MedPacto Wins Australian Phase 1 Approval for Bone Disease Drug Candidate MP2021, Aiming to Diversify Pipeline

MedPacto will begin global clinical development of MP2021, a drug candidate for bone disease, after receiving approval for its Australian Phase 1 trial plan.

MedPacto disclosed on the 2nd that it had received approval for the MP2021 Phase 1 trial plan from Australia’s Human Research Ethics Committee. The approval came about two and a half months after the company submitted its application on July 15.

The trial is designed as a randomized, single-blind, placebo-controlled, single-ascending-dose study to evaluate the safety and tolerability, as well as the pharmacokinetic and pharmacodynamic characteristics, of a single intravenous dose of MP2021 in healthy adults.

The trial will be conducted at Nucleus Network Sydney, a specialized clinical trial site in Sydney, Australia. Up to 32 participants will be enrolled and dosed sequentially in as many as four cohorts: 1.5 mg/kg, 3 mg/kg, 6 mg/kg and, optionally, 9 mg/kg.

The primary endpoints are the incidence and severity of all treatment-emergent adverse events and their relationship to the study drug. Changes from baseline in blood and biochemical tests, vital signs, 12-lead electrocardiograms and physical examination findings will also be analyzed.

The company said it plans to begin dosing the first participant in the fourth quarter of 2026, complete trial procedures by the fourth quarter of 2027 and finish the study by the end of December 2027.

MP2021 is a first-in-class investigational drug candidate that targets TM4SF19, a cell membrane protein involved in the formation of multinucleated osteoclasts, which break down bone. It works by inhibiting osteoclast multinucleation to block bone resorption and bone loss.

In preclinical studies, MP2021 inhibited bone loss in a mouse model of osteoporosis and showed a dual effect in an animal model of rheumatoid arthritis, preventing inflammation, cartilage damage and bone erosion. The studies also found that it may prevent the rapid rebound bone loss that occurs after treatment is stopped.

MedPacto’s decision to choose Australia as the site of its first clinical trial is viewed as a strategic one, taking into account the country’s expedited clinical trial approval process and the potential for data generated under Good Clinical Practice standards to be recognized by leading regulatory agencies.

The trial entry is also significant for pipeline diversification. MedPacto has focused on vactosertib, a TGF-beta inhibitor, but has faced criticism over its high dependence on a single drug candidate.

The company is also conducting preclinical research on an antibody-drug conjugate candidate in collaboration with a major Japanese pharmaceutical company, based on the TM4SF19 target. The start of clinical development is expected to bring discussions about a potential licensing deal into sharper focus.

However, whether the positive preclinical efficacy will be demonstrated in human trials remains an open question. Only about 10% of drug candidates that enter Phase 1 reach marketing approval. The safety threshold and pharmacokinetic profile established in this trial are expected to be key benchmarks in early licensing negotiations.