Idera's dermatomyositis drug flops in phase 2

stop sign (knerri61/Pixabay)
Idera is also developing IMO-8400 for B-cell lymphoma—that program is currently in phase 1. (Walter Knerr)

Idera Pharmaceuticals' toll-like receptor (TLR) antagonist, IMO-8400, missed its primary endpoint in a phase 2 trial involving adults with dermatomyositis, a group of rare muscle diseases characterized by muscle inflammation and weakness, as well as a skin rash. 

Topline data show that the candidate, which blocks TLR 7,8 and 9, failed to beat placebo in making a statistically significant change from baseline in the Cutaneous Dermatomyositis Disease Area and Severity Index (CDASI) activity score, a measure of skin disease severity. 

Thirty patients participated in the trial, receiving either a 0.6 or 1.8-mg/kg dose of IMO-8400 or placebo once a week for 24 weeks. The mean CDASI score was in the severe range for all three groups, even though more than half of the patients were also being treated with immunosuppressive drugs and/or systemic corticosteroids. 

There is no cure for dermatomyositis. Current treatments focus on controlling inflammation and skin symptoms, but systemic therapies can lead to nasty side effects. 

"The company would like to recognize the efforts of the investigators from this trial and importantly the patients who entered this trial in the hope that IMO-8400 may have been an effective treatment for their disease," Idera said in a statement. 

Idera is also developing IMO-8400 for B-cell lymphoma—that program is currently in phase 1. The biotech is also working on a TLR9 antagonist for use in immuno-oncology and is partnering with Vivelix on a TLR 7, 8, 9 antagonist for autoimmune diseases. 

The company unveiled encouraging data in September, showing a combination of its TLR9 drug IMO-2125 and Bristol-Myers Squibb's PD-1 blocker Yervoy improved outcomes for melanoma patients who had progressed after being treated with checkpoint inhibitors. The combo posted an objective response rate of 44%, emboldening Idera to push forward into phase 3.