LB Pharmaceuticals Inc美股招股说明书(2026-05-12版)

This prospectus supplement is being filed to update, amend and supplement the information included in the Prospectus with theinformation contained in our Quarterly Report on Form 10-Q filed with the Securities and Exchange Commission on May 12, 2026,which is set forth below. This prospectus supplement is not complete without the Prospectus. This prospectus supplement should be read in conjunction withthe Prospectus, which is to be delivered with this prospectus supplement, and is qualified by reference thereto, except to the extentthat the information in this prospectus supplement updates or supersedes the information contained in the Prospectus. Please keepthis prospectus supplement with your Prospectus for future reference. Our common stock is listed on The Nasdaq Global Market under the symbol “LBRX.” On May 7, 2026, the last reported sale priceof our common stock was $31.98 per share. Investing in our securities involves a high degree of risk. You should review carefully the risks anduncertainties described in the section titled “Risk Factors” beginning on page 8 of the Prospectus, andunder similar headings in any amendments or supplements to the Prospectus. Neither the Securities and Exchange Commission nor any other state securities commission has approved or disapproved ofthese securities or passed upon the accuracy or adequacy of the Prospectus or this prospectus supplement. Anyrepresentation to the contrary is a criminal offense. The date of this prospectus supplement is May 12, 2026 UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWASHINGTON, DC 20549 FORM 10-Q (Mark One)☒QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF1934 For the quarterly period ended March 31, 2026 OR ☐TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF1934 For the transition period from ______ to _________Commission File Number: 001-42831 LB Pharmaceuticals Inc (Exact Name of Registrant as Specified in its Charter) Registrant’s telephone number, including area code: (212) 605-0300 Securities registered pursuant to Section 12(b) of the Act: Title of each classTradingSymbol(s)Name of each exchange on which registeredCommon Stock, $0.0001 par valueLBRXThe Nasdaq Stock Market LLC Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filingrequirements for the past 90 days.Yes☒No☐ Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit suchfiles).Yes☒No☐ Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, smaller reporting company,or an emerging growth company. See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company,” and “emerging growthcompany” in Rule 12b-2 of the Exchange Act. Large accelerated filer☐Non-accelerated filer☒Emerging growth company☒ Accelerated filer☐Smaller reporting company☒ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying withany new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Indicate by check mark whether the registrant is a shell company (as defined in Rule 12b-2 of the Exchange Act).Yes☐No☒ The number of shares of Registrant’s Common Stock outstanding as of May 7, 2026 was 28,676,652. Table of Contents Special Note Regarding Forward-Looking StatementsiiRisk Factors Summaryv PART I.FINANCIAL INFORMATION Item 1.Financial Statements (Unaudited)1Condensed Balance Sheets as of March 31, 2026 and December 31, 20251Condensed Statements of Operations for the Three Months Ended March 31, 2026 and 20252Condensed Statements of Comprehensive Loss for the Three Months Ended March 31, 2026 and 20253Condensed Statements of Redeemable Convertible Preferred Stock and Stockholders’ Equity (Deficit) forthe Three Months Ended March 31, 2026 and 20254Condensed Statements of Cash Flows for the Three Months Ended March 31, 2026 and 20255Notes to Condensed Financial Statements6Item 2.Management’s Discussion and Analysis of Financial Condition and Results of Operations19Item 3.Quantitative and Qualitative Disclosures About Market Risk28Item 4.Controls and Procedures28 PART II.OTHER INFORMATION Item 1.Legal Proceedings30Item 1A.Risk Factors30Item 2.Unregistered Sales of Equity Securities and Use of Proceeds85Item 3.Defaults Upon Senior Securities85Item 4.Mine Safety Disclosures85Item 5.Other Information85It