Galectin Therapeutics recently reported interim data from an open-label exploratory Phase 2a study investigating its development-stage galectin-3 (gal-3) inhibitor, GR-MD-02, in patients with moderate to severe plaque psoriasis.

In May, Galectin had reported that 12 weeks after treatment with GR-MD-02, patients experienced a significant improvement in PASI (Psoriasis Area and Severity Index) scores. The small exploratory study was conducted in four patients that were treated with seven infusions of 8 mg/kg of GR-MD-02 every other week. This positive improvement in PASI scores led to a treatment extension for an additional 12 weeks with the same dose and dosing interval (13 total infusions).

At the moment, four patients with moderate to severe plaque psoriasis have completed 24 weeks of treatment. A fifth patient has concluded 12 weeks of therapy with GR-MD-02.

Despite the treatment extension period, there was a only marginal additional psoriasis improvement in the original four patients.

“We are pleased to report that there is clinically meaningful activity of GR-MD-02 for the treatment of moderate to severe psoriasis,” Galectin President and CEO Dr. Peter G. Traber, MD, also chief medical officer, said in a press release. “Moreover, this activity in a human disease, strongly associated with NASH [non-alcoholic steatohepatitis] and increased galectin-3 expression, suggests that GR-MD-02 may also have activity in NASH, which remains the company’s primary target.”

Traber said that while the improvement among patients is significant, the company must look at those improvements in the context of treatments either in development or already on the market.

“The primary endpoint for these existing agents is a 75 percent improvement in PASI, and none of our patients reached that level of improvement at the dose level and duration administered in the study,” Traber said. “There are potential advantages which GR-MD-02 might have over biological agents, such as safety and cost, and the current safety profile of GR-MD-02 does support the possibility of studying higher doses or a more frequent dosing regimen for psoriasis.”

But without more study, “these potential advantages remain untested,” he said.

This exploratory psoriasis clinical trial was conducted because there was an unanticipated positive effect on psoriasis in a patient with NASH in Galectin’s Phase 1 clinical study in patients with liver disease.

Given the company’s concentration on the Phase 2 clinical program in NASH patients with advanced fibrosis and cirrhosis, additional clinical trials to develop GR-MD-02 as a potential treatment for psoriasis are not expected to happen. Galectin’s spokespeople said the company may conduct additional clinical trials in the future of GR-MD-02 in patients with psoriasis either alone or through collaborations interested in taking this forward.

“The results of the psoriasis trial confirm GR-MD-02 is active in a human disease,” Traber said. “The company continues to pursue the application of GR-MD-02 for the treatment of NASH with liver fibrosis and cirrhosis, which has always been the primary focus of our business.”