Eiger BioPharmaceuticals Inc.'s experimental drug ubenimex failed to show an improvement in lower leg lymphedema — a chronic condition where excess fluid collects in tissues causing swelling — in a phase 2 trial.

The study, named Ultra, demonstrated no improvement of ubenimex over placebo in the primary endpoint of skin thickness and secondary endpoints of limb volume and bioimpedance.

Eiger said that an analysis suggests select, individual patient responses which clinical investigators believe warrant further exploration. It added that it does not plan additional clinical work but will support these additional analyses and will provide an update if findings suggest any potential pathway forward.

The drug previously failed another phase 2 trial, where it was tested to treat pulmonary arterial hypertension, a condition in which arteries of the lungs constrict, forcing the heart to pump harder.

Eiger BioPharmaceuticals' CEO and president, David Cory, said the company will focus on promising programs in its pipeline, including a new drug application for lonafarnib to treat Progeria, a rare genetic condition that causes a child's body to age fast. Cory said the company will also examine lonafarnib to treat hepatitis delta virus infection in a phase 3 study.

Palo Alto, Calif.-based Eiger BioPharmaceuticals develops treatments for rare and ultra-rare diseases.