Spectrum Pharmaceutecals Inc (SPPI)

[antihama]

DS-8201a is not a competitor to Pozi exon20 as it now stands. The bulk of DS-8201a research, from looking at clintrials and World Lung is, as you mention, for over expressing Her2 i.e. the gene/protein that produce too much HER2 NOT a HER2 mutation such Exon 20. At WL, they have an abstract detailing a newer study they are running that has a 40 patient cohort looking at over- expressing HER2 gene (that produces extra HER2 protein) and a second 40 pt cohort that is looking at mutated HER2

Experimental: Cohort 1: HER2 OE
Cohort 1 will enroll approximately 40 subjects with HER2-over-expressing (OE)(immunohistochemistry [IHC] 3+ or IHC 2+), unresectable and/or metastatic NSCLC adenocarcinoma to receive trastuzumab deruxtecan (DS-8201a).

Experimental: Cohort 2: HER2 Mutated
Cohort 2 will enroll approximately 40 subjects with HER2-mutated, unresectable and/or metastatic NSCLC to receive trastuzumab deruxtecan (DS-8201a).

We know from a WL abstract that this second cohort of mutated HER2 will include some exon 20

This multicenter, open-label, 2-cohort, phase 2 study will assess the efficacy and safety of DS-8201a in subjects with HER2-overexpressing or -mutated unresectable and/or metastatic nonsquamous NSCLC that is relapsed/refractory to standard treatment or for which no standard treatment is available (NCT03505710). Overall, approximately 80 subjects will be enrolled; 40 subjects in each of 2 cohorts (cohort 1: HER2-overexpressing [IHC 3+ or IHC 2+]; cohort 2: HER2-mutated including exon 20 insertions and single-nucleotide variants in kinase, transmembrane, and extracellular domains [eg, L755S, V659E, S310F]).

So this study started recruiting 6 months ago and is looking at a small # of exon 20 patients. IF they find evidence it works in this small group of exon 20 pts, they will need to run a larger trial to show effectiveness. IF it works it will be another 2 or 3 yrs out before we can think of it as a competitor to pozi. IMHO.