Onconova Cross announced in a regulatory filing on the 1st that it has signed a joint research and development contract with Aptis Co., Ltd. concerning antibody-drug conjugate (ADC) or bispecific antibody-drug conjugate (BsADC) candidates.

■ Contract Scale…755.82% of Revenue The total contract fee and research and development (R&D) stage-by-stage milestone payments amount to 2.8 billion won, excluding value-added tax. This is equivalent to 755.82% of Onconova Cross's revenue of 370,465,589 won based on its 2025 financial statements. Revenue-sharing amounts from technology transfer (licensing out) to third parties are not included in the total contract fee and milestone amount.

■ Division of Roles Through this program, Onconova Cross will discover and derive novel targets and antibody candidates and provide them to Aptis. Specifically, it will be responsible for the discovery and validation of novel targets and the derivation and production of antibody candidates. Aptis will use these to finalize ADC or BsADC candidates through antibody assembly and payload conjugation, and subsequently lead further development, including non-clinical and clinical studies, as well as commercialization.

■ Intellectual Property and Contract Period The intellectual property rights related to the antibodies derived by Onconova Cross in this program will be transferred to Aptis upon payment of the Phase 1 clinical milestone. The contract period runs from September 1 until all rights and obligations of both companies regarding the program are fulfilled or extinguished. The end date has not been separately specified.

■ Technology Transfer Revenue Sharing If Aptis transfers the program-related rights to a non-affiliated third party, Onconova Cross will receive a share of the technology transfer proceeds.

■ Risk Factors Details of the contract fee, stage-by-stage milestones, and technology transfer revenue sharing were not disclosed due to confidentiality obligations under the contract. However, the total contract fee and milestone amount includes conditional payments to be received upon achieving conditions at each R&D stage. Whether payments are received and their amounts may vary depending on the progress of R&D, the achievement of each payment condition, and whether a third-party technology transfer occurs. Depending on R&D outcomes, subsequent milestones may not be paid or the contract may be terminated.