Document

During the course of your relationship with Tourmaline Bio, Inc. (“Tourmaline”), you may receive material information that is not yet publicly available (“material nonpublic information”) about Tourmaline or other publicly traded companies that Tourmaline has business relationships with. Material nonpublic information may give you, or someone you pass that information on to, a leg up over others when deciding whether to buy, sell or otherwise transact in Tourmaline’s securities or the securities of another publicly traded company. This policy sets forth guidelines with respect to transactions in Tourmaline securities and in the securities of other applicable publicly traded companies, in each case by our employees, directors and consultants and the other persons or entities subject to this policy as described below.

This policy applies to all transactions in securities issued by Tourmaline, as well as derivative securities that are not issued by Tourmaline, such as exchange-traded put or call options or swaps relating to Tourmaline’s securities. Accordingly, for purposes of this policy, the terms “trade,” “trading” and “transactions” include not only purchases and sales of Tourmaline’s common stock in the public market but also any other purchases, sales, transfers or other acquisitions and dispositions of common or preferred equity, options, warrants and other securities (including debt securities) and other arrangements or transactions that affect economic exposure to changes in the prices of these securities.

This policy applies to you and all other employees, directors and consultants of Tourmaline and its subsidiaries. This policy also applies to members of your family who reside with you, any other persons with whom you share a household, any family members who do not live in your household but whose transactions in Tourmaline’s securities are directed by you or are subject to your influence or control and any other individuals or entities whose transactions in securities you influence, direct or control (including, e.g., a venture or other investment fund, if you influence, direct or control transactions by the fund). However, this policy does not apply to any entity that invests in Tourmaline’s securities (e.g., a venture or other investment fund) if, and only if, such entity has established its own insider trading controls and procedures in compliance with applicable securities laws with respect to trading in Tourmaline’s securities. The foregoing persons who are deemed subject to this policy are referred to in this policy as “Related Persons.” You are responsible for making sure that your Related Persons comply with this policy.

•disclose material nonpublic information to persons within Tourmaline whose jobs do not require them to have that information, or outside of Tourmaline to other persons, such as family, friends, business associates and investors, unless the disclosure is made in accordance with Tourmaline’s policies regarding the protection or authorized external disclosure of information regarding Tourmaline; or

The prohibition against insider trading is absolute. It applies even if the decision to trade is not based on such material nonpublic information. It also applies to transactions that may be necessary or justifiable for independent reasons (such as the need to raise money for an emergency expenditure) and also to very small transactions. All that matters is whether you are aware of any material nonpublic information relating to Tourmaline at the time of the transaction.

The U.S. federal securities laws do not recognize any mitigating circumstances to insider trading. In addition, even the appearance of an improper transaction must be avoided to preserve Tourmaline’s reputation for adhering to the highest standards of conduct. In some circumstances, you may need to forgo a planned transaction even if you planned it before becoming aware of the material nonpublic information. So, even if you believe you may suffer an economic loss or sacrifice an anticipated profit by waiting to trade, you must wait.

It is also important to note that the laws prohibiting insider trading are not limited to trading by the insider alone; advising others to trade on the basis of material nonpublic information is illegal and squarely prohibited by this policy. Liability in such cases can extend both to the “tippee”—the person to whom the insider disclosed material nonpublic information—and to the “tipper,” the insider himself or herself. In such cases, you can be held liable for your own transactions, as well as the transactions by a tippee and even the transactions of a tippee’s tippee. For these and other reasons, it is the policy of Tourmaline that no employee, director or consultant of Tourmaline (or any other person or entity subject to this policy) may either (a) recommend to another person or entity that they buy, hold or sell Tourmaline’s securities at any time or (b) disclose material nonpublic information to persons within Tourmaline whose jobs do not require them to have that information, or outside of Tourmaline to other persons (unless the disclosure is made in accordance with Tourmaline’s policies

In addition, it is the policy of Tourmaline that no person subject to this policy who, in the course of his or her relationship with Tourmaline, learns of any confidential information that is material to another publicly traded company with which Tourmaline does business, including a supplier, partner or collaborator of Tourmaline, may trade in that other company’s securities until the information becomes public or is no longer material to that other company.

It is not always easy to figure out whether you are aware of material nonpublic information. But there is one important factor to determine whether nonpublic information you know about a public company is material: whether the information could be expected to affect the market price of that company’s securities or to be considered important by investors who are considering trading that company’s securities. If the information makes you want to trade, it would probably have the same effect on others. Keep in mind that both positive and negative information can be material.

