LG Chem’s US partner starts phase 2 study for rare obesity pill

LG Chem said that Rhythm Pharmaceuticals, a U.S.-based company, has initiated the first patient dosing for a phase 2 clinical trial of LB54640, a novel oral drug for rare obesity disorders, following a global license acquisition for the candidate from LG Chem earlier this year. 

LB54640 is an MC4R (melanocortin-4 receptor) agonist developed by LG Chem. LG Chem had licensed this compound to Rhythm Pharmaceuticals for global development in January 2024.

The total value of the deal is $350 million, with an upfront payment of $100 million, development and commercialization milestones of up to $250 million, and annual royalties based on Rhythm Pharmaceuticals' annual sales.

Patient recruitment is a significant challenge in clinical trials for orphan drugs due to the small patient population. LG Chem expected that partnering with Rhythm Pharmaceuticals, which has invested considerable resources in identifying potential patients, would enable more efficient drug development.

The trial will enroll 28 patients, aged 12 and older, suffering from hypothalamic obesity—a condition characterized by damage to the hypothalamus affecting appetite control, either congenitally or acquired.

The primary efficacy endpoint will assess changes in body mass index (BMI) at the 14-week mark of drug administration, with an extension study planned to evaluate long-term safety over 52 weeks.

“Based on LG Chem’s significant preclinical work and encouraging results from a Phase 1 trial, we believe LB54640 has the potential to be an effective oral therapy for treating MC4R pathway diseases without hyperpigmentation,” Rhythm Pharmaceuticals CEO and President David Meeker said.  “We look forward to advancing this molecule with the goal of offering a full portfolio of treatment options to patients struggling with hyperphagia and severe obesity and ensuring they get the treatment that is right for them.”