Chosa Oncology AB: CHOSA - The market now doubles for Platin-DRP®, which predicts overall survival in lung cancer patients based on NanoString data

These results build on CHOSA's previously announced data using the Affymetrix assay platform from the ETOP/EORTC SPLENDOUR study (press release, September 30, 2025), in which CHOSA and the European Thoracic Oncology Platform (ETOP) reported that the Platin-DRP® robustly predicts clinical benefit from carboplatin- and cisplatin-based chemotherapy.

The new NanoString analysis further strengthens the technical and clinical evidence across platforms, demonstrating a high correlation between NanoString-based scores and the original Platin-DRP® signature. With the ability to work in NanoString too, the relevant market for the Platin-DRP more than doubles according to Genomic Biomarkers Market Size & Share Analysis - Growth Trends & Forecasts (2025 - 2030) from Mordor Intelligence.

In the NanoString study, higher Platin-DRP® scores were significantly predicting longer overall survival in both the carboplatin cohort and the overall platinum-treated population. As seen in many modern oncology datasets, objective response rates were not significantly associated with the transcriptomic score, underlining that survival is the most clinically relevant endpoint for prediction of long-term treatment benefit.

Peter Buhl Jensen, CEO of CHOSA Oncology, commented:
"These new findings represent another important milestone for CHOSA. They confirm that our biomarker technology performs consistently across platforms and continues to show clinical relevance in lung cancer." Said Peter Buhl Jensen "Together with the other positive SPLENDOUR results announced earlier this year, this strengthens our confidence as we progress Platin-DRP® toward broader clinical use and regulatory pathways" he further commented.

The company is engaging in regulatory discussions and preparing for commercialization including further analytical validation and alignment with international lung cancer experts.

In CHOSA's collaboration with ETOP/EORTC, the Platin-DRP® has now been validated across multiple datasets and platforms. In the SPLENDOUR study, the biomarker predicted survival in lung cancer patients treated with both cisplatin and carboplatin. Subsequent NanoString analysis confirmed that higher Platin-DRP® scores were significantly predicting longer overall survival in both the carboplatin and the combined platin scores.

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 chemotherapy 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 Cisplatin-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 the Cisplatin-DRP not only in cisplatin-treated patients but also 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, potentially confirming its utility across both drugs. Future research will aim to determine whether the Cisplatin-DRP can predict the effectiveness of combinations of platinum drugs with PD-1/L1 inhibitors.

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.

CHOSA in short

CHOSA Oncology AB is an oncology biotechnology company led by a proven international team with veteran specialists in oncology; drug development; running clinical trials; regulatory expertise; and business development. CHOSA intends to enter into agreements for partnership or sublicensing of LiPlaCis® and the DRP®.

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

CHOSA is focused on late-stage clinical development of LiPlaCis® and its DRP® drug response predictor to which it has worldwide rights. The cisplatin DRP is the only proven test to foresee and thereby select who to treat and who will benefit from cisplatin. Breast: We have strong phase 2b data in metastatic breast cancer, demonstrating that patients selected by DRP® responded better to treatment; have longer progression-free survival; and maybe even an overall longer total survival than those patients who were identified as unlikely to respond well to the treatment.

Lung: The cisplatin DRP has previously shown its ability to foresee the value of cisplatin therapy in lung cancer. Cisplatin therapy after surgery is a gold standard that increases lung cancer cure, but not always, and until now the doctors do not know who will benefit from cisplatin and who should have something else. This is where the cisplatin DRP is a potential game changer, especially in new neoadjuvant treatment where immunotherapy obtains high efficacy rates when combined with cisplatin doubles. Cisplatin DRP was validated in a blinded retrospective study in two lung cancer patient cohorts receiving cisplatin after surgery to kill remaining tumor cells. Thus, patients with the 10% highest scores had a 3-year survival of 90% whereas the patients with the lowest 10% score had much lower survival with only 40% surviving 3 years1.

Immunotherapy There is a new development that adds further value to our DRP. Cisplatin has often been shown to activate the immune system (making cold tumors hot), which makes tumors susceptible to PD1 inhibitors. This synergy is particularly important but not limited to the treatment of lung cancer, bladder cancer, and head and neck cancer. In the ever-growing PD1 inhibitor market, where competition is fierce, our company stands out with the ability to predict if cisplatin will provide synergy with PD1. This can give the PD1 selling companies a significant competitive advantage.

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.