MorphoSys AG (MPSYF.PK) announced results from the phase 1b/2a clinical trial evaluating its proprietary HuCAL antibody MOR103 in rheumatoid arthritis or RA patients. The company noted that the positive data make MOR103 the first anti-GM-CSF antibody to demonstrate clinical efficacy in RA. The results demonstrate the compound's potential to become an important new drug in an area of unmet medical need.
MorphoSys stated that it will submit a late-breaking abstract for a forthcoming conference to present the clinical trial results before the end of the year.
The best response was achieved in the 1.0 mg/kg dose cohort with an ACR20 score of 68% at week 4, which was significantly higher than in the control arm (p<0.0001). Of particular importance was the fast onset of action observed: within 2 weeks, up to 40% of patients achieved an ACR20 score. Improvement of DAS28 scores was rapid and significant over the treatment period of the study. MRI scans revealed a reduction of synovitis according to the RAMRIS system at week 4.
MOR103 was safe and well-tolerated at all doses administered. There were no drug-related serious adverse events. No obvious differences in the adverse event rate between the MOR103 and placebo groups were observed, the company said.
In the randomized, double-blind, placebo-controlled phase 1b/2a trial in 96 mild to moderate RA patients, MOR103 was administered in four weekly doses of 0.3 mg/kg, 1.0 mg/kg or 1.5 mg/kg. The trial, which was designed to look in particular at the onset of the therapeutic effect, was conducted in 26 centers in Germany, Netherlands, Poland, Bulgaria and Ukraine. The majority of the trial participants were on a stable regimen of disease modifying anti-rheumatic drugs.
The primary endpoint of the trial was to determine the safety and tolerability of multiple doses of MOR103 in patients with active RA. Secondary outcome measures were pharmacokinetics, immunogenicity, and the drug's potential to improve clinical signs and symptoms of RA as measured by DAS28, ACR20/50/70 and EULAR response criteria, MRI imaging for synovitis and bone edema as well as patient reported outcomes.
The company stated that it will now proceed with its plans to seek a commercial partner for further development of the program. In addition to the RA study, MOR103 is currently being evaluated in a phase 1b dose-escalation study in multiple sclerosis. Results of a phase 1 pharmacokinetic study in healthy volunteers to evaluate a subcutaneous formulation of MOR103 will be available shortly, the company said.
For comments and feedback contact: editorial@rttnews.com
Business News
June 05, 2026 16:18 ET A busy week for economic news flow saw a slew of reports being released that reflected the trends in the U.S. labor market. In Europe, economic growth and inflation data gained attention as the European Central Bank and Bank of England head for policy session later in the month. In Asia, the monetary policy session of the Indian central bank was in focus as the country, a major oil importer, reels under the pressures of a weaker rupee and rising inflation.