Abstract A087: BI KRASmulti, a first-in-class, orally bioavailable and direct inhibitor of diverse oncogenic KRAS variants drives tumor regression in KRAS G12V-driven preclinical models

Abstract

Abstract Alterations of KRAS are found in approximately one in seven of all human tumors, making KRAS one of the most prevalent oncogenic drivers. Gain-of-function missense mutations in KRAS, leading to its aberrant activation, are found in ~90% of pancreatic cancer, ~40% of colorectal cancer and ~30% of lung adenocarcinoma, with KRASG12V mutations accounting for ~28%, 9% and 6% of the cases, respectively. The poor outcome associated with these tumor types, particularly pancreatic cancer, as well as the lack of targeted inhibitors for KRASG12V calls for the urgent need to identify therapies able to effectively address the KRASG12V mutant allele. BI 3706674 is a novel, potent and orally available small molecule inhibitor of the KRAS oncogene. BI 3706674 binds non-covalently to multiple KRAS mutant alleles, including KRASG12V, in the GDP-bound state, and blocks downstream oncogenic signalling. Here, we show that BI 3706674 has a strong anti-proliferative activity in a panel of KRASG12V mutant cancer cell lines in vitro, along with significant pharmacodynamic (PD) biomarker modulation (including inhibition of ERK1/2 phosphorylation and down-regulation of DUSP6 mRNA).In vivo, a twice daily oral dose of 30 mg/kg was well-tolerated, while inducing tumour regression in several mutant KRASG12V cell line-derived and patient-derived xenograft (CDX and PDX) models across multiple different human tumor types. We have selected different non-small cell lung cancer xenograft models for extensive PK/PD/efficacy analysis in vivo. Results of the ongoing analysis will be shared. Feedback activation of upstream signalling pathways including receptor tyrosine kinase, such as the EGFR, has been suggested to be able to limit the efficacy of GDP-KRAS targeting compounds in preclinical studies. These findings have been supported by clinical combination trials involving KRASG12C inhibitors such as Adagrasib and Sotorasib and anti-EGFR modalities. We demonstrate for the first time that combination with anti-EGFR antibodies (e.g., Cetuximab) potently enhances the response observed with BI 3706674 in settings of KRASG12V mutant pancreatic, colorectal, and lung cancer. The deeper response observed upon combination of BI 3706674 with Cetuximab across multiple xenograft models provides a strong rationale for the clinical investigation of this combination therapy. Moreover, we utilize an ex vivo organoid platform to rapidly identify novel drug combinations with BI 3706674 that can potentially translate to clinical trials. The KRASmulti inhibitor BI 3706674 is currently undergoing IND enabling studies. Single agent dose escalation will include patients with cancers harbouring KRASG12V mutations. Citation Format: David H Peng, Antonio Tedeschi, Lorenz Herdeis, Fabio Savarese, Francesca Rocchetti, Popow Johannes, Heinrich J Huber, Nicola Melillo, Jake Dickinson, Hitesh B Mistry, Birgit Wilding, Matthias Treu, Julian Fuchs, Joachim Broker, Tobias Wunberg, Fiorella Schischlik, Jesse Lipp, Vandhana Ramamoorthy, Joseph R Daniele, Scott Kopetz, Michael Kim, Don L Gibbons, Christopher P Vellano, Joseph R Marszalek, Timothy P Heffernan, Darryl McConnell, Mark Pearson, Norbert Kraut, Dorothea Rudolph. BI KRASmulti, a first-in-class, orally bioavailable and direct inhibitor of diverse oncogenic KRAS variants drives tumor regression in KRAS G12V-driven preclinical models [abstract]. In: Proceedings of the AACR-NCI-EORTC Virtual International Conference on Molecular Targets and Cancer Therapeutics; 2023 Oct 11-15; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2023;22(12 Suppl):Abstract nr A087.