Key facts
- This page summarizes Bain Capital Life Sciences Investors, LLC's Form 4 filing for Kailera Therapeutics, Inc. (KLRA).
- 5 reported transactions and 10 derivative rows are listed below.
- Accepted by SEC: 20 Apr 2026, 18:01.
Bain Capital Life Sciences Investors, LLC - 20 Apr 2026 Form 4 Insider Report for Kailera Therapeutics, Inc. (KLRA)
- Reporting relationship
- 10%+ Owner
- Issuer ticker
- KLRA
- Reported as of
- 20 Apr 2026
- Net transaction value
- $0
- SEC form
- 4
- Accepted by SEC
- 20 Apr 2026, 18:01:46 UTC
- Prior SEC filing
- 16 Apr 2026
- Next SEC filing
- 30 Apr 2026
- Source filing
- View source filing
- Reporting owner signature
- See signatures included in Exhibit 99.1
Source evidence
Original filing metadata and source links for verification.
5 source fields
Reporting owner
1 detail
Filing notes and source
Key filing fact
Bain Capital Life Sciences Investors, LLC filed Form 4 for Kailera Therapeutics, Inc. (KLRA) on 20 Apr 2026.
Change
- Previous filing in this sequence was filed on 16 Apr 2026.
- Current net transaction value: $0.
Research use
- This tells you what this filing adds before you inspect full transaction and derivative tables.
- You can trace every row back to the original SEC filing document.
Evidence
Filed on Form 4
View source filing
Ownership activity is grounded in SEC Form 4 disclosures.
Reporting Owners (5)
CIK 0001703031
Primary reporting owner
Bain Capital Life Sciences Investors, LLC
- Relationship
- 10%+ Owner
- Address
- 200 CLARENDON STREET, BOSTON
- Signature
- See signatures included in Exhibit 99.1
- Signature date
- 20 Apr 2026
CIK 0001996931
Bain Capital Life Sciences IV General Partner, LLC
- Relationship
- 10%+ Owner
- Address
- 200 CLARENDON STREET, BOSTON
- Signature
- See signatures included in Exhibit 99.1
- Signature date
- 20 Apr 2026
CIK 0001996979
Bain Capital Life Sciences Fund IV, L.P.
- Relationship
- 10%+ Owner
- Address
- 200 CLARENDON STREET, BOSTON
- Signature
- See signatures included in Exhibit 99.1
- Signature date
- 20 Apr 2026
CIK 0002015967
BCLS Fund IV Investments GP, LLC
- Relationship
- 10%+ Owner
- Address
- 200 CLARENDON STREET, BOSTON
- Signature
- See signatures included in Exhibit 99.1
- Signature date
- 20 Apr 2026
CIK 0002015454
BCLS Fund IV Investments, L.P.
- Relationship
- 10%+ Owner
- Address
- 200 CLARENDON STREET, BOSTON
- Signature
- See signatures included in Exhibit 99.1
- Signature date
- 20 Apr 2026
Reported non-derivative transactions
Shares, units, or other non-derivative securities reported in this filing.
KLRA
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +16,875,000
- Change %
- Price
- Shares after
- 16,875,000
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F1, F3, F4
KLRA
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +16,875,000
- Change %
- Price
- Shares after
- 16,875,000
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F1, F3, F4
KLRA
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +16,875,000
- Change %
- Price
- Shares after
- 16,875,000
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F1, F3, F4
KLRA
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +16,875,000
- Change %
- Price
- Shares after
- 16,875,000
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F1, F3, F4
KLRA
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +16,875,000
- Change %
- Price
- Shares after
- 16,875,000
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F1, F3, F4
KLRA
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +4,145,768
- Change %
- +25%
- Price
- Shares after
- 21,020,768
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F2, F3, F4
KLRA
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +4,145,768
- Change %
- +25%
- Price
- Shares after
- 21,020,768
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F2, F3, F4
KLRA
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +4,145,768
- Change %
- +25%
- Price
- Shares after
- 21,020,768
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F2, F3, F4
KLRA
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +4,145,768
- Change %
- +25%
- Price
- Shares after
- 21,020,768
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F2, F3, F4
KLRA
transaction
Common Stock
Conversion of derivative security
- Transaction value
- Shares
- +4,145,768
- Change %
- +25%
- Price
- Shares after
- 21,020,768
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F2, F3, F4
KLRA
transaction
Common Stock
Purchase
- Transaction value
- Shares
- +1,562,500
- Change %
- +7.4%
- Price
- $16.00*
- Shares after
- 22,583,268
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F3, F4
KLRA
transaction
Common Stock
Purchase
- Transaction value
- Shares
- +1,562,500
- Change %
- +7.4%
- Price
- $16.00*
- Shares after
- 22,583,268
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F3, F4
KLRA
transaction
Common Stock
Purchase
- Transaction value
- Shares
- +1,562,500
- Change %
- +7.4%
- Price
- $16.00*
- Shares after
- 22,583,268
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F3, F4
KLRA
transaction
Common Stock
Purchase
- Transaction value
- Shares
- +1,562,500
- Change %
- +7.4%
- Price
- $16.00*
- Shares after
- 22,583,268
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F3, F4
KLRA
transaction
Common Stock
Purchase
- Transaction value
- Shares
- +1,562,500
- Change %
- +7.4%
- Price
- $16.00*
- Shares after
- 22,583,268
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Footnotes
- F3, F4
Reported derivative securities
Options, warrants, convertible securities, or similar derivative positions disclosed in the filing.
