Thank you, Jennifer and good afternoon everyone. We appreciate you joining us for today's call. We'll start with a corporate update then an overview of our first quarter 2022 financial results followed by a more detailed financial summary. Joining me on the call today are Mike Jacobsen, Nadia Dac, Cathy Melfi, and Steve Whitaker, our respective heads of Finance, Commercial, Regulatory, and Clinical. Let's begin with our MASP-2 program and specifically narsoplimab in stem cell transplant-associated thrombotic microangiopathy or TA-TMA. In February, we had a Type A post-action meeting with FDA following receipt of our complete response letter. In our briefing package and during the meeting, we addressed all of FDA's stated concerns. FDA was delayed in providing their final meeting minutes to us. When we finally received them, there were no new requests. Yet we found that the division had repeated a number of critiques that we feel had not only been adequately addressed, but also some that we view as demonstrably inaccurate based on FDA's own minutes and other official communications. After close review and discussions with our legal and regulatory advisers, we began drafting a dispute resolution request an official FDA pathway that allows the sponsor to appeal a decision by an FDA division to a higher deciding authority in the agency, in this case the Office of New Drugs. With the assistance of our legal and regulatory advisers including recent former FDA office and division directors, we are now completing the draft request. We believe that it lays out a very strong case across all components: our data, the documented regulatory history not only FDA precedent, but precedent established by our specific division, and the literature. Now, that the document is drafted and we have assessed the strength of both our position and the document our path forward is clear. Based on the strength of our case and on the input and recommendation of our legal and regulatory advisers, we are foregoing negotiation with the division and proceeding directly to dispute resolution. We believe that this is the most expeditious route to approval. Dispute resolution by design is rapid. Our request is clear and that is regular approval based on the data in our existing BLA. With respect to timing we're incorporating comments from our advisers and have begun the process of regulatory publishing required prior to submission. We expect to submit within the next couple of weeks. We are requesting a meeting with the Office of New Drugs. That meeting according to FDA's PDUFA commitments should be held within 30 days of the request. A decision is then to be rendered within 30 days following the meeting. Although, public statistics indicate that most appeals are denied those statistics are misleading. And the collective experience of our advisers at both Covington & Burling and Hyman, Phelps & McNamara, the good majority of their appeals even if formally denied result in a favorable outcome for the sponsor. We are confident in our data and in our submission. We believe that narsoplimab should have been approved last fall and we are committed to getting it approved as quickly as possible. In the meantime, transplanters continue requesting narsoplimab under our compassionate use program for their patients with TA-TMA and we make every attempt to provide it, especially for children. Two recent examples include two seven-year-old little girls, one in Italy and the other in Australia, one who had failed defibrotide and the other had failed both defibrotide and eculizumab. With narsoplimab treatment, both children have recovered and have been able to return home. The results from our narsoplimab pivotal trial in TA-TMA were recently published in the Journal of Clinical Oncology or JCO, one of the premier medical journals and the flagship publication of the American Society of Clinical Oncology. Authored by a group of leading international transplanters, the manuscript was published online by JCO a few days prior to the start of Tandem 2022. Held this year in South Lake City, the Tandem conferences comprised the joint annual meetings of the American Society for Transplantation and Cellular Therapy or ASTCT and the Center for International Blood and Marrow Transplant Research. As part of the conference, Omeros received an award from the president of ASTCT, crediting Omeros for our work in raising awareness of TA-TMA and advancing the medical and scientific understanding in the field. The keen interest in narsoplimab was palpable among physicians, pharmacists, nurses and patient advocacy groups in attendance at the meeting, underscored by the number of times our newly published manuscript was downloaded from the JCO website, more than 2,000 times during the first week of availability and more than 3,000 times only two short weeks since the Tandem Conference. In March, at the European Society for Blood and Marrow Transplantation or EBMT, important aspects of TA-TMA and narsoplimab were presented. One presentation reported on a rigorous literature review of the natural history of high-risk TA-TMA, which is the same patient population enrolled in the narsoplimab pivotal trial. In the literature review patients who received only supportive measures, had just a 23% response rate, even though the definition of response for the literature review was less stringent than that used in the narsoplimab pivotal trial. Just to refresh your memory, in that pivotal trial Omeros found a 61% response rate to narsoplimab. Another EBMT presentation was a case report on a nine-month old girl at Emory University who had failed treatment with eculizumab whose life the investigator believes was saved by narsoplimab. All of us at Omeros along with the community of physicians, patients and caregivers searching for an effective therapy for TA-TMA look forward to wider availability of narsoplimab following regulatory approval and we expect that we will get there. Our narsoplimab IgA nephropathy program also has made good progress. Enrollment in our Phase III ARTEMIS-IGAN trial has accelerated and we continue to target reading out nine-month data on proteinuria in the first half of next year. The