There is no bright-line standard for assessing materiality; rather, materiality is based on an assessment of all of the facts and circumstances, and is often evaluated by relevant enforcement authorities with the benefit of hindsight. Depending on the specific details, the following items may be considered material nonpublic information until publicly disclosed within the meaning of this policy. There may be other types of information that would qualify as material information as well; use this list merely as a non-exhaustive guide:

The prohibition on trading when you have material nonpublic information lifts once that information becomes publicly disseminated. But for information to be considered publicly disseminated, it must be widely disseminated through a press release, a filing with the Securities and Exchange Commission (the “SEC”), or other widely disseminated announcement. Once information is publicly disseminated, it is still necessary to afford the investing public with sufficient time to absorb the information. Generally speaking, information will be considered publicly disseminated for purposes of this policy only after two full trading days have elapsed since the information was publicly disclosed. For example, if we announce material nonpublic information before trading begins on Wednesday, then you may execute a transaction in our securities on Friday; if we announce material nonpublic information after trading ends on Wednesday, then you may execute a transaction in our securities on Monday. Depending on the particular circumstances, Tourmaline may determine that a longer or shorter waiting period should apply to the release of specific material nonpublic information.

Because our workplace culture tends to be open, odds are that the vast majority of our employees, directors and consultants will possess material nonpublic information at certain points during the year. To minimize even the appearance of insider trading among our employees, directors and consultants we have established “quarterly trading blackout periods” during which Tourmaline employees, directors, consultants and their Related Persons—regardless of whether they are aware of material nonpublic information or not—may not conduct any trades in Tourmaline securities. That means that, except as described in this policy, all Tourmaline employees, directors, consultants and their Related Persons will be able to trade in Tourmaline securities only during limited open trading window periods that generally will begin after two full trading days have elapsed since the public dissemination of Tourmaline’s annual or quarterly financial results and end at the beginning of the next quarterly trading blackout period. Of course, even during an open trading window period, you may not (unless an exception applies) conduct any trades in Tourmaline securities if you are otherwise in possession of material nonpublic information.

For purposes of this policy, each “quarterly trading blackout period” will generally begin at the end of each fiscal quarter and end after two full trading days have elapsed since the public dissemination of Tourmaline’s financial results for that quarter. Please note that the quarterly trading blackout period may commence early or may be extended if, in the judgment of the Chief Executive Officer and Chief Business Officer and General Counsel, there exists undisclosed information that would make trades by Tourmaline employees, directors and consultants inappropriate. It is important to note that the fact that the quarterly trading blackout period has commenced early or has been extended should be considered material nonpublic information that should not be communicated to any other person.

A Tourmaline employee, director or consultant who believes that special circumstances require him or her to trade during a quarterly trading blackout period should consult the General Counsel. Permission to trade during a quarterly trading blackout period will be granted only where the circumstances are extenuating, the General Counsel concludes that the person is not in fact aware of any material nonpublic information relating to Tourmaline or its securities, and there appears to be no significant risk that the trade may subsequently be questioned.

From time to time, an event may occur that is material to Tourmaline and is known by only a few directors, officers and/or employees. So long as the event remains material and nonpublic, the persons designated by the Chief Executive Officer and Chief Business Officer and General Counsel may not trade in Tourmaline’s securities. In that situation, Tourmaline will notify the designated individuals that neither they nor their Related Persons may trade in the Tourmaline’s securities. The existence of an event-specific trading blackout should also be considered material nonpublic information and should not be communicated to any other person. Even if you have not been designated as a person who should not trade due to an event-specific trading blackout, you should not trade while aware of material nonpublic information. Exceptions will not be granted during an event-specific trading blackout.

Option Exercises. This policy does not apply to the exercise of options granted under Tourmaline’s equity compensation plans for cash or, where permitted under the option, by a net exercise transaction with the Company or by delivery to Tourmaline of already-owned Tourmaline stock. This policy does, however, apply to any sale of stock as part of a broker-assisted cashless exercise or any other market sale, whether or not for the purpose of generating the cash needed to pay the exercise price or pay taxes.

Tax Withholding Transactions. This policy does not apply to the surrender of shares directly to Tourmaline to satisfy tax withholding obligations as a result of the issuance of shares upon vesting or exercise of restricted stock units, options or other equity awards granted under Tourmaline’s equity compensation plans. Of course, any market sale of the stock received upon exercise or vesting of any such equity awards remains subject to all provisions of this policy whether or not for the purpose of generating the cash needed to pay the exercise price or pay taxes.

