SoftOx Solutions AS: SIS-03 DOSE-ESCALATION PHASE COMPLETED AND INITIATION OF PROOF-OF-CONCEPT PHASE

08 Jun 2026 09:00 CEST

SIS-03 advances toward the proof-of-concept patient phase in chronic airway
infections

Oslo/Copenhagen: SoftOx Solutions AS (“SoftOx”), a clinical-stage pharmaceutical
company developing a novel anti-infective therapy for airway infections, today
announces that the dose-escalation part of the SIS-03 Phase 2a clinical program
has been completed. Following completion of this part of the trial, the Company
has initiated the proof-of-concept (“PoC”) patient phase of the program. The
objective of SIS-03 is to evaluate SoftOx Inhalation Solution (“SIS”) as an
inhaled anti-infective therapy for chronic airway infections in patients with
cystic fibrosis.

The completed dose-escalation part was designed to confirm safety and
tolerability at increasing dose levels in healthy volunteers and to support
dose-level selection for the PoC patient phase of the trial. The trial was
approved by the Danish Medicines Agency in December 2025, and the first
volunteer was enrolled in the initial dose-escalation part of the study in March
2026. This first part of SIS-03 is now fully completed.

TRANSITION INTO THE PROOF-OF-CONCEPT PATIENT PHASE
“It is very satisfying to see the SIS-03 trial advancing as planned. With the
dose-escalation part now completed, we are eager to move into the next phase,
where we will learn much more about how SIS performs in a highly relevant
patient population suffering from chronic airway infections. Patients with
cystic fibrosis frequently experience chronic lung infections that may become
resistant to currently available therapies, and we believe SIS has the potential
to make a meaningful difference in a patient population where there remains a
significant unmet medical need,” stated Thomas Bjarnsholt, CEO of SoftOx.

The initiation of the PoC patient phase marks an important next step for the
SIS-03 program. This upcoming phase is designed to assess microbiological
signals relevant to establishing proof-of-concept for SIS, including key data on
bacterial load reduction in patients’ airways.

A separate topline safety update from the dose-escalation part of SIS-03 is
expected to be communicated when the relevant data analysis has been completed.
Therefore, no detailed safety or tolerability data are disclosed in this
announcement.

The SIS-03 clinical trial program is being conducted together with
Rigshospitalet in Copenhagen, Denmark, and the upcoming proof-of-concept phase
is expected to conclude in H1 2027.

POTENTIAL COMMERCIAL RELEVANCE IN CHRONIC AIRWAYS INFECTIONS
Based on Company estimates, approximately 13,000 patients with cystic fibrosis
across the US and EU4+UK receive chronic inhaled antibiotic therapy,
representing a market of more than USD 600 million annually. SoftOx believes
SIS’s mechanism may also be relevant to non-CF bronchiectasis, a significantly
larger indication affecting approximately 445,000 patients, with a potential
market opportunity exceeding USD 5 billion.

ABOUT SIS
SoftOx Solutions AS is developing SIS, a novel inhaled anti-infective therapy
for respiratory infections in the airways and lungs. SIS targets
biofilm-associated infections through a patented, non-antibiotic mechanism
designed to reduce the risk of resistance development. Delivered by nebulizer,
SIS is being developed to address bacterial, viral, and fungal pathogens through
local delivery directly at the site of infection, without systemic exposure to
the remainder of the human body. Its broad pathogen relevance positions SIS as a
distinct therapeutic in respiratory infections.

ABOUT SOFTOX SOLUTIONS AS
SoftOx Solutions AS (ticker: SOFTX) is a clinical-stage pharmaceutical company
developing SIS (SoftOx Inhalation Solution), a novel inhaled anti-infective
therapy for the treatment of respiratory infections in the airways and lungs.
The Company is listed on Euronext Growth Oslo.

FOR MORE INFORMATION, PLEASE CONTACT
Ulrik Spork, Chairman of the Board, SoftOx Solutions AS, +45 31 38 83 87
Thomas Bjarnsholt, CEO, SoftOx Solutions AS, +45 20 65 98 88
Mail: ir@soft-ox.com

This information is subject to the disclosure requirements pursuant to section
5-12 of the Norwegian Securities Trading Act.

More information:
Access the news on Oslo Bors NewsWeb site

675595_Press Release Dose Escalation.pdf