Omeros Corporation, a clinical-stage biopharmaceutical company, has reported results from its first pivotal phase III clinical trial evaluating OMS103HP in patients undergoing arthroscopic partial meniscectomy surgery. In this multi-centre, double-blind, phase III clinical trial comparing OMS103HP to vehicle control in 344 subjects, the pre-specified primary endpoint was the Symptoms Subscale of the Knee Injury and Osteoarthritis Outcome Score (KOOS) – a patient-reported measure that is comprised of questions about knee swelling, clicking, catching and stiffness.

In addition, pain measured in the early postoperative period was a pre-specified secondary endpoint. Although the Symptoms Subscale of the KOOS did not reach statistical significance, OMS103HP achieved statistically significant (p=0.0003) reduction of postoperative pain . The pain reduction data were similar in magnitude to those in the phase II clinical trial.

OMS103HP also demonstrates improvement across a series of pain-related assessments including postoperative narcotic usage (with more than twice as many OMS103HP-treated subjects taking no postoperative narcotics), incidence of inflammatory adverse events, tourniquet use, and crutch use as well as time to discontinuation of crutches and return to work, a number of which also achieved statistical significance. In this study, as in the earlier clinical trials, OMS103HP was well tolerated. Given the strength and consistency of the data in this phase III clinical trial, Omeros' second OMS103HP phase III trial remains on track and will begin in the first half of 2013.

"The data from this phase III trial are compelling and demonstrate the benefits of preemptive and multimodal treatment during surgery," stated William E Garrett, Jr., MD, professor of orthopaedic surgery and team physician at Duke University. "Early postoperative pain is predominantly inflammatory pain, and control of postoperative pain and inflammation is critical to functional recovery in arthroscopy patients. While OMS103HP demonstrated positive KOOS data in the phase II trial, the absence of similar data in this trial does not detract from the drug's therapeutic value in light of its reduction of inflammatory pain. Arthroscopy patients with significant early postoperative pain and inflammation generally face a slower and more difficult recovery."

OMS103HP, added to standard irrigation solution used during arthroscopy, is Omeros' proprietary PharmacoSurgery product designed to provide a multimodal approach to reduce pain and inflammation following arthroscopic surgery. Inhibiting inflammation and resultant postoperative pain is critical to the management of arthroscopy patients. Comprised of only anti-inflammatory active ingredients without any anesthetic agents, such as lidocaine or bupivacaine, and delivered directly to the joint in the arthroscopic irrigation solution, use of OMS103HP avoids the frequently reported damage to cartilage cells due to intraarticular delivery of local anesthetics as well as the detrimental effects of systemically delivered analgesics.

"These consistent results – better pain reduction together with less narcotic usage and less frequent incidence of postoperative inflammatory problems – underscore the strength of OMS103HP's unique approach to improving arthroscopy outcomes," stated Christopher C Kaeding, MD, professor of orthopedic surgery and head team physician at The Ohio State University. "Orthopaedic surgeons understand the importance of preventing postoperative pain and inflammation, and there is increasing evidence that intraoperative joint inflammation is detrimental to the long-term health of the joint. Treatments currently available to us, however, are administered after the surgical insult. OMS103HP, delivered intraoperatively, provides an opportunity to inhibit inflammation and related surgical problems before they begin. OMS103HP could become a key component in the management of arthroscopy patients."

Results from this first phase III arthroscopic meniscectomy clinical trial are expected to be presented at an upcoming major orthopedic sports medicine meeting. Omeros also plans to publish the results in a leading peer-reviewed arthroscopy journal.

"We are pleased with the outcome of this trial," said Gregory A Demopulos, MD, chairman and chief executive officer of Omeros. "While not meeting all endpoints, the consistently positive results on pain reduction and the series of related inflammatory measures mark a clear path to approval of OMS103HP. The arthroscopy market is large and these data, together with an early 2013 NDA submission for our ophthalmic surgery product OMS302, set the stage for potentially two near-term market launches."

OMS103HP is Omeros' PharmacoSurgery product candidate being developed for use during arthroscopic procedures, including partial meniscectomy surgery, and was designed to provide a multimodal approach to preemptively block the inflammatory cascade induced by arthroscopy. OMS103HP is a proprietary combination of anti-inflammatory/analgesic active pharmaceutical ingredients (APIs), each with well-known safety and pharmacologic profiles. Comprised of only anti-inflammatory active ingredients without any anesthetic agents, such as lidocaine or bupivacaine, and delivered directly to the joint in the arthroscopic irrigation solution, use of OMS103HP avoids the frequently reported damage to cartilage cells due to intraarticular delivery of local anesthetics as well as the detrimental effects of systemically delivered analgesics. Each of the APIs in OMS103HP are components of generic, FDA-approved drugs that have been marketed in the United States as over-the-counter or prescription drug products for over 15 years and have established and well-characterised safety profiles.

Control of postoperative inflammation and resultant pain is critical to functional recovery in arthroscopy patients. In phase II and phase III clinical trials that evaluated OMS103HP in patients undergoing partial meniscectomy surgery, OMS103HP provided clinically meaningful benefits related to postoperative pain and inflammation.

Arthroscopy is a minimally invasive surgical procedure in which a miniature camera lens is inserted into an anatomic joint, such as the knee, through a small incision in the skin. Through similar incisions, surgical instruments are also introduced and manipulated within the joint. Arthroscopic meniscectomy is used to treat a torn meniscus cartilage in the knee. Only the torn segment of the meniscus is removed. Postoperative recovery to normal function may take months and, in good part, is a function of postoperative pain and inflammation. In 2012, over four million arthroscopic procedures were performed in the United States and over eight million globally.

Omeros is committed to discovering, developing and commercializing products targeting inflammation, coagulopathies and disorders of the central nervous system.