US-based DNA sequencing company Illumina and genetic testing company Myriad Genetics have extended their partnership to improve the access to homologous recombination deficiency (HRD) testing in the US.

HRD is a genomic signature that indicates ineffective repair of double-stranded DNA damage, and HRD status is an important biomarker in tumours involving DNA damage.

Under their initial partnership, Myriad and Illumina jointly developed HRD and TSO 500 tests, which were commercialised worldwide, excluding the US and Japan.

The expanded partnership enables Illumina to offer its research-use-only test TruSight Oncology 500 HRD (TSO 500 HRD) in the US.

It also includes a unique companion diagnostic (CDx) alliance, which facilitates more clinical research for developing gene-based, targeted therapies.

Illumina vice president and oncology business unit general manager Kevin Keegan said: “Research continues to reveal the growing relevance of HRD status across multiple cancers.

“Now with this test, we are empowering labs in the US to unlock the most comprehensive tumour analysis from a single sample.

“This CDx alliance aims to further enable clinical research for HRD testing and therapeutics, globally. Which could lead to greater access to clinical trials for precision, gene-based therapies.”

The TSO 500 HRD research test is said to complement Myriad’s MyChoice CDx HRD technology and Illumina’s pan-cancer test, TSO 500.

Jointly developed with Merck (MSD) and Myriad Genetics, the test identifies the genetic mutations used to evaluate HRD.

It offers a single, complete pan-cancer test to identify important genetic variants and homologous recombination deficiency for understanding the status of cancer.

Under the strategic alliance, Illumina and Myriad will jointly enter into HRD companion diagnostics partnerships with pharmaceutical companies worldwide, excluding Japan.

The joint HRD CDx alliance will aim to pursue HRD regulatory approvals for both the MyChoice HRD Assay companion diagnostic and a future test based on TSO 500 HRD.

Myriad Genetics oncology general manager Michael Lyons said: “Our partnership with Illumina brings together best-in-class HRD technology and next-generation sequencing to create a comprehensive testing solution that supports the advancement of clinical research which should ultimately lead to an improvement for patients.

“The availability of TSO 500 HRD in the US furthers our ability to partner with leading pharmaceutical companies and academic institutions, broadens access to clinical trials, and accelerates the pace of research and scientific innovation.”