51 Obtaining and maintaining our paten t t protec t tion depe e nds d on compliance with i various procedural,l document submission, fee payment and othe t r requirements imposed by government paten t t agencies, and our paten t t protect t io t n couldl be reduced or elimi l na i ted for non-compliance with i these requirements. Periodic maintenance fees, renewal fees, annuity fees and various other government fees on patents and applications will be due to be paid to the USPTO and various government patent agencies outside of the United States over the lifet f ime of our owned or licensed patents and applications. The USPTO and various non-U.S. government agencies require compliance with several procedur d al, documentary, fee payment and other similar provisions during the patent application process. In some cases, an inadvertent laps a e can be cured by payment of a late fee or by other means in accordance with the applicable rules. Payment within these late fee windows may be employed in order to simplify the payment of these fees generally. There are situations, however, in which non-compliance can result in abandonment or laps a e of the patent or patent application, resulting in a partial or complete loss of patent rights in the relevant jurisdiction. In such an event, potential competitors might be able to enter the market with similar or identical products or technology, which could have a material adverse effe f ct on our business, financial condition, results of operations and prospects. In addition, while not relevant for tarcocimab a and KSI-501, if we rely on a different product, its development could involve the use of government funds, which can require additional compliance aspects to make certain all rights are transfer f red to or remain with us. Issued patentst may a be challe l nged or invalidat d ed t ,d and relativelyl recent changes in U.S. paten t t law have dimin i ished and may a furthe t r dimin i ish the value of pa f tentst in general. We rely on patentst to protec t t our products, t and any n dimi i ni i sh i ment in the scope or value of our paten t ts wouldl adverse r ly affe f ct our busine i ss. If we initiated legal proceedings against a third party to enforce a patent directed to our ABC Platform, product candidates or other technologies, the defendant could allege that such patent is invalid or unenfor f ceable. In patent litigation in the United States, defendant counterclaims alleging invalidity and unenfor f ceability are commonplace. Grounds for a validity challenge include alleged failures to meet any of several statut t ory r requirements, including obviousness, lack of novelty, lack of written description, or non-enablement. Grounds for an unenfor f ceability challenge include an allegation that someone connected with prosecution of the patent withheld material information from the USPTO with an intent to deceive the USPTO, or made a misleading statement, during prosecution. The filing of a legal proceeding could also result in the third party challenging the patent at the USPTO, such as in post-grant and inter partes review. Changes in either the patent laws or interpretation of the patent laws in the United States could increase the uncertainties and costs surrounding the prosecution of patent applications and the enforcement or defense of issued patents. For patent filings beginning in March 2013, the United States employs a first inventor to file system in which, assuming that other requirements for patentability are met, the first inventor to file a patent application will be entitled to the patent on an invention regardless of whether a third party was the first to invent the claimed invention. Under the current patent laws, a third party that files a patent application in the USPTO before us could therefor f e be awarded a patent covering an invention of ours even if we had made the invention before it was made by such third party. This will require us to be cognizant going forward of the time from invention to filing of a patent application. Since patent applications in the United States and most other countries are confid f ential for a period of time afte f r filing or until issuance, we cannot be certain that we were the first to either (1) file any patent application related to our ABC Platform, product candidates or other technologies or (2) invent any of the inventions claimed in our or our licensor’s patents or patent applications. Changes to U.S. patent laws since 2011 also include allowing third party subm u issions of prior art to the USPTO during patent prosecution and additional procedur d es for attacking the validity of a patent through USPTO administered post-grant proceedings, including re-examination, post-grant review, inter partes review, interference proceedings and derivation proceedings. Some of these changes apply to patents issued prior to 2011. These and equivalent proceedings in foreign jurisdictions (e.g., opposition proceedings) could result in the revocation of,f cancellation of or amendment to our patents in such a way that they no longer cover our ABC Platform, product candidates or other technologies. Because of a lower evidentiary r standard in USPTO proceedings compared to the evidentiary standards applied in United States federal courts that apply to actions seeking to invalidate a patent claim, a third party could potentially provide evidence in a USPTO proceeding sufficient for the USPTO to hold a claim invalid even though the same evidence would be insufficient to invalidate the claim if challenged in a district court action. Accordingly, a third party may attempt to use the USPTO procedur d es to invalidate our patent claims that would not otherwise have been invalidated if first challenged by the third party as a defendant in a district court action. As compared to intellectua t l property-reliant companies generally, the patent positions of companies in the development and commercialization of biologics and pharmaceuticals are particularly uncertain. U.S. Supr u eme Court rulings have narrowed the scope of patent protection availabl a e in certain circumstances and weakened the rights of patent owners in certain situations. These rulings have created uncertainty with respect to the validity and enforceability of patents, even once obtained. Depending on future actions by the U.S. Congress, the federal courts and the USPTO, the laws and regulations governing patents could change in unpredictabl a e ways that could have a material adverse effe f ct on our existing patent portfol f io and our ability to protect and enforce our intellectua t l property in the future.