Westlake BioPartners Fund II, L.P. - 04 May 2023 Form 3 Insider Report for ACELYRIN, Inc. (SLRN)

Role: 10%+ Owner
Signature: /s/ Jennifer L. Kercher, Attorney-in-fact
Issuer symbol: SLRN
Transactions as of: 04 May 2023
Net transactions value: $0
Form type: 3
Filing time: 04 May 2023, 19:10:19 UTC
Next filing: 11 May 2023
SEC: View on sec.gov

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type	Sym	Class	Transaction	Value $	Shares	Change %	* Price $	Shares After	Date	Underlying Class	Amount	Exercise Price	Ownership	Footnotes
holding	SLRN	Series A Redeemable Convertible Preferred Stock							04 May 2023	Class A Common Stock	4,056,795		Direct	F1, F2, F3, F4
holding	SLRN	Series B Redeemable Convertible Preferred Stock							04 May 2023	Class A Common Stock	2,445,786		Direct	F1, F2, F3, F4
holding	SLRN	Series C Redeemable Convertible Preferred Stock							04 May 2023	Class A Common Stock	2,038,148		Direct	F1, F2, F3, F4

* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id	Content
F1	Each share of preferred stock is convertible into one share of Class A Common Stock or, subject to and in accordance with certain provisions set forth in the Issuer's certificate of incorporation, Class B Common Stock, and has no expiration date. Immediately prior to the completion of the Issuer's initial public offering of Common Stock (the "IPO"), all shares of preferred stock will automatically convert into shares of Common Stock.
F2	Each share of Class A Common Stock shall be reclassified into one share of Common Stock immediately prior to the completion of the IPO.
F3	Shares held directly by Westlake BioPartners Fund II, L.P., or Westlake Fund II. Westlake BioPartners GP II, LLC, or Westlake GP II, is the general partner of Westlake Fund II. Westlake GP II may be deemed to have sole voting and dispositive power with regard to the shares held directly by Westlake Fund II. Beth C. Seidenberg and Sean E. Harper are the Managing Directors of Westlake GP II and share voting and dispositive power over the shares held by Westlake Fund II, each of whom disclaims beneficial ownership of the shares held by Westlake Fund II except to the extent of such person's pecuniary interest therein, if any.
F4	This report on Form 3 is jointly filed by Westlake Fund II, Westlake GP II and Sean E. Harper. Each of the Reporting Persons disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of such person's or entity's pecuniary interest therein, if any. Westlake Fund II has designated a representative, Beth C. Seidenberg, a Managing Director of Westlake GP II, to serve on the Issuer's board of directors. This report shall not be deemed an admission that any such entity or person is a beneficial owner of such securities for the purposes of Section 16 of the Exchange Act, or for any other purpose.

Remarks:

Exhibit 24 - Power of Attorney