trial is assessing both an overall population of IgAN patients with baseline proteinuria greater than or equal to 1 gram per day and a population of patients with more severe disease whose baseline proteinuria is at least 2 grams of proteinuria per day. The trial is designed so that either population can support accelerated or regular approval. Our IgAN efforts in China are also proving successful. Our investigational new drug application for narsoplimab and IgAN was approved in China and we look forward to completing the few remaining regulatory requirements and initiating enrollment there as soon as possible. Our Phase 3 narsoplimab trial in patients with aHUS also is ongoing, although, as previously, reported this program has been deprioritized relative to our other MASP-2 and MASP-3 programs. Narsoplimab is also being evaluated for the treatment of hospitalized COVID-19 patients in the I-SPY platform trial, sponsored by Quantum Leap Healthcare Collaborative. The trial has evaluated multiple drugs as potential COVID-19 therapeutics and to date none have been publicly reported to show a benefit relative to the background therapy in the trial. We are limited in what we can say about the trial per our agreement with Quantum. We can confirm though that in the latter part of last year, concurrent with stopping enrollment in the narsoplimab treatment arm, Quantum initiated discussions regarding additional clinical work focused on narsoplimab. For various reasons, that study did not go forward. We would very much like to report the data to-date and are working collaboratively with Quantum to finalize analysis. As soon as we can, we all look forward to sharing the outcome of the trial. Meanwhile, work at the Omeros-Cambridge Center for Complement and Inflammation Research or OC3IR continues to provide important contributions to the field's understanding of the mechanism of SARS-CoV-2 and the pathophysiology of COVID-19. A manuscript by Ali et al. published last month in Frontiers in Immunology detailed the secondary infection in COVID-19. A significant cause of morbidity and mortality in COVID is driven by complement hyperactivation, most likely lectin-pathway hyperactivation. A second manuscript, delayed to include additional new data has now been submitted for publication and demonstrates that, in fact, it is hyperactivation of the lectin pathway that causes complement dysfunction in acute severe COVID-19 and that narsoplimab rapidly normalizes complement function, restoring the body's infection fighting ability. As more and more research from groups around the world is published, demonstrating the importance of complement in COVID-19 and specifically, the central role of the lectin pathway interest continues to increase in narsoplimab, as a treatment for acute severe COVID-19 and also potentially, as prevention or treatment of long COVID or PASC. This has resulted in receptive discussions with Biden administration COVID-19 advisors, and principals at NIH. Our team continues to advance research in both acute severe and long COVID-19. With respect to life cycle management for our MASP-2 program OMS1029, our long-acting second-generation MASP-2 antibody, is advancing quickly. Having successfully completed nonclinical toxicology studies, without a safety signal of concern, the Phase I trial is planned to begin this summer. With expected dosing in humans of once monthly, to even once quarterly OMS1029, allows us to pursue a range of indications complementary to those of narsoplimab. We've also made good progress on our small molecule MASP-2 inhibitors, designed for oral administration and we're driving to advance a lead oral candidate to the clinic, as soon as possible. Let's now turn to OMIDRIA. As we discussed, on our year-end earnings call, OMIDRIA completed the strategic divestiture to Rayner Surgical last December. The transaction with Rayner, required us to classify all historical OMIDRIA revenue and expenses into discontinued operations, as well as, to record the royalties we earn as a reduction of the OMIDRIA contract royalty asset on our balance sheet. Our royalty rate for US net sales of OMIDRIA, is 50%. Given the required reclassification of OMIDRIA revenues and expenses, our revenues for the first quarter were reported as zero and our net loss from continuing operations recorded as $35 million compared to $45.3 million in the prior year quarter. Our overall loss for the current quarter was $33 million, or $0.53 per share compared to $35.1 million or $0.57 per share in the first quarter of last year. Our noncash expenses were $4.2 million or $0.07 per share, compared to the same quarter last year of $4.1 million and $0.07 per share. In total, our change in cash and investments from year-end was a decrease of $15 million. Rayner reported OMIDRIA net sales of $27.8 million for the first quarter. This represents an approximately, 31% increase over the $21.1 million of sales for the first quarter of 2021. As I mentioned, we earn royalties at 50% of Rayner net sales, which translates to $13.8 million. As discussed in prior calls, when considering the royalty we receive and the reduction in our operating costs, we retain approximately 70% of the OMIDRIA operating profit when royalties are at 50% of OMIDRIA net sales. During the quarter, we worked closely with Rayner to help ensure a smooth transition of the product the teams and all operations with minimal disruption to customers. By all indications, the transition has gone very well. The first quarter typically is the lowest quarter for cataract procedure volume and as a consequence has historically been the weakest for OMIDRIA sales, and we expect OMIDRIA revenues to continue to grow. As of March 31, 2022, we had $142.2 million of cash and investments on hand available to support ongoing operations. As previously noted, this is a decrease of $15 million from December 31, 2021. We also have $16.3 million of receivables, primarily OMIDRIA royalties related to the first quarter, which will be collected this month. Going forward OMIDRIA royalties will be paid monthly within 60 days of being earned. In addition, we have a $150 million at-the-market sales agreement, which we have