10b5-1 Automatic Trading Programs. Under Rule 10b5-1 of the Securities Exchange Act of 1934, as amended (“Exchange Act”), and as permitted by Tourmaline, employees, directors and consultants may establish a trading plan under which a broker is instructed to buy and sell Tourmaline securities based on pre-determined criteria (a “Trading Plan”). So long as a Trading Plan is properly established, purchases and sales of Tourmaline securities pursuant to that Trading Plan are not subject to this policy. To be properly established, an employee’s or director’s Trading Plan must be established in compliance with the requirements of Rule 10b5-1 of the Exchange Act and any applicable 10b5-1 trading plan guidelines of Tourmaline at a time when they were unaware of any material nonpublic information relating Tourmaline and when Tourmaline was not otherwise in a trading blackout period. Moreover, all Trading Plans must be reviewed and approved by Tourmaline before being established to confirm that the Trading Plan complies with all pertinent company policies and applicable securities laws.

Gifts. This policy does not apply to bona fide gifts of Tourmaline securities that have been pre-cleared by Tourmaline’s General Counsel or his or her designee. Whether a gift is truly bona fide will depend on the facts and circumstances surrounding each gift. Pre-clearance must be obtained at least two business days in advance of the proposed gift, and pre-cleared gifts not completed within two business days will require new pre-clearance. Tourmaline may choose to shorten this period.

401(k) Plan. This policy does not apply to purchases of Tourmaline’s securities in Tourmaline’s 401(k) plan resulting from your periodic contribution of money to the plan pursuant to your payroll deduction election. This policy does apply, however, to certain elections you may make under the 401(k) plan, including: (a) an election to increase or decrease the percentage of your periodic contributions that will be allocated to the Tourmaline stock fund; (b) an election to make an intra-plan transfer of an existing account balance into or out of the Tourmaline stock fund; (c) an election to borrow money against your 401(k) plan account if the loan will result in a liquidation of some or all of your Tourmaline stock fund balance; and (d) an election to pre-pay a plan loan if the pre-payment will result in allocation of loan proceeds to the Tourmaline stock fund.

Inherently Speculative Transactions. No Tourmaline employee, director or consultant may engage in short sales, transactions in put options, call options or other derivative securities on an exchange or in any other organized market, or in any other inherently speculative transactions with respect to Tourmaline’s stock.

Hedging Transactions. Hedging or monetization transactions can be accomplished through a number of possible mechanisms, including through the use of financial instruments such as prepaid variable forwards, equity swaps, collars and exchange funds. Such hedging transactions may permit a Tourmaline employee, director or consultant to continue to own Tourmaline’s securities obtained through employee benefit plans or otherwise, but without the full risks and rewards of ownership. When that occurs, the Tourmaline employee, director or consultant may no longer have the same objectives as Tourmaline’s other stockholders. Therefore, Tourmaline employees, directors and consultants are prohibited from engaging in any such transactions.

Margin Accounts and Pledged Securities. Securities held in a margin account as collateral for a margin loan may be sold by the broker without the customer’s consent if the customer fails to meet a margin call. Similarly, securities pledged (or hypothecated) as collateral for a loan may be sold in foreclosure if the borrower defaults on the loan. Because a margin sale or foreclosure sale may occur at a time when the pledgor is aware of material nonpublic information or otherwise is not permitted to trade in Tourmaline’s securities, Tourmaline employee, director and consultants are prohibited from holding Tourmaline’s securities in a margin account or otherwise pledging Tourmaline’s securities as collateral for a loan.

Standing and Limit Orders. Standing and limit orders (except standing and limit orders under approved Trading Plans, as discussed above) create heightened risks for insider trading violations similar to the use of margin accounts. There is no control over the timing of purchases or sales that result from standing instructions to a broker, and as a result the broker could execute a transaction when a Tourmaline employee, director or consultant is in possession of material nonpublic information. Tourmaline therefore discourages placing standing or limit orders on Tourmaline’s securities. If a person subject to this policy determines that they must use a standing order or limit order (other than under an approved Trading Plan as discussed above), the order should be limited to short duration and the person using such standing order or limit order is required to cancel such instructions immediately in the event restrictions are imposed on their ability to trade pursuant to the “Quarterly Trading Blackouts” and “Event-Specific Trading Blackouts” provisions above.

