The project evaluates CHOSA's Platin-DRP® in patients with advanced non-small cell lung cancer (NSCLC) treated with platinum-based chemotherapy in the Phase III SPLENDOUR trial.

The translational analysis included 82 patients, of whom 28 were treated with cisplatin and 54 with carboplatin.

The data presented at ELCC showed that, in the pooled cohort, higher Platin-DRP® scores were associated with statistically significant improvement in both progression-free survival (PFS) and overall survival (OS). Importantly, overall survival showed the strongest association, with a hazard ratio of 0.602 (p = 0.011) for 50-point increase of DRP score. For progression-free survival, the hazard ratio was 0.697 (p = 0.029).

Using the predefined 50% threshold in the pooled cohort, patients with high Platin-DRP® scores had a median overall survival of 16.9 months, compared to 5.5 months for patients with low scores.

The analysis further showed that there was no significant interaction between chemotherapy regimen (cisplatin versus carboplatin) and DRP score for any endpoint, supporting the potential applicability of the biomarker across both platinum agents. No significant association was observed between DRP score and response rate.

These data build on the Company's previously announced findings and further support the clinical relevance of Platin-DRP® in advanced NSCLC. The ELCC presentation is based on a retrospective blinded translational analysis conducted under a prospective-retrospective design using material from the randomized Phase III SPLENDOUR study.

"Platinum compounds remain the backbone of therapy in advanced NSCLC, yet there are no biomarkers allowing to predict their efficacy in clinical use today," said Professors Stephen Finn, Solange Peters, Rolf Stahel and Fred Hirsch, key lung cancer experts. "In the absence of validated predictive biomarkers for cis- and carboplatin, these results suggest that DRP may offer guidance in both clinical trials and practice.

"Overall survival is the most important endpoint for patients and clinicians, and we are very encouraged to see this strong and statistically significant association between higher Platin-DRP® scores and longer survival in advanced NSCLC," said Peter Buhl Jensen, MD, DMSc, CEO of CHOSA. "To see median overall survival of 16.9 months in the high-score group is a doubling and is clinically highly meaningful and in fact the patients only surviving 5.5 month did not benefit. These data strengthen our confidence that Platin-DRP® can become an important tool to help guide platinum treatment in lung cancer and support our continued path toward regulatory and commercial development."

The poster concludes that high DRP scores were associated with improved PFS and OS in platinum-treated advanced NSCLC and that, in the absence of validated predictive biomarkers for cis- and carboplatin, the results suggest that Platin-DRP® may offer guidance in both clinical trials and practice. Further validation studies are ongoing, including evaluation of the predictive role of the biomarker in platinum plus immunotherapy settings.

The abstract was authored by an international group of investigators from CHOSA, ETOP and leading academic institutions, including Professors Stephen Finn, Solange Peters, Rolf Stahel, and Professor Fred R. Hirsch.

The data were presented today in poster presentation 459P - "mRNA profile to predict platin sensitivity in NSCLC: A translational analysis of the ETOP/EORTC SPLENDOUR Trial" by Professor Stephen Finn, Chair of the ETOP Translational Research Working Group.

Congress: European Lung Cancer Congress (ELCC) 2026, Copenhagen, Denmark, 25-28 March 2026. Poster details:

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, 26 March at 17:00 CET, where management will present CHOSA and the new data, followed by a hosted Q&A session. Registration Link

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

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.