Exhibit 4.3

DESCRIPTION OF REGISTRANT’S SECURITIES

REGISTERED PURSUANT TO SECTION 12 OF

THE SECURITIES EXCHANGE ACT OF 1934, AS AMENDED

ArriVent Biopharma, Inc. has one class of securities registered under Section 12 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”): our common stock, par value $0.0001 per share. Unless the context otherwise requires, all references to “we”, “us”, the “Company”, or “ArriVent” in this Exhibit 4.3 refer to ArriVent Biopharma, Inc.

DESCRIPTION OF COMMON STOCK

We are authorized to issue 200,000,000 shares of common stock, par value $0.0001 per share, and 10,000,000 shares of preferred stock, par value $0.0001 per share.

The following description of our common stock and provisions of our amended and restated certificate of incorporation and amended and restated by-laws are summaries of material terms and provisions and are qualified by reference to our amended and restated certificate of incorporation and amended and restated by-laws, copies of which have been filed with the SEC as exhibits to the Annual Report on Form 10-K. The descriptions of our common stock reflect the content of the amended and restated certificate of incorporation and amended and restated by-laws.

General

Holders of our common stock are entitled to receive dividends ratably, if any, as may be declared by our board of directors out of legally available funds, subject to any preferential dividend rights of any preferred stock then outstanding. Upon our dissolution, liquidation or winding up, holders of our common stock are entitled to share ratably in our net assets legally available after the payment of all our debts and other liabilities, subject to the preferential rights of any preferred stock then outstanding. Holders of our common stock have no preemptive, subscription, redemption or conversion rights. Our outstanding shares of common stock are validly issued, fully paid and nonassessable. The rights, preferences, and privileges of holders of common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock that we may designate and issue in the future. Except as described under the “— Anti-Takeover Effects of Delaware Law, Our Amended and Restated Certificate of Incorporation and Our Amended and Restated By-Laws” section below, a majority vote of the holders of common stock is generally required to take action under our amended and restated certificate of incorporation and amended and restated by-laws.

Registration Rights

We are party to the Amended and Restated Investors’ Rights Agreement, dated December 16, 2022 (the “Investors’ Rights Agreement”), pursuant to which holders of registrable shares can demand that we file a registration statement or request that their shares be included on a registration statement that we are otherwise filing, in either case, registering the resale of their shares of common stock. These registration rights are subject to conditions and limitations, including the right, in certain circumstances, of the underwriters of an offering to limit the number of shares included in such registration and our right, in certain circumstances, not to effect a registration upon demand of the holders of registrable shares within 30 days preceding our good faith estimate of the date of filing of, and 90 days following the effective date of any registration statement that we file covering a firm commitment underwritten public offering in which the holders of registrable shares were entitled to join and in which we effectively registered all registrable shares that were requested to be registered.

Demand Registration Rights

Following the date that is 180 days after the date of our initial public offering, the holders of a majority of registrable securities then outstanding under the Investors’ Rights Agreement may require us to file a registration statement under the Securities Act of 1933, as amended (the “Securities Act”) on a registration statement on Form S-1 at our expense, subject to certain exceptions, with an anticipated aggregate offering price, net of the offering expenses, of more than $20.0 million, in which case we will be required to effect the registration as soon as practicable, and in any event within 60 days. We are required to effect only two demand registrations pursuant to this provision of the Investors’ Rights Agreement. Any time after we are eligible to use a registration statement on

Form S-3, the holders of at least 10% of our registrable securities under the Investors’ Rights Agreement may require us to file a registration statement on Form S-3 at our expense, subject to certain exceptions, with respect to the then outstanding registrable securities of such holders having an anticipated aggregate offering price, net of the offering expenses, of at least $5.0 million, in which case we will be required to effect the registration as soon as practicable, and in any event within 45 days. If we determine that it would be detrimental to us and our stockholders to effect a requested registration, we may postpone each such registration for a period of up to 60 days; provided that we may neither invoke this right more than once in any 12-month period nor effect a registration for our own account or any other stockholder during such 60 day period. The foregoing demand registration rights are subject to a number of additional exceptions and limitations.

Piggyback Registration Rights

If we propose to file a registration statement under the Securities Act for the purposes of a public offering of our securities, including, but not limited to, registration statements relating to a secondary offering of our securities but excluding (i) a registration statement relating to the sale or grant of securities to employees pursuant to a stock option, stock purchase, equity incentive or similar plan; (ii) with respect to any corporate reorganization or transaction under Rule 145 of the Securities Act; (iii) a registration on any form that does not include substantially the same information as would be required to be included in a registration statement covering the sale of the registrable securities; or (iv) a registration in which the only common stock being registered is common stock issuable upon conversion of debt securities that are also being registered, the holders of registrable securities are entitled to receive notice of such registration and to request that we include their registrable securities for resale in the registration statement. The underwriters of the offering will have the right to limit the number of shares to be included in such registration. The foregoing piggyback registration rights are subject to a number of additional exceptions and limitations.

