Spyre falls after arthritis drug misses development target

Shares of drug developer Spyre Therapeutics SYRE.O fall 11.35% to $95.17 premarket

Spyre's experimental drug, SPY072, improved rheumatoid arthritis symptoms in a mid-stage trial, but its effect fell short of an internal target for developing it as a monotherapy for the condition

The study tested two doses of SPY072 compared to placebo in patients with moderate to severe rheumatoid arthritis whose disease had not responded adequately to prior treatments

The higher dose helped 63% of patients achieve at least 20% improvement in symptoms, compared with 43% on placebo

Spyre expects results from studies of SPY072 in psoriatic arthritis and axial spondyloarthritis, an inflammatory condition affecting the spine, later this year

As of last close, shares have more than tripled YTD