Pfizer says the US Food and Drug Administration has accepted for priority review a supplemental New Drug Application of its immunosuppressant Rapamune for lymphangioleiomyomatosis, a rare, often-fatal lung disease.

The sNDA is based on results from a trial involving 89 LAM patients with moderate lung impairment who were randomised to receive Rapamune (sirolimus) or placebo. Those treated with the drug for one year experienced stabilisation of lung function.

LAM is a rare progressive lung disease that usually affects women during their childbearing years and results from abnormal growth of smooth muscle-like cells. Over time, the abnormal growth of these cells can cause airway obstruction.
If approved, Rapamune would be the first FDA-approved treatment option for LAM and Pfizer expects a decision from the agency in June.

Susan Sherman, executive director of the LAM Foundation, which assisted with the recruitment of patients and logistics for the study, said that after 20 years of seeking treatment options, “we are thrilled about the possibility of getting a therapy approved to treat this rare and potentially deadly disease”.

Rapamune is currently indicated for the prevention of organ rejection in kidney transplant patients. Pfizer noted that it provided study drug and a portion of the funding but had no involvement in the design or conduct of the LAM trial.