e-Poster Presentation Clinical Oncology Society of Australia Annual Scientific Meeting 2021

CRESTONE – Clinical Study of REsponse to Seribantumab in Tumours with NEuregulin-1 (NRG1) Fusions – A Phase 2 Study of the anti-HER3 monoclonal antibody for Advanced or Metastatic Solid Tumours (MoST CRESTONE in Australia) (#405)

Subo Thavaneswaran, BSc, MBBS (Honours), FRACP, MMed PhD 1 2 , Lucille Sebastian, BSc (Hons), PhD 2 , Sarah Finlayson, BAdvSc (Hons), Grad Cert Pharm Med 2 , Jayesh Desai 3 , Ken O'Byrne 4 , Rosemary Harrup, MBBS, FRCPA, FRACP 5 , Mandy L Ballinger, BSc (Hons), MGenCouns, PhD 1 6 , Frank Lin, MB ChB, PhD, FRACP 1 2 , John P Grady 1 , Maya Kansara 1 6 , John Simes, BSc(Med) MBBS SM FRACP MD 2 , Shawn M Leland, PharmD, RPh 7 , Valerie M Jansen, MD, PhD 7 , Amy C Cavers 7 , David M Thomas 1 6
  1. The Kinghorn Cancer Centre, Garvan Institute of Medical Research, Sydney, NSW, Australia
  2. NHMRC Clinical Trials Centre, University of Sydney, Sydney, NSW, Australia
  3. Department of Medical Oncology, Peter MacCallum Cancer Centre, Melbourne, VIC, Australia
  4. Princess Alexandra Hospital, Brisbane, QLD, Australia
  5. Royal Hobart Hospital, Hobart, Australia
  6. Faculty of Medicine, St Vincent’s Clinical School, University of NSW, Sydney, NSW, Australia
  7. Elevation Oncology, New York City, NY, United States

Background

Neuregulin-1 (NRG1) gene fusions are rare oncogenic drivers found in 0.2% of solid cancers, including lung, pancreatic, and 10 other tumour types to date. NRG1 is the predominant ligand of HER3 and NRG1 fusion proteins with an active EGF-like domain driving tumourigenesis and proliferation through aberrant HER3 activation. Importantly, NRG1 fusions often demonstrate mutual exclusivity with other driver alterations.

NRG1 fusions have been correlated with worse Overall Survival (OS), Disease-Free Survival (DFS) and poor response to treatment with chemotherapy and chemo-IO. Inhibition of HER3, preventing dimerisation with its partners, specifically NRG1 in NRG1 gene fusion positive cancers, represents a novel therapeutic approach.

Seribantumab is a fully human IgG2 monoclonal antibody targeting HER3, uniquely inhibiting NRG1-dependent activation of HER3, HER3-HER2 dimerisation and downstream signaling of PI3K/AKT and MAPK pathways. In NRG1 fusion-positive patient-derived xenografts, seribantumab treatment resulted in 50‒100% tumour reduction across multiple cancers and fusion partners. Clinical safety profile of seribantumab is established in monotherapy and combination studies in >800 patients.

Methods

CRESTONE is a multicenter open-label, phase 2 trial of intravenous seribantumab in patients with NRG1 gene fusion-positive, advanced solid tumours, having progressed on, or unsuitable for standard therapies. Australian patients will be identified through the Molecular Screening and Therapeutics (MoST) program with central confirmation after enrollment. MoST CRESTONE refers to the subset of 16 Australian patients who will receive seribantumab treatment and contribute to the Global CRESTONE study.

Objectives

The primary endpoint is Overall Response Rate by RECIST. Secondary endpoints include Duration of Response, safety, PFS, OS and Clinical Benefit Rate. An interim analysis is planned following enrollment of 20 patients in the overall global CRESTONE trial and treated at the 3g weekly IV schedule. 

CRESTONE (NCT04383210) is accruing patients in the US with MoST CRESTONE in Australia and Canadian sites to open Q4 2021.