Expiration of Registration Rights

The registration rights will terminate upon the earliest to occur of (i) the closing of certain liquidation events and (ii) such time after closing of our initial public offering as Rule 144 or another similar exemption under the Securities Act is available for the sale of all such holders’ registrable securities without limitation, during a three-month period without registration.

Indemnification

The Investors’ Rights Agreement contains customary cross-indemnification provisions pursuant to which we are obligated to indemnify the selling stockholders, in the event of misstatements or omissions in the registration statement attributable to us, and they are obligated to indemnify us for misstatements or omissions attributable to them.

Nasdaq Global Market Listing

Our common stock is listed on The Nasdaq Global Market under the trading symbol “AVBP.”

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A.

CERTAIN PROVISIONS OF DELAWARE LAW AND OF THE COMPANY’S CERTIFICATE OF INCORPORATION AND BYLAWS

Anti-Takeover Effects of Delaware Law, Our Amended and Restated Certificate of Incorporation and Our Amended and Restated By-Laws

Some provisions of Delaware law, our amended and restated certificate of incorporation and our amended and restated bylaws could make the following transactions more difficult: an acquisition of us by means of a tender offer; an acquisition of us by means of a proxy contest or otherwise; or the removal of our incumbent officers and directors. It is possible that these provisions could make it more difficult to accomplish or could deter transactions that stockholders

may otherwise consider to be in their best interest or in our best interests, including transactions which provide for payment of a premium over the market price for our shares.

These provisions, summarized below, are intended to discourage coercive takeover practices and inadequate takeover bids. These provisions are also designed to encourage persons seeking to acquire control of us to first negotiate with our board of directors. We believe that the benefits of the increased protection of our potential ability to negotiate with the proponent of an unfriendly or unsolicited proposal to acquire or restructure us outweigh the disadvantages of discouraging these proposals because negotiation of these proposals could result in an improvement of their terms.

Board Composition and Filling Vacancies

In accordance with our amended and restated certificate of incorporation, our board of directors is divided into three classes serving three-year terms, with one class being elected each year. Our amended and restated certificate of incorporation also provides that directors may be removed only for cause and then only by the affirmative vote of the holders of seventy-five percent of the shares then entitled to vote at an election of directors. Furthermore, any vacancy on our board of directors, however occurring, including a vacancy resulting from an increase in the size of our board of directors, will only be able to be filled by the affirmative vote of a majority of our directors then in office, even if less than a quorum.

No Written Consent of Stockholders

Our amended and restated certificate of incorporation provides that all stockholder actions are required to be taken by a vote of the stockholders at an annual or special meeting, and that stockholders may not take any action by written consent in lieu of a meeting.

Meetings of Stockholders

Our amended and restated by-laws provide that only a majority of the members of our board of directors then in office may call special meetings of stockholders and only those matters set forth in the notice of the special meeting may be considered or acted upon at a special meeting of stockholders. Our amended and restated by-laws limit the business that may be conducted at an annual meeting of stockholders to those matters properly brought before the meeting.

Advance Notice Requirements

Our amended and restated bylaws establish advance notice procedures with regard to stockholder proposals relating to the nomination of candidates for election as directors or new business to be brought before meetings of our stockholders. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate secretary prior to the meeting at which the action is to be taken.

Generally, to be timely, notice must be received at our principal executive offices not less than 90 days or more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. The notice must contain certain information specified in our amended and restated bylaws. These provisions may have the effect of precluding the conduct of certain business at a meeting if the proper procedures are not followed. These provisions may also discourage or deter a potential acquirer from conducting a solicitation of proxies to elect the acquirer’s own slate of directors or otherwise attempting to obtain control of our Company.

