ArriVent BioPharma, Inc.

From time to time, we may be subject to legal proceedings. On July 22, 2026, we received a notice from the United States Patent and Trademark Office (the “USPTO”) that the USPTO has granted a request for ex parte reexamination (the “Request”) of U.S. Reissue Patent No. 48,687 (the “RE ’687 Patent”). The RE ’687 Patent is one of several U.S. patents covering firmonertinib and claims certain compounds or pharmaceutically acceptable salts thereof, including firmonertinib and pharmaceutically acceptable salts thereof. The Request was submitted by an anonymous third party and alleges that the claims of the RE ’687 Patent are obvious over asserted prior art and are therefore unpatentable. We believe the Request lacks merit and will vigorously defend the patentability of the claims of the RE ’687 Patent during ex parte reexamination. On October 19, 2026, we received a notice from the USPTO that the USPTO has closed prosecution on the merits of the ex parte reexamination and indicating that the USPTO intends to issue a reexamination certificate confirming all claims of the RE ’687 Patent subject to ex parte reexamination. We cannot predict the outcome of the ex parte reexamination proceeding, which could result in all or some of the claims being confirmed as patentable, narrowed, or cancelled as deemed unpatentable. Our other United States patents and pending patent applications covering firmonertinib are not subject to the ex parte reexamination. Regardless of outcome, litigation can have an adverse impact on us because of defense and settlement costs, diversion of management resources, and other factors.

Other than the foregoing, we are not currently a party to or aware of any proceedings that we believe will have, individually or in the aggregate, a material adverse effect on our business, financial condition or results of operations.