Seraseq® ctDNA ESR1 Mix WT

The ESR1 gene is frequently mutated in metastatic breast cancer (MBC), with 15-50% of all metastatic breast cancer patients harboring ESR1 mutations. ESR1 mutations develop in response to selection pressure during treatment and are typically undetectable in the primary tumor. The recent emergence and approval of drug therapy specific to ESR1 mutations in metastatic breast cancer have led to the updated guidance to monitor MBC patients for mutations in both ESR1 and PIK3CA to guide treatment decisions. Such mutations are often polyclonal and co-occurring, and most easily tracked in circulating tumor DNA (ctDNA) in liquid biopsy samples.

Seraseq ctDNA ESR1 reference materials can help confirm the presence of clinically relevant ESR1 and PIK3CA variants including ones in the druggable ligand binding domain of ESR1. Care has been taken in the design of this reference material to include all DNA alterations which lead to the relevant changes to the amino acid sequence of the ESR1 protein to confirm detection of different variant types.

• 22 clinically relevant mutations in ESR1 and PIK3CA

• All variants present at 1% variant allele frequency (VAF) with WT sample available to dilute and challenge limit of detection

• All DNA mutations leading to clinically relevant amino acid substitutions in the ligand binding domain of ESR1 (e.g. 3 different DNA sequences leading to a Y537S amino acid substitution) are present