Amendment to Bylaws and Certificate of Incorporation

As required by the Delaware General Corporation Law, any amendment of our amended and restated certificate of incorporation must first be approved by a majority of our board of directors and, if required by law or our amended and restated certificate of incorporation, thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment, and a majority of the outstanding shares of each class entitled to vote thereon as a class, except that the amendment of the provisions relating to stockholder action, directors, limitation of liability, exclusive jurisdiction of

Delaware Courts and the amendment of our amended and restated by-laws and amended and restated certificate of incorporation must be approved by not less than seventy-five percent of the outstanding shares entitled to vote on the amendment, and not less than seventy-five percent of the outstanding shares of each class entitled to vote thereon as a class. Our amended and restated by-laws may be amended by the affirmative vote of a majority of the directors then in office, subject to any limitations set forth in the amended and restated by-laws; and may also be amended by the affirmative vote of at least seventy-five percent of the outstanding shares entitled to vote on the amendment, or, if the board of directors recommends that the stockholders approve the amendment, by the affirmative vote of the majority of the outstanding shares entitled to vote on the amendment.

Section 203 of the Delaware General Corporation Law

We are subject to the provisions of Section 203 of the Delaware General Corporation Law. In general, Section 203 prohibits a publicly-held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a three-year period following the time that this stockholder becomes an interested stockholder, unless the business combination is approved in a prescribed manner. A “business combination” includes, among other things, a merger, asset or stock sale or other transaction resulting in a financial benefit to the interested stockholder. An “interested stockholder” is a person who, together with affiliates and associates, owns, or did own within three years prior to the determination of interested stockholder status, 15% or more of the corporation’s voting stock.

Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions:

· before the stockholder became interested, the board of directors approved either the business combination or the transaction that resulted in the stockholder becoming an interested stockholder;

· upon closing of the transaction that resulted in the stockholder becoming an interested stockholder, the interested stockholder owned at least 85% of the voting stock of the corporation outstanding at the time the transaction commenced, excluding for purposes of determining the voting stock outstanding, shares owned by persons who are directors and also officers, and employee stock plans, in some instances; or

· at or after the time the stockholder became interested, the business combination was approved by the board of directors of the corporation and authorized at an annual or special meeting of the stockholders by the affirmative vote of at least two-thirds of the outstanding voting stock that is not owned by the interested stockholder.

A Delaware corporation may “opt out” of these provisions with an express provision in its original certificate of incorporation or an express provision in its amended and restated certificate of incorporation or amended and restated by-laws resulting from a stockholders’ amendment approved by at least a majority of the outstanding voting shares. We have not opted out of these provisions. As a result, mergers or other takeover or change in control attempts of us may be discouraged or prevented.

Exclusive Jurisdiction of Certain Actions

Our amended and restated certificate of incorporation provides that, unless we consent in writing to the selection of an alternative forum, the Court of Chancery of the State of Delaware (or, if the Court of Chancery does not have jurisdiction, the federal district court for the District of Delaware or other state courts of the State of Delaware) will be the sole and exclusive forum for any state law claim for: (1) any derivative action or proceeding brought on our behalf; (2) any action or proceeding asserting a claim of breach of a fiduciary duty or other wrongdoing by any of our directors, officers, employees or agents to us or our stockholders; (3) any action or proceeding asserting a claim against us arising pursuant to any provision of the Delaware General Corporation Law or our certificate of incorporation or bylaws (in each case, as they may be amended from time to time); (4) any action or proceeding to interpret, apply, enforce or determine the validity of our amended and restated certificate of incorporation or bylaws; (5) any action or proceeding as to which the Delaware General Corporation Law confers jurisdiction to the Court of Chancery of the State of Delaware; or (6) any action asserting a claim against us or any of our directors, officers or employees that is governed by the internal affairs doctrine. The choice of forum provision does not apply to any actions arising under the Exchange Act. Our amended and restated certificate of incorporation further provides that, unless we consent in writing to an alternative forum, the United States District Court for the District of Pennsylvania will be the exclusive forum for

resolving any complaint asserting a cause of action arising under the Securities Act. We have chosen the United States District Court for the District of Pennsylvania as the exclusive forum for such Securities Act causes of action because our principal executive offices are located in Newtown Square, Pennsylvania. In addition, our amended and restated certificate of incorporation provides that any person or entity purchasing or otherwise acquiring any interest in shares of our common stock is deemed to have notice of and consented to the foregoing provisions.

The choice of forum provisions may limit a stockholder’s ability to bring a claim in a judicial forum that it finds favorable for disputes with us or any of our current or former director, officer, other employee, agent, or stockholder to the Company, which may discourage such claims against us or any of our current or former director, officer, other employee, agent, or stockholder to the Company and result in increased costs for investors to bring a claim. Alternatively, if a court were to find the choice of forum provisions contained in our amended and restated certificate of incorporation to be inapplicable or unenforceable in an action, we may incur additional costs associated with resolving such action in other jurisdictions, which could harm our business, results of operations and financial condition.