KLRA
transaction
Derivative
Series A-1 Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -16,875,000
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Underlying class
- Common Stock
- Underlying amount
- 16,875,000
- Exercise price
- Footnotes
- F1, F3, F4
KLRA
transaction
Derivative
Series A-1 Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -16,875,000
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Underlying class
- Common Stock
- Underlying amount
- 16,875,000
- Exercise price
- Footnotes
- F1, F3, F4
KLRA
transaction
Derivative
Series A-1 Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -16,875,000
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Underlying class
- Common Stock
- Underlying amount
- 16,875,000
- Exercise price
- Footnotes
- F1, F3, F4
KLRA
transaction
Derivative
Series A-1 Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -16,875,000
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Underlying class
- Common Stock
- Underlying amount
- 16,875,000
- Exercise price
- Footnotes
- F1, F3, F4
KLRA
transaction
Derivative
Series A-1 Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -16,875,000
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Underlying class
- Common Stock
- Underlying amount
- 16,875,000
- Exercise price
- Footnotes
- F1, F3, F4
KLRA
transaction
Derivative
Series B Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -4,145,768
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Underlying class
- Common Stock
- Underlying amount
- 4,145,768
- Exercise price
- Footnotes
- F2, F3, F4
KLRA
transaction
Derivative
Series B Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -4,145,768
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Underlying class
- Common Stock
- Underlying amount
- 4,145,768
- Exercise price
- Footnotes
- F2, F3, F4
KLRA
transaction
Derivative
Series B Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -4,145,768
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Underlying class
- Common Stock
- Underlying amount
- 4,145,768
- Exercise price
- Footnotes
- F2, F3, F4
KLRA
transaction
Derivative
Series B Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -4,145,768
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Underlying class
- Common Stock
- Underlying amount
- 4,145,768
- Exercise price
- Footnotes
- F2, F3, F4
KLRA
transaction
Derivative
Series B Preferred Stock
Conversion of derivative security
- Transaction value
- Shares
- -4,145,768
- Change %
- -100%
- Price
- $0.000000*
- Shares after
- 0
- Date
- 20 Apr 2026
- Ownership
- See footnotes
- Underlying class
- Common Stock
- Underlying amount
- 4,145,768
- Exercise price
- Footnotes
- F2, F3, F4
* marks a reported price that did not pass the local price check.
Additional SEC filing notes
Filing notes and footnotes
Explanation of responses 4 footnotes
Footnote F1
Each share of the Issuer's Series A-1 Preferred Stock automatically converted into shares of the Issuer's Common Stock on a 1:1 basis upon the closing of the Issuer's initial public offering. These securities had no expiration date.
Footnote F2
Each share of the Issuer's Series B Preferred Stock automatically converted into shares of the Issuer's Common Stock on a 1:1 basis upon the closing of the Issuer's initial public offering. These securities had no expiration date.
Footnote F3
Represents securities held directly by BCLS Fund IV Investments, LP ("BCLS Fund IV Investments").
Footnote F4
Bain Capital Life Sciences Investors, LLC ("BCLSI") is the manager of Bain Capital Life Sciences IV General Partner, LLC ("BCLS Fund IV GP"), which is the general partner of Bain Capital Life Sciences Fund IV, L.P. ("BCLS Fund IV"), which is the managing member of BCLS Fund IV Investments GP, LLC ("BCLS Fund IV Investments GP"), which is the general partner of BCLS Fund IV Investments. As a result, each of BCLSI, BCLS Fund IV GP, BCLS Fund IV and BCLS Fund IV Investments GP may be deemed to share voting and dispositive power with respect to the securities held by BCLS Fund IV Investments. BCLSI, BCLS Fund IV GP, BCLS Fund IV and BCLS Fund IV Investments GP each disclaims beneficial ownership of such securities except to the extent of its pecuniary interest therein.