not used. Also, under the terms of the Rayner transaction Omeros is eligible to receive a $200 million milestone, if before 2025, separate payment for OMIDRIA is secured for a continuous period of at least four years. One vehicle through which the $200 million milestone could be achieved is the enactment of the NOPAIN Act, which has been introduced in both chambers of commerce, and would provide separate payment for a renewable period of five years for non-opioid pain management drugs like OMIDRIA in ambulatory surgery centers or ASCs, as well as in hospital outpatient departments or HOPDs. Currently, CMS pays separately for OMIDRIA in the ASCs only. So the enactment of NOPAIN would expand separate payment to HOPDs as well. Efforts to advance the NOPAIN Act are being led nationally by voices for non-opioid choices and the legislation has been endorsed by more than 80 major medical societies patient advocacy groups and prevention and recovery organizations across the country. The legislation is good policy and enjoys strong bipartisan and bicameral support in Congress, with sponsors and cosponsors now numbering 48 Senators and 99 Representatives. Most recently, the 98 member new Democrat Coalition one of the largest and most influential caucuses in the House of Representatives has endorsed the NOPAIN Act, making it a key part of the coalition's legislative agenda for this summer. So wrapping up. With the divestiture of OMIDRIA we have a passive but substantial funding source to help finance Omeros' biotech portfolio, which is focused on immunology, including what many believe is the premier complement franchise in the industry and our novel immuno-oncology programs and on addiction. Having already discussed narsoplimab and our MASP-2 program, let's move now to OMS906, our antibody targeting MASP-3. MASP-3 is the key activator of the alternative pathway of complement. After having received scientific advice from the UKs health authority MHRA, we submitted our clinical trial application and remain on schedule to initiate a Phase Ib trial this summer. The trial will evaluate OMS906 in patients with Paroxysmal Nocturnal Hemoglobinuria or PNH, who have an unsatisfactory response to the C5 inhibitor ravulizumab. We previously completed a Phase I study in healthy subjects and results showed high-level suppression of alternative pathway activity, favorable pharmacokinetics and a good safety profile. While there can be no guarantees based on well-documented mechanism of action animal data and our Phase I results, we expect that OMS906 will be effective in PNH addressing both intravascular and extravascular hemolysis. We and others in the industry regard MASP-3 as the premier drug target in the alternative pathway and expect that OMS906 will have significant advantages over other agents on the market or in development to treat PNH. Those potential advantages include: one efficacy. Unlike C5 inhibitors OMS906 is expected to inhibit intravascular and to prevent extravascular red blood cell destruction. Two safety. Unlike other agents on the market for PNH OMS906 has been shown to leave intact the infection fighting ability of the adaptive immune response. Three dosing. Unlike Factor B and C3 inhibitors, which are currently dosed twice daily or twice weekly OMS906 is planned for once monthly to once quarterly administration. And finally, other drugs in the complement systems alternative pathway are what are referred to as acute phase reactants meaning that the blood concentration of those targets fluctuate substantially with inflammation. This can make dosing drugs that interact with those targets challenging leading to under or over dosing. To the best of our knowledge, MASP-3 is not an acute phase reactant meaning that the dosing of OMS906 can be more precise. We look forward to beginning dosing in PNH patients soon. Turning now to OMS527. Given resource constraints, we've prioritized our complement clinical programs over those of our phosphodiesterase 7 or PDE7 inhibitor program. We previously successfully completed a Phase I study of the lead molecule in this program. Discussions are underway regarding securing third-party funding for continued development of OMS527. We're also exploring the potential of our PDE7 inhibitors to improve dyskinesias in Parkinson's disease. More than 50% of Parkinson's patients develop L-DOPA induced dyskinesias following prolonged L-DOPA treatment. In collaboration with Emory University, we're evaluating our compounds in relevant primate Parkinson's disease models. We've previously shown that the PDE7 inhibitors improve outcomes in models of Parkinson's through modulation of the dopaminergic system. And we've established a broad intellectual property estate covering the use of PDE7 inhibitors for not only the treatment of addiction and compulsive disorders, but for the treatment of motor disorders, including Parkinson's disease. Finally, let's turn now to our immuno-oncology programs. We continue to focus on methods to improve the effectiveness of current cancer therapies. GPR174 is one of the 54 orphan G protein-coupled receptors or GPCRs that we have unlocked in our GPCR platform. And we continue to explore modulators of the GPR174 receptor as a means of significantly improving the tumor killing effects of current therapies, including adenosine pathway inhibitors and checkpoint inhibitors. Additionally, we're advancing research on technology that may improve the potency and durability of a top two T cell therapies. We validated our novel approach, which enforces memory phenotypes in cultured T cells through a previously unexplored pathway in an aggressive mouse tumor model and we're building a broad and exclusive intellectual property position around our platform. We believe that our novel approach has the potential to improve response rates for patients receiving either engineered or native T cell therapies for liquid or solid tumors and are continuing to explore the application of this technology to human CAR-T and adoptive T cell therapy systems. With that, I'll turn the call over to Mike Jacobsen our Chief Accounting Officer for a more detailed discussion of our first quarter financial results. Mike?