CHOSA's Platinum Drug Predictor Shows Promise Across Multiple Cancer Types in Clinical Validation Studies
Key Insights
CHOSA Oncology (search) announced positive results from its collaboration with ETOP (search)/EORTC, demonstrating that the Platin-DRP® biomarker successfully predicted treatment outcomes in advanced non-small cell lung cancer patients.
The 205-gene predictor showed statistically significant prediction of progression-free survival for cisplatin and overall survival for carboplatin in the SPLENDOUR trial analysis.
Additional validation data presented at ESMO 2025 confirmed the predictor's ability to identify metastatic breast cancer patients likely to benefit from carboplatin therapy.
CHOSA Oncology (search) AB has announced positive results from multiple clinical validation studies of its Platin-DRP® biomarker, demonstrating the predictor's ability to identify cancer patients most likely to benefit from platinum-based chemotherapy across lung and breast cancers.
Lung Cancer Validation in SPLENDOUR Trial
The company's collaboration with the European Thoracic Oncology Platform (ETOP (search)) and European Organisation for Research and Treatment of Cancer (EORTC) analyzed tumor samples from the SPLENDOUR trial, which included 514 patients with advanced non-small cell lung cancer (NSCLC) receiving platinum-based therapy.
Following rigorous curation of tumor tissue, the analysis included 28 patients treated with cisplatin and 54 with carboplatin. For cisplatin, the Platin-DRP® reached its primary endpoint and showed statistically significant prediction of progression-free survival (PFS) with higher PFS associated with higher Platin-DRP® scores, overall and across two of the three thresholds tested.
For carboplatin, the Platin-DRP® showed statistically significant prediction of overall survival with higher OS associated with higher Platin-DRP® scores, overall and across all tested thresholds. Additionally, a positive trend was observed for prediction of PFS.
"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 Solange Peters and Rolf Stahel, ETOP (search) lung cancer experts. "The CHOSA collaboration provides preliminary support for the potential of Platin-DRP® in daily practice."
Breast Cancer Data at ESMO 2025
At the ESMO 2025 Annual Congress in Berlin, CHOSA presented additional validation data demonstrating the predictor's utility in metastatic breast cancer. The study analyzed gene expression data from 20 metastatic breast cancer patients treated with carboplatin within the Danish Breast Cancer Group (DBCG) cohort.
Key findings showed that patients with high DRP scores (>50) experienced significantly longer time to progression with a median of 6.5 months compared to those with low scores (≤50) who had a median of 2.1 months. A 50-point increase in DRP score was associated with a hazard ratio of 0.31 (one-sided p = 0.03), indicating a statistically significant reduction in risk of progression.
Clinical Significance and Market Impact
"Our data demonstrate that the cisplatin-derived DRP® can predict benefit not only from cisplatin but also from carboplatin," said Peter Buhl Jensen, CEO of CHOSA Oncology (search). "This expands the clinical and commercial potential of the Platin-DRP® as a precision-oncology tool for selecting the right patients for platinum therapy - one of the most widely used chemotherapy classes worldwide. Indeed almost 50% of cancer patients receiving chemotherapy are receiving a platinum base regimen."
The 205-gene biomarker signature has now demonstrated promising results across multiple settings, including improved outcomes in adjuvant NSCLC therapy and progression-free survival in breast cancer. These findings support and extend prior validation of the Platin-DRP® in-licensed from Allarity Therapeutics Inc., including two retrospective NSCLC studies and one prospective metastatic breast cancer study.
Regulatory Path Forward
CHOSA expects to present the full data at upcoming scientific conferences and will submit the results for peer-reviewed publication. The company plans to initiate interactions with the FDA and EMA to explore a path towards marketing approval.
"Lung cancer remains one of the deadliest cancers worldwide. This project demonstrates that our predictor can identify patients more likely to benefit from cisplatin or carboplatin," said Jensen. "The ability to leverage high-quality biopsies from a large, independent trial has saved us years of development and brought us significantly closer to commercialization."
Broader Treatment Context
Cisplatin and carboplatin remain essential components of treatment regimens, including combinations with PD-1 (search)/L1 inhibitors such as Keytruda and Opdivo. While these platinum combination therapies have revolutionized lung cancer treatment, only 50% of patients benefit from these new regimens.
In breast cancer, platinum drugs work especially well for triple-negative breast cancer (TNBC), which comprises about 20% of breast cancer cases. Current neoadjuvant approaches combining platinum-based chemotherapy and immunotherapy achieve complete pathological response rates of 60-65% in TNBC patients, but this benefit is primarily seen in patients whose cancer responds well to treatment.
The Platin-DRP® represents the fifth independent clinical validation of CHOSA's cisplatin predictor, further supporting its potential to guide individualized treatment decisions across multiple cancer types and platinum-based regimens.