The presentation will present results from a translational analysis based on patients from the ETOP/EORTC Phase III SPLENDOUR trial. The study was conducted as a collaboration between CHOSA and ETOP/EORTC and evaluates the association between CHOSA's Platin-DRP score and clinical outcomes in platinum-treated advanced NSCLC. Full details of the data will be disclosed at the opening of the Poster Session in a separate announcement.

The abstract is authored by an international group of investigators from CHOSA, ETOP and leading academic institutions, including Professor Stephen Finn of ETOP, Professor Solange Peters and Professor Rolf Stahel of ETOP, and Professor Fred Hirsch of Mount Sinai, New York. Data will be presented by Professor. Stephen Finn, Chair of the ETOP Translational Research Working Group.

Title: 459P - "mRNA profile to predict platin sensitivity in NSCLC: A translational analysis of the ETOP/EORTC SPLENDOUR Trial"

Poster Display Session 1:  Thursday, 26 March 2026, 13:00-14:00 CET

Topic: Translational Research

CHOSA Oncology will host an online webinar on Thursday, March 26 at 5pm CET, where you will learn more about CHOSA and the company's new data, followed by a hosted Q&A session. You can sign up here: Link - Welcome!

Further information on the presentation is available through the official ELCC 2026 program page: Link
 

For additional information contact:

Peter Buhl Jensen, CEO

peter@chosa.bio

+ 45 21 60 89 22

Background

Cisplatin and its sister molecule carboplatin have been cornerstones in lung cancer therapy for decades. Despite advances in immunotherapy, platinum drugs remain critical in treatment regimens, including combinations with PD-1/L1 inhibitors. While numerous efforts to predict cisplatin efficacy have failed, the Platin-DRP, based on a 205-gene biomarker signature, has shown promising results in other settings, including adjuvant therapy in NSCLC and progression-free survival in breast cancer. As previously announced, CHOSA is also exploring the predictive potential of Platin-DRP in those treated with carboplatin in lung cancer. Data from the SPLENDOUR trial provides a unique opportunity to validate this tool in a large cohort and potentially confirm its utility across both drugs. Future research will also aim to determine whether Platin-DRP can predict the effectiveness of platinum drugs combined with PD-1/L1 inhibitors. CHOSA Oncology AB is an oncology biotechnology company led by an experienced international team with expertise in oncology, drug development, clinical trials, regulatory affairs, and business development. CHOSA intends to enter into partnership or sublicensing agreements for LiPlaCis® and the DRP®.

About ETOP IBCSG Partners Foundation

The ETOP IBCSG Partners Foundation is a not-for-profit international academic research organization based in Berne, Switzerland. Established on July 1, 2021, through the merger of the European Thoracic Oncology Platform (ETOP) and the International Breast Cancer Study Group (IBCSG), the foundation aims to promote scientific exchange and advance cancer research, particularly in thoracic and breast cancers.

The foundation's mission is to answer questions that improve patients' lives, with a vision of enhancing scientific exchange on a global scale. It achieves this by implementing and promoting clinical and translational research studies, fostering collaboration among international investigators, and organizing educational events such as annual meetings and residential workshops.

About EORTC

The European Organisation for Research and Treatment of Cancer (EORTC) is a non-governmental, non-profit organisation, which unites clinical cancer research experts, throughout Europe, to define better treatments for cancer patients to prolong survival and improve quality of life. Spanning from translational to large, prospective, multi-centre, phase III clinical trials that evaluate new therapies and treatment strategies as well as patient quality of life, its activities are coordinated from EORTC Headquarters, a unique international clinical research infrastructure, based in Brussels, Belgium.

About Platin-DRP, a test to predict if cisplatin treatment is likely to be successful

CHOSA is focused on its Platin-DRP® drug response predictor, to which it holds worldwide rights. Platinlatin-DRP is a validated test designed to help identify patients most likely to benefit from cis- and carboplatin treatment. Breast: Strong phase 2b data in metastatic breast cancer have shown that patients selected by DRP® responded better to treatment, had longer progression-free survival, and may also have achieved longer overall survival than patients identified as unlikely to respond well. Lung: Platin-DRP has also demonstrated its ability to predict the benefit of cisplatin in lung cancer. Cisplatin treatment after surgery remains a gold standard that can improve cure rates, but doctors have not had a validated tool to identify which patients are most likely to benefit. This is where Platin-DRP may become a game changer, particularly in newer neoadjuvant settings where immunotherapy has shown high efficacy in combination with platinum doublets. Platin-DRP was validated in a blinded retrospective study in two lung cancer patient cohorts receiving cisplatin after surgery to eliminate residual tumour cells. Patients with the 10% highest scores had a 3-year survival of 90%, whereas patients with the lowest 10% scores had a 3-year survival of only 40%.¹

Immunotherapy Cisplatin has often been shown to activate the immune system, potentially making "cold" tumours more susceptible to PD-1 inhibitors. This synergy may be important not only in lung cancer, but also in bladder cancer and head & neck cancer. In the growing PD-1 inhibitor market, CHOSA's approach may offer the ability to predict whether platin can provide synergy with PD-1 inhibition, potentially creating a meaningful advantage for treatment selection and future partners.

1) Buhl et al PLOS One doi: 10.1371/journal.pone0194609

DRP® is a registered trademark of Allarity Therapeutics, Inc., and is used under license granted to CHOSA. LiPlaCis is in-licensed from Allarity Therapeutics Ltd (previous Oncology Venture ApS) and LiPlasome Pharma ApS.