Good news for Omeros Corporation(NASDAQ:OMER). The company sat down with the European Medicines Agency (EMA) this month to discuss the protocol for its application, and it turns out the agency is happy to accept a submission based on the same trial structure the FDA agreed to earlier this year. Why is this good news? Because it means Omeros only needs to conduct one phase III, and use the dataset to support both EMA and FDA applications, rather than one trial for each region. Big cost savings, and it should speed up the path to commercialization. Ahead of the trial, here’s a look at what’s under investigation, and what the company is looking for moving forward.

The drug in question is OMS721. It’s target indication is a condition called atypical hemolytic uremic syndrome (aHUS), which is a condition whereby the bodies complement system is unregulated. The complement system is the system in our bodies that attacks foreign particles, and in patients with aHUS, it’s over activity leads to what is called thrombotic microangiopathy – essentially, the forming of blood clots in small blood vessels. These blood clots cause all sorts of problems, including stroke, heart attack etc. As such, the condition is very fatal, and 40% of individuals that develop it die first time around, despite being treated with current SOC. Fortunately, it’s very rare. Of course, this doesn’t negate the need for a treatment option for patients who have it, and Omeros is working on providing that option.

OMS721 targets what’s called Mannan-binding lectin-associated serine protease-2, or MASP-2. MASP-2 is a protein that causes inflammation, which activates the complement system. The drug inhibits the activation of the system by inhibiting the action of MASP-2, and in turn, should control the otherwise unregulated activity of the system in aHUS patients. Regulating the complement system should stop the forming of the blood clots in the small blood vessels, and this, in turn, should stop the problems associated with the disease, as described above. It’s a long way round approach, but if it works, it could offer a solution to a very deadly disease that – right now – has very little in the way of treatment options for sufferers.

So, what about the trial? Well, we haven’t got too much information related to the design and the endpoints of the trial as yet – these are likely currently under determination on the back of the EMA meeting. We do know that a couple of phase IIs are currently underway investigating the safety and tolerability of the drug, and one of those, investigating OMS721 in subjects with thrombotic microangiopathies (TMA), will serve as a feeder trial for the phase III. In other words, the patients in this study will continue through to phase III and serve as the enrollment base for the study. For those not familiar with these conditions, and as a quick note, aHUS is a type of TMA, so we should get some idea of the efficacy of the drug in the latter before the trial kicks off. Specifically, we should know whether there is a clinical benefit at various dosing (low, medium, high) levels in aHUS patients from the results of the trial in this subset in phase II. Clinical activity is being assessed in the phase II by way of a coprimary endpoint (co with safety) that looks at plate count. Chances are the company will carry this primary endpoint forward with it to the phase III, but as yet this is not confirmed.

From a timeframe and milestone perspective, we are looking at the next few months for initiation of the phase III, with patients that have completed the phase II transferring across in to the phase III as they complete the former.  It could be a long trial (the phase III was a nearly four-year study), but hopefully we’ll get some insight by way of interim before completion and topline.