Regeneron (REGN) said Monday that 84-week results from the phase 3 OPTIMA trial for Pasatru showed sustained efficacy in halting new, rogue bone growth outside of the skeleton and in reducing disease flare-ups in adults with ultra-rare genetic disorder fibrodysplasia ossificans progressiva, supporting long-term disease control.

Pasatru was recently approved by the FDA based on a 56-week, placebo-controlled study to reduce new abnormal bone growth and clinician-assessed flare-ups in adults with FOP.

The trial enrolled 63 adults with FOP, with 58 participants completing the double-blind extension phase through at least 84 weeks. Regeneron said both tested doses of Pasatru had a generally well-tolerated safety profile through week 84, consistent with results seen at 56 weeks.

Regeneron said a phase 3 trial of Pasatru in adolescents and children is planned to begin later this year.

Shares of Regeneron were up 2.7% in Monday trading.

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