Medicus Pharma Ltd美股招股说明书(2025-12-08版)

PROSPECTUS SUPPLEMENT NO. 3(to prospectus dated effective November 14, 2025) Medicus Pharma Ltd. Up to 7,500,000 Common Shares This prospectus supplement amends and supplements the prospectus dated effective November 14, 2025, as supplemented or amendedfrom time to time (the "Prospectus"), which forms a part of our Registration Statement on Form S-1 (Registration Statement No. 333-290585). This prospectus supplement is being filed to update and supplement the information included or incorporated by reference inthe Prospectus with the information contained in our Current Report on Form 8-K, filed with the Securities and Exchange Commissionon December 8, 2025 (the "Form 8-K"). Accordingly, we have attached the Form 8-K to this prospectus supplement. This prospectus supplement updates and supplements the information in the Prospectus and is not complete without, and may not bedelivered or utilized except in combination with, the Prospectus, including any amendments or supplements thereto. This prospectussupplement should be read in conjunction with the Prospectus and if there is any inconsistency between the information in theProspectus and this prospectus supplement, you should rely on the information in this prospectus supplement. Our common shares are listed on The Nasdaq Capital Market ("Nasdaq") under the symbol "MDCX". OnDecember 5, 2025, the lastreported sales price of the common shares was $2.05. We are an "emerging growth company" under applicable Securities and Exchange Commission rules and are eligible forreduced public company disclosure requirements. Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties describedunder the heading "Risk Factors" beginning on page 10 of the Prospectus, and under similar headings in any amendment orsupplements to the Prospectus. None of the Securities and Exchange Commission, any state securities commission or the securities commission of anyCanadian province or territory has approved or disapproved of the securities offered by this prospectus supplement or theProspectus or determined if the Prospectus or this prospectus supplement is truthful or complete. Any representation to thecontrary is a criminal offense. The date of this prospectus supplement is December 8, 2025. UNITED STATESSECURITIES AND EXCHANGE COMMISSIONWashington, D.C. 20549 ___________________________ FORM 8-K CURRENT REPORTPursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 Date of Report (Date of earliest event reported):December 5, 2025 MEDICUS PHARMA LTD. (Exact name of registrant as specified in its charter) Ontario(State or other jurisdictionof incorporation) 300 Conshohocken State Road, Suite 200Conshohocken, Pennsylvania, United States 19428(Address of principal executive offices) (ZIP Code) Registrant’s telephone number, including area code:(610) 540-7515 Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrantunder any of the following provisions: ☐Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) ☐Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) ☐Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) ☐Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) Securities registered pursuant to Section 12(b) of the Act: Indicate by check mark whether the registrant is an emerging growth company as defined in Rule 405 of the Securities Act of 1933 (§230.405 of this chapter) or Rule 12b-2 of the Securities Exchange Act of 1934 (§ 240.12b -2 of this chapter). Emerging growth company☑ If an emerging growth company, indicate by check mark if the registrant has elected not to use the extended transition period forcomplying with any new or revised financial accounting standards provided pursuant to Section 13(a) of the Exchange Act.☐ Item 1.01. Entry into a Material Definitive Agreement. Warrant Inducement Agreement On December 5, 2025, Medicus Pharma Ltd. (the "Company") entered into an inducement offer (the "Agreement") with acertain accredited and institutional holder (the "Holder") to exercise existing warrants to purchase up to 2,680,000 of the Company'scommon shares ("Common Shares") issued on July 14, 2025 at an amended exercise price of $1.92 per Common Share (the "ExistingWarrants"). Pursuant to the Agreement, the Holder, upon exercise, will receive new unregistered warrants (the "New Warrants") topurchase up to 4,020,000 Common Shares upon the exercise of the New Warrants (the "New Warrant Shares"), pursuant to Section4(a)(2) of the Securities Act of 1933, as amended ("Securities Act"). The New Warrants, which will be issued in two series, each containing 50% of the New Warrants, will have an exercise priceof $2.00 per Common Share, will be