Swedish biopharma company Dicot Pharma has elucidated the novel mechanism of action behind its promising drug candidate, LIB-01.

This breakthrough aims to address a major unmet need for millions of men who do not respond to current standards of care.

Unlike widely used PDE5 inhibitors like Viagra (sildenafil) and Cialis (tadalafil), which act locally on blood flow in erectile tissue, LIB-01 targets the central melanocortin system. New preclinical findings confirm the compound enhances signaling through the MC4 receptor (MC4R), a key player in neural pathways governing sexual function, as well as hunger and energy metabolism.

New Research on Mechanism of Action

The research demonstrates that LIB-01 uniquely upregulates the body’s own production of both the MC4 receptor and its natural activator. Unlike other synthetic peptide agonists that only affect the MC4 receptors already present in the body, LIB-01 increases the body’s own production of both the receptor and its activator, the company explains.

This fundamental action on gene expression is believed to underpin the drug’s prolonged effect, which persists even after the compound has cleared the body. The specific role of MC4R was further confirmed by an observed attenuation of effect when an MC4R antagonist was co-administered.

“These research findings are another piece of the puzzle that explains the mechanism of action of LIB-01,” said Charlotta Gauffin, CSO of Dicot Pharma. She noted the results reinforce the candidate’s potential to treat underlying causes of ED and align with exploratory work in metabolic diseases, including conditions such as obesity and diabetes.

Phase II Clinical Data

This mechanistic insight builds upon positive results from a Phase IIa clinical trial study (NCT06703840) announced in October. The study involved 156 men with mild-to-moderate ED and evaluated three oral doses of LIB-01 administered over three days.

By week four, improvements in erectile function were observed across all treatment groups, regardless of the dose. The highest (50 mg) dose showed a clinically meaningful improvement, with a 4-point increase from baseline on the International Index of Erectile Function (IIEF-EF) scale. The effect was particularly pronounced in patients with moderate ED (baseline IIEF-EF 11-17), where the 50 mg group saw an 8.5-point shift.

Notably, 31% of patients in this higher-dose group became “complete responders,” achieving normal erectile function scores, compared to 0% on placebo.

Critically, the benefits were sustained at the eight-week follow-up. A pooled analysis of the 25 mg and 50 mg doses showed a statistically significant 6.5-point improvement over placebo.

“The pro-erectile effect of LIB-01 showed a maximum during the first four weeks and was sustained over the entire study period of eight weeks, whereas the pronounced placebo effect tapers off,” the data announcement stated, pointing toward a potential monthly dosing regimen. The treatment was well-tolerated, with mostly mild and transient gastrointestinal events.

Solidifying the Path Forward with IP and Financials

Backing its scientific progress, Dicot moved to strengthen its intellectual property position in November 2025 by filing a new patent application for LIB-01. The company’s existing patent protection currently extends to 2042. This strategic move aims to secure the asset’s value as it progresses.

Financial results for the third quarter of 2025, as per the interim report, show a solid cash position to fund ongoing development. The company reported cash and cash equivalents of SEK 66.3 million ($7 million). Dicot emphasizes that its runway is sufficient to advance key milestones. “The Phase IIa study results will form the basis for the continued development of LIB-01,” the company stated, confirming plans to initiate a Phase IIb study in 2026.