28 Our inability to enroll a sufficient number of patients for our clinical trials could result in significant delays or may require us to abandon one or more clinical trials altogether. Enrollment delays in our clinical trials may result in increased development costs for our product candidates, delay or halt the development of and approval processes for our product candidates and jeopardize our ability to commence sales of and generate revenues from our product candidates, which may harm our business and results of operation. Our clin l ical trials may a fail to demonstratet substantia t l evidence of the durabili i ty i ,y effi f cacy and safe a ty of our product candid d at d es t ,s which wouldl prevent,t delay a or limiti the scope of regu e latory approval and commercializ l atio t n. Before obtaining regulatory r approvals for the commercial sale of any of our product candidates, we must demonstrate through lengthy, complex and expensive preclinical studi t es and clinical trials that our product candidates are both safe and effe f ctive for use in each target indication. For those product candidates that are subj u ect to regulation as biological drug r products, we will need to demonstrate that they are safe, pure, and potent for use in their target indications. Each product candidate must demonstrate an adequate risk versus benefit profil f e in its intended patient population and for its intended use. This is especially true r for anti-VEGF biologic agents, where Lucentis, Eylea and Avastin are establ a ished products with accepted safety profil f es. Clinical testing is expensive and can take many years to complete, and its outcome is inherently uncertain. Failure can occur at any time during the clinical trial process. The results of preclinical studi t es of our product candidates may not be predictive of the results of early-stage or later-stage clinical trials, and results of early clinical trials of our product candidates may not be predictive of the results of later-stage clinical trials. The results of clinical trials in one set of patients or disease indications may not be predictive of those obtained in another. In some instances, there can be significant variability in safety, effi f cacy or durability results between different clinical trials of the same product candidate due to numerous factors, including changes in trial procedur d es set forth in protocols, differences in the size and type of the patient populations, changes in and adherence to the dosing regimen and other clinical trial protocols and the rate of dropout among clinical trial participants. Product candidates in later stages of clinical trials may fail to show the desired safety, effi f cacy and durability profile f despite having progressed through preclinical studi t es and initial clinical trials. A number of companies in the biopharmaceutical industry r have suffer f ed significant setbacks in advanced clinical trials due to lack of effi f cacy or unacceptabl a e safety issues, notwithstanding promising results in earlier trials. For example, in our Phase 2b/3 clinical trial evaluating the effi f cacy, durability and safety of tarcocimab a in treatment-naïve subj u ects with neovascular wet AMD and in our Phase 3 GLEAM and GLIMMER studi t es, tarcocimab a did not meet the primary r effi f cacy endpoint of showing non-inferior visual acuity gains. Most product candidates that begin clinical trials are never approved by regulatory r authorities for commercialization. We may be unabl a e to design and execute clinical trials that suppor u t marketing approval. We cannot be certain that our planned clinical trials or any other future clinical trials will be successful f . Additionally, any safety concerns observed in any one of our clinical trials in our targeted indications could limit the prospects for regulatory r approval of our product candidates in those and other indications, which could have a material adverse effe f ct on our business, financial condition and results of operations. In addition, even if such clinical trials are successful f ly completed, we cannot guarantee that the FDA or foreign regulatory r authorities will interpret the results as we do, and more trials or trials of a different design could be required before we subm u it our product candidates for approval. To the extent that the results of trials are not satisfactory r to the FDA or foreign regulatory r authorities for suppor u t of a marketing application, we may be required to expend significant resources, which may not be availabl a e to us, to conduct additional trials in suppor u t of potential approval of our product candidates. Even if regulatory r approval is secured for any of our product candidates, the terms of such approval may limit the scope and use of our product candidate, which may also limit its commercial potential. Even if trial results are successful f at the primary r endpoint, clinical trial results may be different or worse in the extended treatment periods following the primary endpoint, and such data may negatively impact perceptions by regulatory r authorities, the clinical community or commercial payors of the benefits of our product candidates. We may a not be successful f in our effo f rtst to contin t ue to create a pipe i line i of pr f oduct candid d at d es t or to develop o commercially successful f products. t If we fail to successful f ly l iden d tify i and develop l additi i onal product candid d at d es t ,s our commercial opportunity i may a be limited t .d Our research methodology may be unsuccessful in identifyi f ng potential product candidates, or our potential product candidates may be shown to have harmful side effe f cts or may have other characteristics that may make them unmarketabl a e or unlikely to receive marketing approval. Identifyi f ng, developing, obtaining regulatory r approval and commercializing additional product candidates for the treatment of retinal diseases will require subs u tantial additional funding and is prone to the risks of failure inherent in drug r development. If we are unabl a e to successful f ly identify, f acquire, develop and commercialize additional product candidates, our commercial opportunity may be limited.