Mesoblast (ASX:MSB) will issue 10.2 million ordinary shares to Osiris Therapeutics as contingent consideration in relation to the approval of its cell treatment by the US Food and Drug Administration (FDA), according to a Monday Australian bourse filing.

The FDA approved the firm's mesenchymal stromal cell therapy, Ryoncil, in December 2024, according to an earlier filing.

The shares will be subject to voluntary escrow for 12 months from the date of issue, the filing said.

Mesoblast's shares fell 6% during trading on Tuesday.