Correlation of NGS <i>KRAS</i> mutant allele frequency with digital PCR <i>KRAS</i> mutant allele frequency detected in the appropriate multiplex assay for FFPE tissue DNA and cell line gDNA samples.

<p>Correlation of NGS <i>KRAS</i> mutant allele frequency with digital PCR <i>KRAS</i> mutant allele frequency detected in the appropriate multiplex assay for FFPE tissue DNA and cell line gDNA samples.</p

<i>KRAS</i> mutations observed in human NSCLC in order of decreasing frequency (http://www.sanger.co.uk/cosmic; accessed 14^th July 2015).

<p><i>KRAS</i> mutations observed in human NSCLC in order of decreasing frequency (<a href="http://www.sanger.co.uk/cosmic" target="_blank">http://www.sanger.co.uk/cosmic</a>; accessed 14^th July 2015).</p

<i>KRAS</i> mutations observed in human cancer in order of decreasing frequency (http://www.sanger.co.uk/cosmic; accessed 14^th July 2015).

<p><i>KRAS</i> mutations observed in human cancer in order of decreasing frequency (<a href="http://www.sanger.co.uk/cosmic" target="_blank">http://www.sanger.co.uk/cosmic</a>; accessed 14^th July 2015).</p

<i>KRAS</i> duplex assays at optimal annealing temperature.

<p>Droplet populations observed for each duplex assay tested with wild-type and relevant mutant cell line gDNA or oligonucleotide at the optimal annealing temperature e.g. G12V panel top left shows droplet populations seen with WT for G12V assay, G12V assay, NCI-H727 gDNA and NCI-H1975 gDNA present. HEX amplitude is up to 6000 on the x axis and FAM amplitude up to 11000 on the y-axis of each panel. Key: Black drops- empty droplets, blue- mutant DNA FAM positive droplets, green- wild-type DNA HEX positive droplets, brown—wild-type and mutant DNA double positive droplets.</p

<i>KRAS</i> mutant FFPE tissue DNA analysis using multiplex and duplex assays to detect <i>KRAS</i> mutant clones.

<p>All samples, except for S011, were analysed with multiplexes A, B and C (upper panels) and the <i>KRAS</i> mutation detected was subsequently confirmed with the appropriate duplex assay (lower panels). Mutant DNA droplet populations are highlighted with a red dashed square. Droplet populations caused by cross-reactivity with a <i>KRAS</i> mutant DNA species not present in the multiplex are indicated by a yellow dashed square.</p

<i>KRAS</i> multiplex digital PCR assays A-C and corresponding duplex assays.

<p>Multiplex A (top left panel) is an assay combination of 900 nM primers and 500 nM G13C probe (red dashed square), 450 nM primers and 250 nM G12C probe (blue dashed square) and 225 nM primers and 125 nM G12V probe (yellow dashed square). Multiplex B (top middle panel) is an assay combination of 675 nM primers and 375 nM G12S probe (red dashed square), 450 nM primers and 250 nM G12D probe (blue dashed square) and 225 nM primers and 125 nM G13D probe (yellow dashed square). Multiplex C (top right panel) is an assay combination of 675 nM primers and 375 nM G12R probe (red dashed square), 450 nM primers and 250 nM G12A probe (blue dashed square) and 900 nM primers and 500 nM Q61H probe (yellow dashed square). Multiplex C has 900 nM primers and 500 nM Q61H wild-type probe in addition to a G12C wild-type assay. All other wild-type droplet populations shown, except in the Q61H duplex assay, are 450 nM primers and 250 nM G12C wild-type probe. All panels in the left and centre columns show a FAM amplitude up to 18000 and an HEX amplitude up to 6000. Panels in the right column have a FAM amplitude up to 18000 and a HEX amplitude up to 11000.</p

Combining RAS(ON) G12C-selective inhibitor with SHP2 inhibition sensitises lung tumours to immune checkpoint blockade.

Mutant selective drugs targeting the inactive, GDP-bound form of KRASG12C have been approved for use in lung cancer, but resistance develops rapidly. Here we use an inhibitor, (RMC-4998) that targets RASG12C in its active, GTP-bound form, to treat KRAS mutant lung cancer in various immune competent mouse models. RAS pathway reactivation after RMC-4998 treatment could be delayed using combined treatment with a SHP2 inhibitor, which not only impacts tumour cell RAS signalling but also remodels the tumour microenvironment to be less immunosuppressive. In an immune inflamed model, RAS and SHP2 inhibitors in combination drive durable responses by suppressing tumour relapse and inducing development of immune memory. In an immune excluded model, combined RAS and SHP2 inhibition sensitises tumours to immune checkpoint blockade, leading to efficient tumour immune rejection. These preclinical results demonstrate the potential of the combination of RAS(ON) G12C-selective inhibitors with SHP2 inhibitors to sensitize tumours to immune checkpoint blockade