A first patient, a quiet promise: manufacturing vididencel for Mendus’s CML immunotherapy trial

A look at how NorthX Biologics’ GMP manufacturing of Mendus’s vididencel supports the VITAL-CML trial and the patients’ unmet needs fueling the trials.

Author: Eva-Karin Gidlund, PhD, MBA, Chief Growth Officer & Deputy CEO, NorthX Biologics  |  September 2026

The human story behind every clinical milestone

For a person living with chronic myeloid leukemia (CML) or acute myeloid leukemia (AML), the enrolment of a first patient in a clinical trial is rarely a dry administrative line. It is a personal decision, taken at a particular point in a long journey shaped by side effects, follow-up tests, and the daily uncertainty that comes with a cancer diagnosis. When Mendus AB launched the Phase 1b VITAL-CML trial – and as the AMLM22-CADENCE Phase 2b study continues in acute myeloid leukemia – the headlines spoke about science. The reality, for those volunteers, is more human. Behind each clinical milestone there is a person who chose to step into the next chapter of their treatment story.

Survival is not the whole story: the unmet needs of those living with CML and AML

Patient stories shared by Mendus are reminders that survival statistics tell only part of the picture. Tyrosine kinase inhibitors (TKIs) have transformed CML from a once-fatal diagnosis into a chronic illness many patients manage for decades, with long-term survival now approaching that of the general population. Yet many patients continue to live with fatigue, cramps, eye swelling, and other side effects that affect work, family, and mental health. Only a portion of patients achieve the deep and sustained molecular response required to attempt treatment-free remission (TFR), and approximately 50% experience a molecular relapse after discontinuing TKI treatment. As a result, many CML patients remain dependent on lifelong daily treatment. In AML, the picture is considerably more challenging: many patients relapse after achieving a first complete remission, and long-term outcomes remain poor once the disease returns. For many patients, remission brings hope, but not certainty.

It is these unmet needs, from durable remission and long-term disease control in AML to quality of life and treatment-free remission in CML, that Mendus is working to address.

What vididencel is, and what it is not

Vididencel is Mendus’s lead investigational immunotherapy. It is an off-the-shelf, allogeneic active immunotherapy comprising irradiated leukemic-derived dendritic cells delivered by intradermal injection. The product expresses tumour-associated antigens and is designed to stimulate the patient’s own immune system to recognise and target residual cancer cells following first-line treatment.

Unlike autologous cell therapies, vididencel does not require patient-derived material or genetic engineering. It is produced from a proprietary cell line in a scalable manufacturing process, which means a single qualified batch can serve many patients. Across multiple clinical studies, vididencel has shown a favourable safety profile, with local injection-site reactions described as the principal adverse event. No serious product-related side effects have been reported. The product carries an EMA ATMP Manufacturing Certificate as well as Orphan Drug and Fast Track designations.

These are still early-phase data, in small populations, and they need to be read carefully. Vididencel is investigational. The studies now underway will establish whether the early signals translate into reproducible benefits for the patients who matter most: those who do not respond well to current therapies, and those who relapse.

VITAL-CML and AMLM22-CADENCE: two trials, two patient questions

VITAL-CML | Phase 1b trial | Norway

VITAL-CML is a Phase 1b trial being conducted in Norway under the leadership of Prof. Dr Bjørn Tore Gjertsen (University of Bergen and Haukeland University Hospital, Norway). It evaluates vididencel in chronic-phase CML patients with a sub-optimal response to currently approved TKIs. The study will recruit up to 24 patients. Topline safety and early molecular response data from the first eight patients were reported on September 11. This readout will also enable the initiation of VITAL-TFR2, a Phase 2a study designed to assess whether vididencel can increase the likelihood of durable TFR in CML patients who have previously failed a TFR attempt.

The key question is whether immunotherapy can help CML patients with a suboptimal response to TKI treatment achieve deeper and more durable responses, and whether it can ultimately help more patients stop treatment safely.

