Bain Capital discloses Kailera preferred stake

Kailera Therapeutics, Inc. reported that Bain Capital–affiliated entities are indirect ten percent owners through holdings of the company’s Series B Preferred Stock.

Rhea-AI Filing Summary

Kailera Therapeutics, Inc. reported that Bain Capital–affiliated entities are indirect ten percent owners through holdings of the company’s Series B Preferred Stock. The filing shows 17,857,143 shares of Series B Preferred Stock, which are convertible into an equal number of common shares on a 1:1 basis.

These preferred shares are held directly by BCPE Perseus Investor, LP, while related Bain Capital entities are positioned upstream as general partners or managing members and may be deemed to share voting and dispositive power. The Bain entities each disclaim beneficial ownership beyond their pecuniary interest in these securities.

Insider Trade Summary

1 transaction reported

Mixed 1 txn

Insider BAIN CAPITAL INVESTORS LLC, Bain Capital XIV General Partner, LLC, Bain Capital Fund XIV, L.P., BCPE Perseus Investor GP, LLC, BCPE Perseus Investor, LP

Role 10% Owner | 10% Owner | 10% Owner | 10% Owner | 10% Owner

Type	Security	Shares	Price	Value
holding	Series B Preferred Stock	--	--	--

Holdings After Transaction: Series B Preferred Stock — 17,857,143 contracts (Indirect, See footnotes)

Footnotes (3)

1. F1. Each share of the Issuer's Series B Preferred Stock is convertible, at the option of the holder, into shares of the Issuer's Common Stock on a 1:1 basis and will automatically convert upon the closing of the Issuer's initial public offering. These securities have no expiration date.
2. F2. Represents shares of the Issuer's Series B Preferred Stock held directly by BCPE Perseus Investor, LP ("BCPE Perseus").
3. F3. Bain Investors, LLC ("BCI") is the manager of Bain Capital XIV General Partner, LLC ("BCPE Fund XIV GP"), which is the general partner of Bain Capital Fund XIV, L.P. ("BCPE Fund XIV"), which is the managing member of BCPE Perseus Investor GP, LLC ("BCPE Perseus GP"), which is the general partner of BCPE Perseus. As a result, each of BCI, BCPE Fund XIV GP, BCPE Fund XIV and BCPE Perseus GP may be deemed to share voting and dispositive power with respect to the securities held by BCPE Perseus. BCI, BCPE Fund XIV GP, BCPE Fund XIV and BCPE Perseus GP each disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

Key Figures

Series B Preferred shares: 17,857,143 shares Underlying common shares: 17,857,143 shares Conversion ratio: 1:1 +1 more

4 metrics

Series B Preferred shares 17,857,143 shares Indirect holdings reported on Form 3

Underlying common shares 17,857,143 shares 1:1 conversion from Series B Preferred Stock

Conversion ratio 1:1 Series B Preferred Stock into common stock

Conversion price 0.0000 per share Stated exercise/conversion price for Series B Preferred

Key Terms

Series B Preferred Stock, initial public offering, general partner, disclaims beneficial ownership

4 terms

Series B Preferred Stock financial

"Each share of the Issuer's Series B Preferred Stock is convertible..."

Series B preferred stock is a type of ownership share issued by a company that offers certain advantages over common stock, such as priority in receiving dividends or assets if the company is sold or liquidated. It is typically issued after an initial round of funding, making it a way for investors to support a company's growth while gaining some protections and benefits. This stock matters to investors because it often provides a more secure investment position with potential for future growth.

initial public offering financial

"and will automatically convert upon the closing of the Issuer's initial public offering."

An initial public offering (IPO) is when a private company first sells its shares to the public and becomes a stock-listed company. It matters because it allows the company to raise money from a wide range of investors, helping it grow, while giving early shareholders a way to sell some of their ownership.

general partner financial

"which is the general partner of Bain Capital Fund XIV, L.P...."

A general partner is the person or firm that runs an investment partnership and legally represents it — they make the day-to-day decisions, choose which assets to buy or sell, and are responsible for the partnership’s obligations. Investors care because the general partner’s judgment, risk-taking and fee and profit-sharing arrangements determine both the potential returns and the level of exposure to losses; think of the GP as the ship’s captain whose skill and honesty shape the voyage’s outcome.

disclaims beneficial ownership financial

"BCI, BCPE Fund XIV GP, BCPE Fund XIV and BCPE Perseus GP each disclaims beneficial ownership..."

