QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 PUMA BIOTECHNOLOGY, INC. Securities registered pursuant to Section12(b) of the Exchange Act: Indicate by check mark whether the registrant (1)has filed all reports required to be filed by Section13 or 15(d) of the Securities Exchange Act of 1934during 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 filing Indicate by check mark whether the registrant has submitted electronically every Interactive Data File required to be submitted pursuant to Rule 405 ofRegulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit such Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, a non-accelerated filer, a smaller reporting company or anemerging growth company.See the definitions of “large accelerated filer,” “accelerated filer,” “smaller reporting company” and “emerging growth company” If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period for complying with any new orrevised 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☒. Indicate the number of shares outstanding of each of the issuer’s classes of common stock, as of the latest practicable date.49,638,093shares of CommonStock, par value $0.0001 per share, were outstanding as ofMay 5, 2025. PUMA BIOTECHNOLOGY, INC. PART I–FINANCIAL INFORMATION: Item1.Financial Statements (Unaudited):Condensed Consolidated Balance Sheets as of March 31, 2025 and December 31, 2024Condensed Consolidated Statements of Operations for the Three Months Ended March 31, 2025 and 2024 PART II–OTHER INFORMATION: Item1.Legal ProceedingsItem 1A.Risk FactorsItem2.Unregistered Sales of Equity Securities and Use of ProceedsItem3.Defaults Upon Senior SecuritiesItem4.Mine Safety DisclosuresItem5.Other InformationItem6.ExhibitsSignatures CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS This Quarterly Report on Form 10-Q, (this “Quarterly Report”), contains forward-looking statements within the meaning ofSection21E of the Securities Exchange Act of 1934, as amended(the “Exchange Act”). Any statements about our expectations, beliefs, plans, •the commercialization of NERLYNX®(neratinib) tablets (“NERLYNX”);•the development of our drug candidates, including when we expect to undertake, initiate and complete clinical trials of our drugcandidates;•the anticipated timing of regulatory filings; •the regulatory approval of our drug candidates; •our use of clinical research organizations (“CRO”) and other contractors; •our ability to find collaborative partners for research, development and commercialization of potential products; •efforts of our sub-licensees to obtain regulatory approval and commercialize NERLYNX in areas outside the United States; •our ability to market any of our products; •our expectations regarding our costs and expenses; •our anticipated capital requirements and estimates regarding our needs for additional financing; •our ability to compete against other companies and research institutions; •our ability to secure adequate protection for our intellectual property; •our intention and ability to vigorously defend against any litigation to which we are or may become party; •our ability to in-license additional drugs; •our ability to attract and retain key personnel; and •our ability to obtain adequate financing on favorable terms or at all. These statements are often, but not always, made through the use of words or phrases such as “anticipate,” “estimate,” “plan,”“project,” “continuing,” “ongoing,” “expect,” “believe,” “intend” and similar words or phrases. Accordingly, these statements involveestimates, assumptions and uncertainties that could cause actual results to differ materially from those expressed in them. Discussionscontaining these forward-looking statements may be found throughout this Quarterly Report, including, in Part I, the section entitled “Item 2.Management’s Discussion and Analysis of Financial Condition and Results of Operations.” These forward-looking statements involve risksand uncertainties, including the risks discussed in Part I, Item 1A. “Risk Factors” of our Annual Report on Form 10-K for the year PUMA BIOTECHNOLOGY, INC. AND SUBSIDIARYCONDENSED CONSOLIDATED BALANCE SHEETS(in thousands, except share and per share data) PUMA BIOTECHNOLOGY, INC. AND SUBSIDIARYCONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS PUMA BIOTECHNOLOGY, INC. AND SUBSIDIARYNOTES TO THE UNAUDITED CONDENSED CONSOLIDATED FINANCIAL STATEMENTS Note1—Business and Basis of Presentation: Business and Liquidity: Puma Biotechnolog