Mendus AB (publ): Mendus AB Interim Report January – March 2026

Start of clinical program in chronic myeloid leukemia As part of its updated clinical strategy communicated end of 2025, Mendus is expanding clinical development of the lead product vididencel to include chronic myeloid leukemia (CML). Enrollment of the first patient in the VITAL-CML trial marked the start of clinical development in CML. In parallel, Mendus started a collaboration with the Olivia Newton-John Cancer Research Institute (ONJCRI), a leading Australian cancer research institute, to support the DIVA trial in acute myeloid leukemia (AML). The trial will commence in the summer and assess vididencel in combination with less intensive induction therapy, further consolidating the position of vididencel as a post-remission immunotherapy. Erik Manting, Ph.D. Chief Executive Officer Significant events of Q1 2026

Net sales for the period amounted to KSEK - (-)

Result for the period amounted to KSEK –21,022 (-30,482)

Earnings and diluted earnings per share totaled to SEK –0.34 (-0.61)

Mendus entered into an agreement with the Olivia Newton-John Cancer Research Institute (ONJCRI), a leading Australian cancer research institute, to support the DIVA trial with the company’s lead product vididencel in AML (acute myeloid leukemia).

Mendus requested drawdown of SEK 30 million under the loan facility totaling SEK 50 million entered into with Fenja Capital II A/S in November 2025. Furthermore, the company's board of directors resolved, pursuant to the authorization from an extraordinary general meeting in December 2025, and in accordance with the terms and conditions of the loan facility, on a directed issue of 1,935,605 warrants of series 2025/2030 to Fenja. Significant events after end of reporting period

Mendus announced an Mendus announced start of clinical program in CML (chronic myeloid leukemia). The company has completed preparations and received all regulatory approvals for the VITAL-CML trial, marking the start of clinical development with the company’s lead product vididencel CML.

Mendus announced that the first patient has been enrolled in the VITAL-CML trial, which evaluates vididencel in chronic phase CML patients with a sub-optimal response to currently approved tyrosine kinase inhibitors (TKIs). Financial summary +---------------------------------------------+---------+---------+----------+ | | 2026 | 2025 | 2025 | | | | | | +---------------------------------------------+---------+---------+----------+ | Amounts in KSEK | Jan-Mar | Jan-Mar | Jan-Dec | +---------------------------------------------+---------+---------+----------+ | Revenue | – | – | – | +---------------------------------------------+---------+---------+----------+ | Operating profit/loss | -20,095 | -30,222 | -113,491 | +---------------------------------------------+---------+---------+----------+ | Net profit/loss | -21,022 | -30,482 | -113,258 | +---------------------------------------------+---------+---------+----------+ | Earnings/loss per share, before and after | -0.34 | -0.61 | -2.17 | | dilution (SEK) | | | | +---------------------------------------------+---------+---------+----------+ | Cash | 74,128 | 84,730 | 64,656 | +---------------------------------------------+---------+---------+----------+ | Shareholders equity | 565,137 | 614,539 | 585,065 | +---------------------------------------------+---------+---------+----------+ | Number of employees | 19 | 28 | 19 | +---------------------------------------------+---------+---------+----------+ The full report is attached as PDF and is available on the company’s website: https://mendus.com/investors/financial-reports/ Webcast investor call, May 8 at 14.00 CEST The company will host a live presentation and business update today at 14:00 CEST. The presentation will be held in English and includes a Q&A session. If you wish to participate via webcast please use the link below. Via the audiocast you are able to ask written questions. https://mendus.events.inderes.com/q1-report-2026/register If you wish to participate via teleconference please register on the link below. After registration you will be provided phone numbers and a conference ID to access the conference. You can ask questions verbally via the teleconference. https://events.inderes.com/mendus/q1-report-2026/dial-in For more information, please contact: Erik Manting Chief Executive Officer E-mail: ir@mendus.com About Mendus AB (publ) Mendus is dedicated to changing the course of cancer treatment by addressing tumor recurrence and improving long-term survival for cancer patients, while preserving health and quality of life. We leverage our understanding of dendritic cell biology to develop an advanced clinical pipeline of immunotherapies that combine clinical efficacy with a benign safety profile. Based in Sweden and The Netherlands, Mendus is publicly traded on the Nasdaq Stockholm under the ticker IMMU.ST. https://www.mendus.com/ Attachments Mendus 26Q1 ENG (https://storage.mfn.se/9c0344ea-b69f-48ef-bb79-3357b48de1f3/mendus-26q1-eng.pdf) Mendus AB Interim Report January – March 2026 (https://storage.mfn.se/50dd06fd-489b-4e30-80c9-efa32d53f811/mendus-ab-interim-report-january-march-2026.pdf)