than regulators.

--Written by Adam Feuerstein in Boston.

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Adam Feuerstein writes regularly for TheStreet. In keeping with company editorial policy, he doesn't own or short individual stocks, although he owns stock in TheStreet. He also doesn't invest in hedge funds or other private investment partnerships. Feuerstein appreciates your feedback; click here to send him an email.