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider position does Bain Capital report in Kailera Therapeutics (KLRA)?

Bain Capital–affiliated entities report indirect ten percent ownership in Kailera Therapeutics through 17,857,143 shares of Series B Preferred Stock. These shares are held directly by BCPE Perseus Investor, LP, with several Bain Capital funds and general partners positioned upstream in the ownership structure.

How many Kailera Therapeutics preferred shares are reported on this Form 3?

The Form 3 reports 17,857,143 shares of Kailera Therapeutics’ Series B Preferred Stock. Each preferred share is convertible into one share of common stock, so the position corresponds to 17,857,143 underlying common shares if fully converted on a 1:1 basis.

How is the Series B Preferred Stock of Kailera Therapeutics (KLRA) convertible?

Each share of Kailera’s Series B Preferred Stock is convertible into one share of common stock on a 1:1 basis. The preferred shares will automatically convert into common stock upon the closing of Kailera’s initial public offering and otherwise are convertible at the holder’s option.

Which Bain Capital entity directly holds Kailera’s Series B Preferred Stock?

BCPE Perseus Investor, LP directly holds the reported shares of Kailera’s Series B Preferred Stock. Other Bain Capital entities, including Bain Capital Fund XIV and related general partners, sit upstream and may be deemed to share voting and dispositive power over the securities held by BCPE Perseus.

Do Bain Capital entities fully acknowledge beneficial ownership of the Kailera shares?

The Bain Capital entities may be deemed to share voting and dispositive power over the BCPE Perseus holdings but each disclaims beneficial ownership. They recognize only their pecuniary interest in the securities, a common disclosure approach for complex private equity ownership structures.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Accepted by SEC EDGAR 04/16/2026 - 08:24 PM EDT Learn about SEC filing dates

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

BAIN CAPITAL INVESTORS LLC

(Last) (First) (Middle)

200 CLARENDON STREET

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

2. Date of Event Requiring Statement (Month/Day/Year)
04/16/2026

3. Issuer Name and Ticker or Trading Symbol
Kailera Therapeutics, Inc. [ KLRA ]

3a. Foreign Trading Symbol

5. If Amendment, Date of Original Filed (Month/Day/Year)

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Series B Preferred Stock	(1)	(1)	Common Stock	17,857,143	$0	I	See footnotes(2)(3)

1. Name and Address of Reporting Person^*

BAIN CAPITAL INVESTORS LLC

(Last) (First) (Middle)

200 CLARENDON STREET

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Bain Capital XIV General Partner, LLC

(Last) (First) (Middle)

200 CLARENDON STREET

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Bain Capital Fund XIV, L.P.

(Last) (First) (Middle)

200 CLARENDON STREET

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

BCPE Perseus Investor GP, LLC

(Last) (First) (Middle)

200 CLARENDON STREET

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

BCPE Perseus Investor, LP

(Last) (First) (Middle)

200 CLARENDON STREET

(Street)

BOSTON MASSACHUSETTS 02116

(City) (State) (Zip)

UNITED STATES

(Country)

Relationship of Reporting Person(s) to Issuer

	Director	X	10% Owner
	Officer (give title below)		Other (specify below)

Explanation of Responses:

1. Each share of the Issuer's Series B Preferred Stock is convertible, at the option of the holder, into shares of the Issuer's Common Stock on a 1:1 basis and will automatically convert upon the closing of the Issuer's initial public offering. These securities have no expiration date.

2. Represents shares of the Issuer's Series B Preferred Stock held directly by BCPE Perseus Investor, LP ("BCPE Perseus").

3. Bain Investors, LLC ("BCI") is the manager of Bain Capital XIV General Partner, LLC ("BCPE Fund XIV GP"), which is the general partner of Bain Capital Fund XIV, L.P. ("BCPE Fund XIV"), which is the managing member of BCPE Perseus Investor GP, LLC ("BCPE Perseus GP"), which is the general partner of BCPE Perseus. As a result, each of BCI, BCPE Fund XIV GP, BCPE Fund XIV and BCPE Perseus GP may be deemed to share voting and dispositive power with respect to the securities held by BCPE Perseus. BCI, BCPE Fund XIV GP, BCPE Fund XIV and BCPE Perseus GP each disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.

	See signatures included in Exhibit 99.1	04/16/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
* Form 3: SEC 1473 (03-26)