Unity Biotech Arthritis Drug Flunks Phase 2, Spelling Program’s End

Unity Biotechnology’s ambition to develop drugs that treat diseases of aging has failed its first test as its lead candidate, an osteoarthritis treatment, could not beat a placebo in a mid-stage clinical trial.

South San Francisco-based Unity (NASDAQ: [[ticker:UBX]]) is developing drugs that remove senescent cells, which are cells that have stopped dividing but still secrete large quantities of proteins associated with aging. The company says that as people grow older, these cells accumulate and drive age-related diseases of the eyes, heart, brain, and joints. Lead Unity compound UBX0101 was developed as a treatment for moderate-to-severe osteoarthritis of the knee. By blocking the interaction of two proteins, p53 and MDM2, the small molecule drug was hoped to trigger the elimination of senescent cells that contribute to the condition.

Unity tested its drug in a Phase 2 study enrolling 183 patients with moderate-to-severe osteoarthritis knee pain. Those patients were randomly assigned to receive a knee injection of one of three doses of the Unity drug, or a placebo. The study was designed to last 24 weeks but the main goal was measured at week 12—the magnitude of improvement in osteoarthritis pain according to a widely used rating scale used to assess its intensity.

At the 12-week mark, the placebo response was “both large in magnitude and long in duration,” Unity said in an investor presentation. None of the three doses of the test drug was able to distance itself from the sham injection, and the company said it would not advance UBX0101 to a Phase 3 clinical trial. The drug was well tolerated by patients at all doses and the only dropout from the study was a patient who reportedly had a cardiovascular event unrelated to the study. Unity plans to present the full results from the Phase 2 study, as well as the data from Phase 1 testing, at a future medical meeting.

Shares of Unity sank more than 66 percent on Monday from Friday’s $12.43 per share closing price. That slide continued Tuesday as shares slipped another 17 percent nearing $3 apiece in morning trading.

Unity launched in 2016 and went public two years later. With its lead drug now sidelined, the biotech plans to turn its focus to its most advanced preclinical program, UBX1325, which is being developed for three eye diseases: age-related macular degeneration, diabetic macular edema, and diabetic retinopathy. The drug goes after a protein called Bcl-XL, a different target than UBX0101.

In its release of financial results for the second quarter, Unity reported having $39.6 million in cash and cash equivalents. The company believes that it has enough money to last “well into 2022.”

Photo by Flickr user Esther Max via a Creative Commons license.