Oncomatryx, an EIC Accelerator Winner, Targets the Tumour Stroma

Oncomatryx aims its cancer drugs not at the cancer cell but at the tissue around it. The company from the Basque Country builds antibody-drug conjugates, antibodies that carry a toxic payload, against fibroblast activation protein (FAP), a marker on the cancer-associated fibroblasts in the stroma of solid tumours. The thesis, in the words of chief executive Laureano Simón, is that the novelty lies "in targeting the surroundings of the tumour rather than the tumour itself", as he told Cadena SER in an interview reported by The Spanish Eye.

The EIC Accelerator selected its project, ONCO-DART, at the March 2025 cut-off for blended finance. CORDIS records a grant agreement signed on 31 October 2025 with an EU contribution of €2,499,375.90, running from 1 November 2025 to 31 October 2027, to take the lead drug OMTX705 through Phase Ib and II trials. The company announced on 15 July 2025 that the award also includes a €10 million equity investment in its next financing round, a figure CORDIS repeats as what the company applied for.

An antibody aimed at the tumour's shield

OMTX705 joins a humanised anti-FAP antibody, OMTX005, to TAM470, a synthetic microtubule inhibitor from the tubulysin family. The founding data are in a 2020 paper in Clinical Cancer Research, a joint study that the University of Stuttgart's Institute of Cell Biology and Immunology also announced. In patient-derived tumour models the authors report 100% tumour growth inhibition alone and with chemotherapy, and in a mouse model with a humanised immune system that resisted anti-PD-1 therapy, more killer T cells inside the tumour and complete regressions. These are animal results.

The difference the company claims is the target. FAP sits on the fibroblasts around the tumour rather than on the cancer cell, and the company's case is that destroying them both kills nearby cancer cells and opens so-called immune-cold tumours to checkpoint inhibitors. Each registered OMTX705 trial includes arms that pair it with the anti-PD-1 antibodies pembrolizumab or tislelizumab.

A second programme follows the same logic. In October 2026 the company announced a paper in Science Advances, led by the Dr. Margarete Fischer-Bosch Institute in Stuttgart, on OMTX305, a bispecific antibody that directs T cells against the same fibroblasts: in tumour slices from 15 lung and ovarian cancer patients, the area occupied by fibroblasts fell from 38% to 24% in three days. Ecosistema Startup reported the same study, and the company's own scientific chief cautions about what it shows.

Around 100 patients, and no response rate in public

The first trial, NCT05547321, began on 20 October 2022 and tests OMTX705 alone and with an anti-PD-1 antibody in advanced solid tumours, at sites in Spain and at Beth Israel Deaconess Medical Center in Boston. The registry lists it as recruiting, with 150 planned patients and an estimated completion in December 2027. Its later arms include FAP-positive sarcoma and two pancreatic cancer doses with tislelizumab.

The July 2025 release says data from 95 patients in dose escalation and three backfill cohorts were presented at ASCO 2025 and showed no dose-limiting toxicity. The Spanish Eye, citing the same presentation, reports a favourable safety profile and extended disease control, with nearly 100 patients treated. Neither source gives a response rate, median survival or the share of patients whose tumours shrank, and the abstract itself could not be found in web searches on 28 October 2026. Safety without dose-limiting toxicity is what a Phase I is designed to show; whether the drug works is what the trials funded by ONCO-DART are meant to establish.

Two combination trials are registered. NCT07377045 adds OMTX705 and tislelizumab to the standard gemcitabine and nab-paclitaxel in metastatic pancreatic cancer, started on 28 October 2025, plans 69 patients and runs to March 2029; the CRO TFS HealthScience supports it, per MedPath. A Phase Ib/2 study in colorectal cancer, EU trial 2025-520743-33, combines it with regorafenib and tislelizumab and is listed as recruiting by the Clínica Universidad de Navarra. Both ClinicalTrials.gov entries still name the sponsor as an S.L.

In Asia the drug is partnered. InxMed of Nanjing announced on 29 August 2023 that China's drug regulator had cleared a Phase I trial of OMTX705, and that it co-develops the drug and holds its commercial rights in Asia; the CORDIS summary describes the same licence as covering East Asia. The date and financial terms of the agreement are not public. CORDIS also records that the company anticipates a €700 million licensing deal for North America, Europe and Japan after Phase II, which is a target, not a contract.

Funded mostly by Spanish public money

Most of the company's recent money comes from public investors and foundations. In January 2025 it announced €25 million for Phase Ib-II trials, led by existing investors and including €10 million from the Spanish innovation agency CDTI through its Innvierte programme, as Pulse 2.0 also reported. In March 2026 Capital Riesgo reported a capital increase of about €58 million: €24.3 million from INNVIERTE, €15 million from Kutxa Fundazioa, which raised its stake from 1.7% to 7.4%, and €10.4 million from the Basque Government with Ekarpen, which kept its 17.96%. The company's English release, reported by Pulse 2.0 on 30 March 2026, gives the same round as $67 million and adds BBK and other private investors.

Whether the EIC's announced €10 million of equity has been paid in is not public. Neither account of the March 2026 round names the EIC Fund among the investors. A page for the company exists at the address of the EIC Fund portfolio, but it returned "Access denied" when checked on 28 October 2026, so no amount or date could be read from it.

What the register shows

The Bizkaia commercial register, through the official gazette BORME, records three structural changes since 2023. On 15 September 2023 the shareholders approved the merger by absorption of TUBE Pharmaceuticals GmbH. On 30 June 2025 the general meeting approved the conversion from a sociedad limitada into a sociedad anónima, on a balance sheet closed at 31 December 2024. The register recorded the change on 1 October 2025, together with a new board that includes the Basque venture capital manager Gestión de Capital Riesgo del País Vasco and Ekarpen Private Equity, and a board term extended to six years. Filed accounts, revenue and staff numbers could not be read from a free source; the investor database PitchBook estimates 36 employees, which is not a filed figure.

Why the EU funds it

The Commission's Beating Cancer Plan page counts 2.7 million diagnoses and 1.3 million deaths in the EU in 2024 and expects cases to rise by 24% by 2035, and it names Horizon Europe among the plan's funders. Some metastatic colorectal and pancreatic cancers respond poorly to immunotherapy, The Spanish Eye notes, and these are the tumours the OMTX705 combinations target. The Capital Riesgo report ties the 2026 round to a planned plant in Gipuzkoa for high-potency oncology drugs. The July 2025 release says the Spanish government designated Oncomatryx a strategic company, and the Basque industry minister, quoted by Pulse 2.0 in March 2026, called the specialised biotechnology sector strategic.

1. Phase Ib in pancreatic cancerRunningNCT07377045 started 28 October 2025, recruiting, 69 patients planned.
2. Phase Ib/2 in colorectal cancerRecruitingEU trial 2025-520743-33, listed by Clínica Universidad de Navarra.
3. Efficacy data from Phase Ib-IINot yet publicThe March 2026 release promised results at conferences during 2026; none found by 28 October 2026.
4. €10M EIC equity investmentNot confirmedAnnounced by the company; not named in the March 2026 round.
5. Licensing deal for the West and JapanTargetPlanned after Phase II, per CORDIS.

The reporting is based on publicly available sources, listed below.