Indicate by check mark whether the registrant files or will file annual
reports under cover of Form 20-F or Form 40-F.
On October 1, 2026,
the Company issued a press release titled, “Agomab Reports Positive Topline Data from STENOVA Open-Label Extension Study of Ontunisertib
in Fibrostenosing Crohn’s Disease.” A copy of this press release is attached hereto as Exhibit 99.1 and is incorporated
herein by reference.
This Report of Foreign Private
Issuer on Form 6-K may contain forward-looking statements, within the meaning of the Private Securities Litigation Reform Act of
1995, as amended, which can generally be identified as such by the use of words such as “may,” “will,” “estimate,”
“future,” “forward,” “anticipate,” or other similar words. Any statement describing the Company’s
future plans, strategies, intentions, expectations, objectives, goals or prospects, and other statements that are not historical facts,
are also forward-looking statements, including, but not limited to, statements regarding: the potential of ontunisertib for the treatment
of Fibrostenosing Crohn’s disease, the expected initiation of the NOV-ERA Phase 2b study, our interactions with regulatory authorities
and the Company’s future expectations, plans and prospects. Such statements are based on the Company’s current expectations
and projections about future events and future trends affecting its business and are subject to certain risks and uncertainties that could
cause actual results to differ materially from those anticipated in the forward-looking statements, including risks and uncertainties:
associated with clinical and preclinical trials and product development, including the risk that preliminary or interim data may not reflect
final results, related to regulatory approvals, and related to the impact of global economic conditions. These and other risks and uncertainties
are described more fully in the Company’s Annual Report, filed on Form 20-F with the SEC, and in subsequent filings with the
SEC. The Company undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future
events, or otherwise, except as required under applicable law. Investors should not place undue reliance on these forward-looking statements,
which apply only as of the date of this Report of Foreign Private Issuer on Form 6-K.
Pursuant to the requirements
of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned, thereunto
duly authorized.
Exhibit 99.1
Agomab Reports
Positive Topline Data from STENOVA Open-Label Extension Study of Ontunisertib in Fibrostenosing Crohn’s Disease
-- Favorable
safety and tolerability profile maintained through up to 60 weeks of treatment with ontunisertib in Fibrostenosing Crohn’s disease
(FSCD) patients --
-- Low annualized
FSCD-related event rate of 3%, with one endoscopic balloon dilation (EBD) and no surgeries reported over the full treatment period --
-- Radiological
assessment shows trend for fibrotic stricture stabilization over treatment course --
-- Sustained
disease control observed across symptoms and disease activity scores in Open-Label Extension Study (OLE) --
-- Results support
initiation of global NOV-ERA Phase 2b study in FSCD in the coming months --
-- Company
to host webcast today at 8:30 a.m. Eastern Time --
Antwerp,
Belgium, October 1, 2026 – Agomab Therapeutics NV (‘Agomab’) a
clinical-stage biopharmaceutical company focused on fibro-inflammation, today announced positive results of the 48-week OLE portion of
the Phase 2a STENOVA trial evaluating ontunisertib in patients with FSCD, a severe manifestation of Crohn’s disease characterized by
progressive bowel fibrosis and intestinal strictures.
The OLE study (Part B)
evaluated long-term treatment with ontunisertib 200 mg BID on top of standard of care. Of the participants eligible to roll over into
the OLE study from the 12-week placebo-controlled Part A of STENOVA, 94% elected to enter the study (n=49).
The results demonstrated
a generally favorable long-term safety and tolerability profile of ontunisertib 200 mg BID for up to 60 weeks of treatment, as well as
maintenance of the gut-restricted pharmacokinetic (PK) profile observed in Part A of the trial. Sustained disease control,
with low symptoms and disease activity scores and radiological stricture stabilization, was also observed. Importantly, a low FSCD-related
annualized event rate of 3% was reported in patients treated with ontunisertib 200 mg BID up to 60 weeks.
“Fibrostenosing
Crohn’s disease remains one of the most significant unmet needs in fibro-inflammatory bowel disease, with no approved
therapies targeting the fibrotic component of the disease,” commented Florian Rieder, MD, Vice-Chair, Department of
Gastroenterology, Hepatology and Nutrition, Cleveland Clinic. “Beyond the favorable safety and tolerability profile, what
stands out in the OLE results is the sustained disease control as well as the low rate of interventions, with only one EBD and no
surgeries reported. Importantly, patients appeared to continue to do well on long-term treatment with ontunisertib, maintaining low
symptom levels and favorable outcomes on quality-of-life assessments. In a patient population often facing progressive bowel damage
and recurrent procedures, these combined findings point to the potential of ontunisertib to provide a meaningful clinical
benefit.”

