US-based Omeros has started dosing patients in its new Phase ll clinical trial of OMS721 in corticosteroid-dependent renal diseases.

OMS721 is the company’s main mannan-binding lectin-associated serine protease-2 (MASP-2) inhibitor being developed for complement-related diseases.

The Phase ll trial is evaluating the effects of OMS721 on kidney function in patients with corticosteroid-dependent renal diseases.

The trial expands Omeros’s MASP platform, which includes an OMS721 Phase lll programme in progress to treat atypical hemolytic uremic syndrome (aHUS), as well as an ongoing Phase ll programme of OMS721 to treat other thrombotic microangiopathies (TMAs).

The trial includes patients with corticosteroid-dependent IgA nephropathy, membranous nephropathy, C3 glomerulopathy and lupus nephritis.

"Currently, there are no FDA-approved treatments for corticosteroid-dependent patients who have persistent renal inflammation."

It is noted that evidence implicates the complement system, and specifically the lectin pathway, in the pathogenesis of each of these serious diseases.

The company noted that despite ongoing treatment with corticosteroids, these patients have evidence of progressive kidney disease and are at high-risk of kidney failure and dialysis.

Constant corticosteroid use carries major risks to patient and is associated with serious side-effects.

Currently, there are no FDA-approved treatments for corticosteroid-dependent patients who have persistent renal inflammation.

Treatments for these diseases that recover kidney function, slow disease progression or avoid long-term corticosteroid use would meet a significant unmet medical need.

The Phase ll trial of OMS721is enrolling a total of around 16 patients across separate cohorts for each disease.

The trial is assessing markers of kidney injury and will evaluate whether OMS721 allows a reduction in diseased patients’ corticosteroid requirements. Patients are expected to receive 12 weeks of OMS721 treatment and will undergo protocol-prescribed corticosteroid tapering. Data from this trial is expected to be reported in the second half of this year or the first half of next year.

If this trial demonstrates evidence that OMS721 improves kidney function, slows disease progression or reduces corticosteroid use in these patients, the company aims to request breakthrough therapy designation from the FDA and to initiate a Phase lll programme that meets the requirements for accelerated approval.

Omeros currently has the worldwide rights to MASP-2 and all therapeutics targeting MASP-2, a new pro-inflammatory protein target involved in activation of the complement system, which is an important component of the immune system.