In a poster session, BillionToOne’s NorthStar Select, the company’s liquid biopsy test for tumor profiling – has come out favorably in a head-to-head comparison with commercially available assays.

Northstar Select is a comprehensive genomic profiling (CGP) assay that utilizes Quantitative Counting TemplateTM (QCT) technology, along with advancements in chemistry, panel design, and bioinformatics, to achieve significantly enhanced sensitivity. The assay's performance was evaluated in a prospective validation study involving clinical samples from 182 unique patients with stage III or IV solid tumors. This study compared the concordance of Northstar Select with widely used, commercially available 'comparator' liquid biopsy CGP assays. The patient cohort included individuals with over 15 different types of cancer, with the majority having Lung, Breast, Colorectal, or Prostate cancer.

Key Findings:

• Across all analyzed solid tumor types, a significant proportion of cancers are 'low shedders' of cell-free circulating tumor DNA, as evidenced by variant allele fractions (VAFs) of <0.5% on liquid biopsy. Even in the lowest-shedding cancer types, Northstar Select was highly sensitive for clinically actionable variants.

• In a head-to-head clinical validation, Northstar Select demonstrated higher sensitivity than on-market liquid biopsies, due in large part to the detection of more variants at <0.5% VAF, resulting in a ~2x reduced null report rate.

• The majority of additional SNVs, Indels, and CNVs detected by Northstar Select were clinically actionable, with an equivalent CHIP variant detection rate and improved detection of variants with FDA-approved therapies across >15 genes.

In January 2023, BillionToOne announced the launch of its Northstar liquid biopsy assays for commercial use. The Northstar liquid biopsy assays were made available for patients with late-stage (III/IV) solid tumors. 

In April 2024, BillionToOne announced a partnership with Culmination Bio to validate two of its oncology diagnostic tests: Northstar Select and Northstar Response. Culmination Bio and BillionToOne are working together to leverage their respective strengths to facilitate the development and validation of robust and impactful oncology diagnostics. This collaboration comprises two separate projects, each highly valuable to advancing the development of these diagnostics and making it possible for future regulatory submissions. The first project of 100 patients, launched in early fall, has already seen significant progress, with 60 patient samples collected, many that involve rare mutations, to date. This rapid accumulation of patient data highlights the effectiveness of the partnership in expediting research efforts.

Conclusion

Northstar Select provided clinically relevant insights into the tumors of the majority of patients. When the ctDNA signal was strong, Northstar Select demonstrated a high level of agreement with comparator tests. Additionally, Northstar Select identified additional pathogenic mutations with low variant allele frequency, leading to a greater diagnostic yield compared to other CGP assays. Importantly, these additional findings were not attributed to clonal hematopoiesis of indeterminate potential, indicating that some patients with low ctDNA levels could benefit from the high sensitivity of Northstar Select.