Philippe
Wiesel, Chief Medical Officer of Agomab, added: “We are very pleased with the OLE results
announced today. The favorable long-term safety profile, maintenance of gut-restricted exposure and signals of sustained disease control
observed over up to 60 weeks of treatment provide strong support for the initiation of our global NOV-ERA Phase 2b study later this year.
Importantly, these data further support our belief that targeting fibro-inflammation through a differentiated anti-fibrotic mechanism
may address a key driver of disease progression that remains largely untreated today. We look forward to evaluating ontunisertib across
multiple dose levels in NOV-ERA as we continue to advance what we believe is a potentially novel therapeutic approach for people living
with fibro-inflammatory conditions.”
Topline STENOVA
OLE results
Safety and tolerability
profile
Ontunisertib 200
mg BID demonstrated a generally favorable safety and tolerability profile through up to 60 weeks of treatment. Five serious adverse events
were reported in four patients in Part B of the STENOVA study (48-week OLE); all of which were considered unrelated or unlikely
related to study treatment.
There were no signals
of cardiac injury, pro-inflammatory effects, vasculitis, liver toxicity or thrombotic events during the extended treatment period.
Pharmacokinetic
(PK) profile
Systemic exposure
of ontunisertib remained low throughout the OLE period and consistent with observations from the randomized-controlled 12-week portion
of STENOVA. Plasma concentrations remained well below IC50 levels, supporting the efficient gut-restricted pharmacokinetic
profile of ontunisertib and its differentiated approach to ALK5 inhibition.
Event rate
Only one FSCD-related
event, an EBD procedure, was reported during the study, corresponding to an annualized event rate of 3%. No patients progressed to surgery
during up to 60 weeks of ontunisertib 200 mg BID treatment. For reference, while not based on head-to-head studies, recent publications
on a comparable FSCD patient population receiving advanced therapies reported annualized event rates ranging from 23-35%.1,2,3,4
1
El Ouali et al. 2026, doi:10.1186/s12876-026-04815-4;
2
El Ouali et al. 2022, doi:10.1002/ueg2.12314; and
3
El Ouali et al. 2026, doi:10.1093/ecco-jcc/jjag038.
4 Cross-trial
comparisons are inherently limited due to differences in study design, patient populations, treatment regimens, endpoints and other factors,
and no conclusions regarding the relative efficacy or safety of ontunisertib should be drawn from such comparisons in the absence of
head-to-head clinical trials.

Imaging results
Magnetic resonance
enterography (MRE) assessments performed at Weeks 24 and 48 of the OLE study suggested radiological stabilization of fibrotic strictures
over the course of treatment with ontunisertib 200 mg BID. While patients receiving placebo showed a trend of radiological progression
during the 12-week Part A of the STENOVA study, the OLE results suggest that when switching to ontunisertib, those patients
stabilized and progressively caught up with those already exposed to ontunisertib in Part A.
Given the optional
nature of the Week 48 endoscopy assessment in the OLE study, the available data were too limited to allow for a reliable interpretation.
Patient-reported
outcomes
Patients maintained
a low symptom burden and disease activity throughout the OLE period, with sustained improvements observed across stricture-specific symptom
assessments, Crohn’s disease activity score (CDAI) and quality-of-life measures. At Week 48 of the OLE, 97% of evaluable patients were
in clinical remission as assessed by the CDAI score.
Next steps with ontunisertib: NOV-ERA
Phase 2b study
Agomab
recently completed regulatory filings for NOV-ERA, a global Phase 2b trial designed to evaluate ontunisertib in approximately 320 patients
with symptomatic FSCD and plans to initiate the study in the coming months. In NOV-ERA, participants
will be randomized to receive either ontunisertib at one of three dose levels (400 mg BID, 200 mg BID, and 100 mg BID), or a matching
placebo. Together with the favorable safety and tolerability profile previously demonstrated in Phase 1 at doses up to 400 mg BID, the
positive safety and tolerability findings of the OLE study provide strong support for the inclusion of a 400 mg BID treatment arm in
the NOV-ERA Phase 2b study.
Agomab intends
to present detailed STENOVA OLE results at a future scientific conference.
Ontunisertib
is an investigational drug and not approved by any regulatory authority. Its efficacy and safety have not been established.
Webcast Event
The Company will
hold a live webcast on Thursday, October 1, 2026 at 8:30 a.m. Eastern Time to discuss the STENOVA OLE results. Members
of the Agomab management team will be joined by key opinion leader Dr. Florian Rieder. To register for the live webcast and
replay, please visit the Agomab homepage.
