Amicus pays $30M to Dimerix for late-phase rare kidney drug

Amicus Therapeutics, a specialist in orphan drugs, has made a significant move by acquiring the U.S. rights for DMX-200, a promising phase 3 treatment for focal segmental glomerulosclerosis (FSGS), from Melbourne-based Dimerix. This strategic acquisition, valued at $30 million in cash, positions Amicus as a potential competitor to Travere Therapeutics in the rare disease market. Currently, the FDA has not approved any specific therapy for FSGS, but Amicus aims to address this significant unmet medical need through its new partnership.

Dimerix initiated a phase 3 clinical trial for DMX-200, a CCR2 inhibitor targeting FSGS, in 2022. The Australian biotech has collaborated with the FDA to agree on using proteinuria as a primary endpoint for obtaining traditional approval. Although interim results on DMX-200's effects on proteinuria were released last year, additional data from ongoing enrollment and forthcoming interim analyses could pave the way for FDA approval submissions.

In addition to the initial cash payment, Amicus has committed to potential additional financial milestones. These include up to $75 million for development and regulatory achievements, $35 million contingent upon the drug's first sale, and up to $410 million linked to sales milestones, with an extra $40 million for possible future indications.

Despite Travere's recent FDA filing for their FSGS treatment, Filspari, Amicus remains confident in the potential of DMX-200. Jeffrey Castelli, Amicus' chief development officer, emphasized the unique approach of DMX-200, which focuses on targeting inflammatory signaling in damaged kidneys, unlike other treatments that concentrate on hemodynamic factors. This differentiation could mean that some patients will respond more favorably to DMX-200, providing physicians with multiple treatment options for FSGS.

Castelli pointed out that DMX-200 offers insights into the inflammatory component of the disease, potentially identifying patients who might respond best to the treatment. He believes that these insights will help doctors focus on the most suitable treatment options for individual patients during clinical trials.

Interestingly, Castelli compared DMX-200 to earlier CCR2 inhibitors, highlighting its distinct mechanism. Previously, ChemoCentryx, now part of Amgen, had collaborated with Vifor Fresenius Medical Care Renal Pharma on a CCR2 inhibitor, but their FSGS program was halted after unsuccessful phase 2 results in 2020. Castelli explained that traditional binding inhibitors prevented MCP-1 docking, leading to a rebound effect where MCP-1 levels surged, counteracting the inhibitor's effectiveness. In contrast, DMX-200 employs a downstream blocking mechanism that allows MCP-1 to dock and subsequently degrade, avoiding the rebound effect.

Amicus aims to maximize the efficacy of DMX-200's mechanism in curbing monocyte inflammation, crucial for treating FSGS. This approach ensures that monocytes can continue their vital functions, such as combating infections, outside the kidney.

In summary, Amicus Therapeutics' acquisition of DMX-200 from Dimerix highlights its strategic pursuit of promising, de-risked assets for addressing rare diseases like FSGS. With a unique inflammatory signaling approach, DMX-200 has the potential to offer a new therapeutic option for FSGS patients, complementing existing treatments and expanding physicians' arsenal in managing this rare kidney disorder.