AMLM22-CADENCE | Phase 2b trial | Australia

AMLM22-CADENCE is a randomised Phase 2b trial conducted in Australia by the Australasian Leukaemia & Lymphoma Group (ALLG). It combines oral azacitidine with vididencel as post-remission / maintenance therapy for adults with cytogenetically intermediate- and high-risk acute myeloid leukemia in first complete remission. Mendus recently announced the initiation of the DIVA trial, further expanding the clinical evaluation of vididencel in AML.

The key question in AML is different: when remission is fragile, and the risk of relapse remains high, can immunotherapy help support more durable remissions?

Neither trial promises an answer. They are designed to determine whether immunotherapy can make a meaningful difference for patients.

GMP manufacturing: NorthX Biologic’s  role in the vididencel supply chain

NorthX Biologics is the contract development and manufacturing organisation (CDMO) supplying the GMP vididencel material used in these clinical studies. Our role is to support, not lead the science. Mendus develops the therapy, designs and runs the trials, and engages directly with the patient community. Our task is to make sure that every vial used in a clinical setting is manufactured to the standard the regulators, the investigators, and ultimately the patients require.

That work began with a strategic alliance announced in June 2023, in which Mendus and NorthX Biologics agreed to co-establish scalable, GMP-compliant cell therapy manufacturing for vididencel at NorthX’s facility in Matfors, Sweden. Over the following 18 months, the joint team adapted the Matfors site for allogeneic cell therapy production and completed the tech transfer of the vididencel process from earlier manufacturing partners. In December 2025, NorthX Biologics achieved GMP certification for vididencel manufacturing – the regulatory acknowledgement that the process and the facility meet the standards required to supply clinical programmes, including VITAL-CML and AMLM22-CADENCE.

We mention this not to claim a starring role. Manufacturing is one part of a larger system that also includes Mendus’s clinical and regulatory teams, the investigators in Norway and Australia, the hospital pharmacies and infusion centres, and the patients themselves. But it is a part for which we feel a particular responsibility. A trial is only as reproducible as its product. Each batch of vididencel must be the same product that earlier patients received, and each delivery must arrive in time for an appointment that may have been months in the planning.

Why this partnership matters to NorthX Biologics and Mendus

For us, supporting Mendus is more than a contract. It is an opportunity to put more than thirty years of GMP biologics experience, spanning plasmid DNA, proteins, vaccines and now cell therapies, behind a programme that addresses an unmet need patients themselves have articulated. The CML community has been clear, through advocacy networks and through patient stories, about what they would like research to deliver: more options for patients who do not respond to first-line therapies; safer paths to treatment-free remission; better tools for those still on lifelong medication. The AML community, facing higher relapse rates and shorter remissions, is seeking new approaches that can help remissions last longer and improve survival.

We cannot promise that vididencel will answer those questions. The trials will help determine the answer. What we can do, and what we feel privileged to do, is make sure that every patient who agrees to participate receives a product that has been manufactured with the care their decision deserves.

A first patient enrolment is, on paper, a small number. In practice, it is a very specific person, on a very specific day, agreeing to help a community of people they have likely never met. NorthX Biologics is honoured to play a quiet part in that story. We will continue to do so, batch by batch, for as long as Mendus, the investigators, and most importantly the patients, believe this work is worth doing.

About Mendus

Mendus AB (publ; IMMU.ST) is a clinical-stage biopharmaceutical company dedicated to transforming immunotherapy for myeloid blood cancers. Based in Sweden and the Netherlands, Mendus is publicly traded on the Nasdaq Stockholm under the ticker IMMU.ST. Learn more at mendus.com.

References

• Mendus press release: “Mendus announces initiation of the DIVA trial” (September 2026);
• Mendus press release: “Mendus reports positive read-out for first stage VITAL-CML trial”(September 2026);
• Mendus press release: “Mendus announces first patient enrolled in the VITAL-CML trial” (April 2026);
• Mendus press release: “First patient enrolled in the AMLM22-CADENCE trial with Mendus’ product vididencel”;
• NorthX Biologics, “NorthX Biologics achieves milestone GMP certification to manufacture vididencel” (December 2025);

• NorthX Biologics & Mendus, “Strategic cell therapy manufacturing alliance” (June 2023).

Note: This article describes investigational therapies that have not been approved by any regulatory authority. Forward-looking statements are subject to risks and uncertainties.