About STENOVA
STENOVA, a first-in-indication
study, was a two-part Phase 2a trial in Crohn’s patients with symptomatic ileal strictures. Part A was a randomized,
double-blind, placebo-controlled study in a total of 103 participants. Participants were randomized to receive either 100mg QD or 200mg
BID of ontunisertib or placebo for 12 weeks on top of standard of care, including anti-inflammatory biologics. The study was conducted
in investigational sites in the USA, Canada and six European countries. The primary endpoint was the evaluation of the safety and tolerability
of ontunisertib in FSCD patients. Secondary endpoints included pharmacokinetics (PK) and target engagement. Exploratory endpoints included
the Simple Endoscopic Score of Crohn’s disease (SES-CD) and novel FSCD specific endpoints such as the Stricturing Patient Reported
Outcome (S-PRO) score and MRE. Eligible study participants who completed the double-blind 12-week treatment period could participate
in the OLE part of the STENOVA study (Part B) and receive ontunisertib 200mg BID for up to an additional 48 weeks. 49 patients
rolled over (94% of eligible patients of STENOVA Part A) and 37 patients completed the 48-week OLE Part B of
STENOVA. The OLE study assessed the long-term safety and PK profile of ontunisertib and explored the event rate and disease progression
in FSCD patients.

About NOV-ERA
The planned
NOV-ERA study is a randomized, double-blind, placebo-controlled, dose-ranging, multicenter Phase 2b trial to assess the efficacy and
safety of ontunisertib in participants diagnosed with symptomatic FSCD. The trial is expected to enroll up to 320 adult patients
globally. To be eligible for the trial, participants must have at least one naive or anastomotic endoscopically non-passable ileal
stricture, confirmed by a centrally read Simple Endoscopic Score for Crohn’s Disease (SES-CD). Upon study initiation,
participants will be randomized in a 1:1:1:1 ratio to receive either ontunisertib at one of three dose levels (400 mg, 200 mg, and
100 mg), or a matching placebo, administered twice daily (BID). The trial will consist of a 6-week screening period, a 52-week
treatment period, and a 2-week follow-up period. The primary endpoint is the proportion of patients achieving endoscopic passability
of the ileal index stricture at Week 24.
About Ontunisertib
Ontunisertib (AGMB-129)
is an oral small molecule GI-restricted inhibitor of ALK5 (or TGF-β RI) currently in clinical development for the treatment of Fibrostenosing
Crohn’s Disease (FSCD). TGF-β is a major driver of fibrosis. Ontunisertib is specifically designed to inhibit ALK5/TGF-β
in the GI-tract. Rapid first-pass metabolism in the liver prevents clinically relevant systemic exposure, potentially delivering an improved
safety profile over systemically available inhibitors in this class. Ontunisertib has received U.S. FDA Fast Track Designation.
About Agomab
Agomab is a clinical-stage
biopharmaceutical company focused on developing novel disease-modifying therapies for fibro-inflammatory diseases with high unmet medical
need. Agomab’s product candidates are designed to target established, potent pathways and utilize organ-restricted
approaches, with the aim of increasing efficacy while minimizing safety liabilities. Fostering a culture of excellence, Agomab’s mission
is to pioneer therapeutics that aim to resolve fibro-inflammation and restore organ function to enable people with these disorders to
live fuller and healthier lives.
Cautionary Note
regarding Forward-Looking Statements
This press release
includes certain disclosures that contain “forward-looking statements” within the meaning of Section 27A of the Securities
Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. Forward-looking statements are often
identified by terms such as “continue,” “anticipate,” “believe,” “could,” “estimate,”
“expect,” “goal,” “intend,” “look forward to,” “may,” “plan,” “potential,”
“predict,” “project,” “should,” “will,” “would” and similar expressions. “Forward-looking
statements” include, without limitation, statements regarding the potential of ontunisertib for Fibrostenosing Crohn’s disease,
the expected initiation of the NOV-ERA Phase 2b study, and our interactions with regulatory authorities. Forward-looking statements are
based on Agomab’s current expectations and are subject to inherent uncertainties, risks and assumptions that are difficult to predict.
Factors that could cause actual results to differ include, but are not limited to, risks and uncertainties related to the results of
our clinical trials; expectations regarding the inherent uncertainties associated with the development of novel drug therapies; preclinical
and clinical trial and product development activities and regulatory approval requirements for product candidates; the impact of governmental
laws and regulations on our business; and disruptions caused by our reliance on third party suppliers and service providers. These and
other risks and uncertainties are described more fully in our filings and reports with the SEC, including in our most recent annual report
on Form 20-F filed with the SEC and our subsequent filings and reports filed with the SEC. Forward-looking statements contained
in this announcement are made as of this date, and Agomab undertakes no duty to update such information except as required under applicable
law. Readers should not rely upon the information in this announcement as current or accurate after its publication date.
Contacts
Investors
Sofie Van Gijsel
VP of Investor
Relations
E-Mail: sofie.vangijsel@agomab.com
Phone: +1 781 296
1143
Media
Gretchen Schweitzer
Trophic Communications
E-Mail: agomab@trophic.eu
Phone: +49 172
861 8540