On July 3, 2025, we entered into a certain Sales Agreement, or sales agreement, with A.G.P./Alliance Global Partners (“A.G.P.”)relating to shares of our common stock offered by this prospectus supplement and the accompanying prospectus. In accordance with the terms of the sales agreement, we may offer and sell shares of our common stock having an aggregate offering price of up to$50,000,000 from time to time through A.G.P., acting as our sales agent or principal. We are an “emerging growth company” and “smaller reporting company” as defined under U.S. federal securities laws and are subject to reduced public company reporting requirements. Our shares of common stock are listed on The Nasdaq Stock Market (“Nasdaq”)under the symbol “KLTO”. The last sale price of our shares of common stock on July 25, 2025 was $1.23 per share.Sales of our common stock, if any, under this prospectus supplement may be made in sales deemed to be “at the market offerings” as related to such prevailing market prices and/or in any other method permitted by law. If we and A.G.P. agree on any method ofdistribution other than sales of shares of our common stock on or through Nasdaq or another existing trading market in the UnitedStates at market prices, we will file a further prospectus supplement providing all information about such offering as required by Rule424(b) under the Securities Act. A.G.P. is not required to sell any specific number or dollar amount of securities but will act as a sales A.G.P. and us. There is no arrangement for funds to be received in any escrow, trust or similar arrangement.The compensation to A.G.P. for sales of common stock sold pursuant to the sales agreement will be equal to 3.0% of the grossproceeds of any shares of common stock sold under the sales agreement, in addition to reimbursement of certain expenses. See “Planof Distribution.” In connection with the sale of the common stock on our behalf, A.G.P. will be deemed to be an “underwriter” withinthe meaning of the Securities Act and the compensation of A.G.P. will be deemed to be underwriting commissions or discounts. Wehave also agreed to provide indemnification and contribution to A.G.P. with respect to certain liabilities, including liabilities under theSecurities Act or the Securities Exchange Act of 1934, as amended (the “Exchange Act”). securities or passed upon the adequacy or accuracy of this prospectus supplement or the accompanying prospectus. Anyrepresentation to the contrary is a criminal offense.A.G.P. This prospectus supplement and the accompanying prospectus are part of a registration statement that we filed with the Securities andExchange Commission (the “SEC”) utilizing a “shelf” registration process. Each time we conduct an offering to sell securities underthe accompanying prospectus we will provide a prospectus supplement that will contain specific information about the terms of thatoffering, including the price, the amount of securities being offered and the plan of distribution. The shelf registration statement was prospectus. The accompanying prospectus provides general information about us and our securities, some of which, such as the sectionentitled “Plan of Distribution,” may not apply to this offering. This prospectus supplement and the accompanying prospectus are anoffer to sell only the securities offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. We are not in which the person making that offer or solicitation is not qualified to do so or to anyone to whom it is unlawful to make an offer orsolicitation.If information in this prospectus supplement is inconsistent with the accompanying prospectus or the information incorporated by writing prospectus we have authorized for use in connection with this offering include all material information relating to this offering.We have not authorized anyone to provide you with different or additional information and you must not rely on any unauthorizedinformation or representations. You should assume that the information appearing in this prospectus supplement, the accompanyingprospectus, the documents incorporated by reference in this prospectus supplement and the accompanying prospectus and any freewriting prospectus we have authorized for use in connection with this offering is accurate only as of the respective dates of thosedocuments. Our business, financial condition, results of operations and prospects may have changed since those dates. You shouldcarefully read this prospectus supplement, the accompanying prospectus and the information and documents incorporated herein byreference herein and therein, as well as any free writing prospectus we have authorized for use in connection with this offering, before No action is being taken in any jurisdiction outside the United States to permit a public offering of these securities or possession ordistribution of this prospectus supplement or the accompanying prospectus in that ju




