OncoHost's PROphet Model Shows Promise for Optimizing Melanoma Treatment Selection at ESMO 2025
Key Insights
OncoHost (search)'s PROphet plasma proteomics model successfully stratified 248 metastatic melanoma (search) patients, with PROphet POSITIVE patients showing significant survival advantage over PROphet NEGATIVE patients (HR = 0.42, p < 0.001).
The study suggests PROphet POSITIVE patients (66% of cohort) achieve comparable survival with anti-PD1 (search) monotherapy versus combination therapy, potentially sparing unnecessary toxicity from combination regimens.
PROphet NEGATIVE patients demonstrated a trend toward improved survival with anti-PD1 (search) plus anti-CTLA4 (search) combination therapy (HR = 0.64, p = 0.065).
OncoHost (search) announced that its latest research on plasma proteomics-based treatment selection for metastatic melanoma (search) has been accepted for poster presentation at the European Society for Medical Oncology (ESMO) 2025 Congress, taking place October 17-21 in Berlin, Germany. The study explores the potential of the company's PROphet model, originally developed and validated in non-small cell lung cancer (search) (NSCLC (search)), to inform treatment decisions in melanoma, where biomarkers to guide clinical decisions remain limited.
Study Design and Patient Population
The real-world prospective observational study analyzed pre-treatment plasma samples from 248 patients with metastatic melanoma (search). Patients were treated with either anti-PD1 (search) monotherapy (pembrolizumab or nivolumab) or anti-PD1 plus anti-CTLA4 (search) combination therapy (ipilimumab plus nivolumab). The PROphet platform leverages a panel of 388 Resistance-Associated Proteins (RAPs) to compute the probability of clinical benefit and stratify patients as PROphet POSITIVE or PROphet NEGATIVE.
Key Clinical Findings
The study demonstrated significant prognostic power, with PROphet POSITIVE patients showing a substantial survival advantage over PROphet NEGATIVE patients (HR = 0.42, p < 0.001). The strongest predictive effect was observed in patients treated with anti-PD1 (search) monotherapy, underscoring the model's utility in this therapeutic setting.
Multivariate analysis confirmed that PROphet remained statistically significant even after adjusting for lactate dehydrogenase (LDH), age, sex, and other clinical variables (HR = 0.30, p = 0.04), establishing it as an independent prognostic factor.
Treatment Optimization Insights
The research revealed important treatment guidance implications. PROphet POSITIVE patients, representing 66% of the study cohort, achieved comparable survival outcomes with anti-PD1 (search) monotherapy and anti-PD1 plus anti-CTLA4 (search) combination therapy (HR = 0.9, p = 0.35). This finding suggests that monotherapy may be sufficient for this patient population, potentially sparing them from unnecessary toxicity associated with combination regimens.
Conversely, PROphet NEGATIVE patients demonstrated a trend toward improved survival with the combination therapy approach (HR = 0.64, p = 0.065), indicating this population may benefit from more intensive treatment strategies.
Clinical Significance
"Selecting the right treatment modality for melanoma patients remains a significant clinical challenge," said Michal Harel, PhD, VP Translational Medicine at OncoHost (search). "Our findings demonstrate how plasma proteomics can provide actionable insights that inform treatment decisions and bring us closer to truly personalized care for patients facing melanoma."
The research will be presented by Ryan Sullivan, MD, from Massachusetts General Hospital, Boston, during the melanoma and other skin tumours session on October 18, 2025 (Poster Number: 1680P).
Platform Background
PROphet is OncoHost (search)'s proprietary plasma-based proteomic pattern analysis tool, initially developed for NSCLC (search) where it has demonstrated predictive value for patient outcomes with anti-PD(L)1 (search)-based therapy. The platform uses a single blood sample to guide first-line immunotherapy decision-making and has shown significant effects on overall survival in its initial NSCLC application.