Osiris has a bit less than $4 a share in cash on hand, which seems an appropriate valuation for the company given Prochymal's uselessness. Prochymal is a drug derived from mesenchymal stem cells (MSCs), which are capable of differentiating into tissues that provide rigidity or stability in the body -- bone, cartilage, fat, tendon or muscle. MSCs may also possess anti-inflammatory properties and appear not to activate an immune response when transplanted into an unrelated or unmatched host, according to Osiris Graft-vs.-host disease, or GVHD, is a potentially life-threatening immune reaction that can occur in patients who have had bone-marrow transplants. In GVHD, immune cells from the donated bone marrow attack the recipient's organs and tissue. There are no approved drugs to treat GVHD, although steroids and other immunosuppressants are often used. Osiris is trying to salvage something positive from the failed Prochymal studies by data-mining to find two subgroups of patients -- those with steroid-refractory GVHD affecting the liver and gastrointestinal tract -- in which the drug appears to work better than a placebo. Osiris CEO Randy Mills, on a conference call Tuesday morning, says the company intends to meet with the Food and Drug Administration to discuss the Prochymal data and request a change to its existing expanded access program to allow patients with GVHD of the liver and GI emergency access to the drug. Left unsaid by Mills, however, is that if Prochymal is benefiting GVHD patients with liver and GI involvement, it is likely doing harm to patients with GVHD of the skin, the most common form of the disease.