CellPro Inc. got a lump of coal in its Christmas stocking from the FDA, in the form of a letter notifying the company that the PMA for its Ceprate SC Stem Cell Concentration System isn't approvable without amendment.

The agency's letter said the measures needed to make the PMA approvable include the possibility of additional studies of platelet engraftment, patient survival and other issues. CPRO hasn't yet discussed the letter with the FDA, which was closed for the New Year's holiday.