Even during an open trading window, employees, including officers, and directors may not engage in any transaction in Tourmaline’s securities without first obtaining pre-clearance of the transaction from Tourmaline’s General Counsel or his or her designee at least two business days in advance of the proposed transaction. The General Counsel or his or her designee will then determine whether the transaction may proceed and, if so, will direct the Section 16 Compliance Officer (as identified in Tourmaline’s Section 16 Compliance Program) to help comply with any required reporting requirements under Section 16(a) of the Exchange Act. Pre-

Persons subject to pre-clearance must also give advance notice of their plans to exercise an outstanding stock option to the Section 16 Compliance Officer or General Counsel. Once any transaction takes place, the employee, officer or director must immediately notify the Section 16 Compliance Officer and any other individuals identified under the heading “Notification of Execution of Transaction” in Tourmaline’s Section 16 Compliance Program so that Tourmaline may assist in any Section 16 reporting obligations.

Officers and directors subject to the reporting obligations under Section 16 of the Exchange Act should take care to avoid short-swing transactions (within the meaning of Section 16(b) of the Exchange Act) and the restrictions on sales by control persons (Rule 144 under the Securities Act of 1933, as amended), and should file all appropriate Section 16(a) reports (Forms 3, 4 and 5), which are described in Tourmaline’s Section 16 Compliance Program, and any notices of sale required by Rule 144.

No director or executive officer of Tourmaline may, directly or indirectly, purchase, sell or otherwise transfer any equity security of Tourmaline (other than an exempt security) during any “blackout period’’ (as defined in Regulation BTR under the Exchange Act) if a director or executive officer acquires or previously acquired such equity security in connection with his or her service or employment as a director or executive officer. This prohibition does not apply to any transactions that are specifically exempted, including but not limited to, purchases or sales of Tourmaline’s securities made pursuant to, and in compliance with, a Trading Plan; compensatory grants or awards of equity securities pursuant to a plan that, by its terms, permits executive officers and directors to receive automatic grants or awards and specifies the terms of the grants and awards; or acquisitions or dispositions of equity securities involving a bona fide gift or by will or the laws of descent or pursuant to a domestic relations order. Tourmaline will notify each director and executive officer of any blackout periods in accordance with the provisions of Regulation BTR. Because Regulation BTR is very complex, no director or executive officer of Tourmaline should engage in any transactions in Tourmaline’s securities, even if believed to be exempt from Regulation BTR, without first consulting with the General Counsel.

This policy continues to apply to your transactions in Tourmaline’s securities and the securities of other applicable public companies as more specifically set forth in this policy, even after your relationship with Tourmaline has ended. If you are aware of material nonpublic information when your relationship with Tourmaline ends, you may not trade Tourmaline’s securities or the securities of other applicable publicly traded companies until the material nonpublic information has been publicly disseminated or is no longer material. Further, if you leave Tourmaline during a trading blackout period, then you may not trade Tourmaline’s

Persons subject to this policy have ethical and legal obligations to maintain the confidentiality of information about Tourmaline and to not engage in transactions in Tourmaline’s securities or the securities of other applicable public companies while aware of material nonpublic information, as more specifically set forth in this policy. Each individual is responsible for making sure that he or she complies with this policy, and that any family member, household member or other person or entity whose transactions are subject to this policy, as discussed under the heading “Persons Subject to this Policy” above, also comply with this policy. In all cases, the responsibility for determining whether an individual is aware of material nonpublic information rests with that individual, and any action on the part of Tourmaline or any employee or director of Tourmaline pursuant to this policy (or otherwise) does not in any way constitute legal advice or insulate an individual from liability under applicable securities laws. You could be subject to severe legal penalties and disciplinary action by Tourmaline for any conduct prohibited by this policy or applicable securities laws. See “Penalties” below.

Anyone who engages in insider trading or otherwise violates this policy may be subject to both civil liability and criminal penalties. Violators also risk disciplinary action by Tourmaline, including termination of employment. Anyone who has questions about this policy should contact their own attorney or Tourmaline’s General Counsel, at [*****]. Please also see Frequently Asked Questions, which are attached as Exhibit A.

Tourmaline is committed to continuously reviewing and updating its policies and procedures. Tourmaline therefore reserves the right to amend, alter or terminate this policy at any time and for any reason. A current copy of the Tourmaline’s policies regarding insider trading may be obtained by contacting the Section 16 Compliance Officer at [*****].