Dive Brief:

• Exact Sciences, Guardant Health, and Oncocyte were among the companies that shared data on tests to help detect cancer and guide treatment protocol at the American Society of Clinical Oncology (ASCO) virtual meeting, held May 29-31.

• The tests are designed to analyze the genetics of cancer patients and, in doing so, help physicians choose treatment regimens that are most likely to deliver positive outcomes.

• Exact Sciences and Oncocyte are competing for share in the market of tests that guide breast cancer treatment. In a research note on Monday, SVB Leerink​​ analysts said they see continued momentum in cancer diagnostics, with liquid assays "gaining prominence" and Guardant Health's product in that arena "continuing to strengthen its dominance in the market."

Dive Insight:

The flurry of publications at ASCO's Scientific Program are part of a broader fight for market share in an emerging sector of genetic tests to guide cancer diagnosis treatment. Exact Sciences and Guardant Health are two of the biggest players in the space and are gearing up to compete on detecting colorectal cancer.

Exact Sciences on Friday highlighted the results of three studies involving the Oncotype DX Breast Recurrence Score product, a genomic test it gained in its acquisition of Genomic Health last year. The test assesses how likely a cancer is to respond to certain treatments and recur in the future. The largest of the three studies showed Oncotype DX can be used to identify certain breast cancer patients who can receive just neoadjuvant hormonal therapy, a nonstandard treatment, without compromising efficacy. 

Exact Sciences is just one of a clutch of companies to use the ASCO event to share data on breast cancer-related tests.

Oncocyte also presented breast cancer data at the ASCO event. The diagnostics company is best known for its oft-delayed lung cancer diagnostic, but is also applying its approach to triple-negative breast cancer (TNBC).

The study applied a 27-gene algorithm to samples taken from TNBC patients who received AstraZeneca’s PD-1 checkpoint inhibitor Imfinzi. Researchers the Oncocyte test is better at predicting if a patient will respond to Imfinzi than PD-L1 immunohistochemistry staining, a way to assess expression of a ligand involved in the drug’s mechanism of action.

Elsewhere at the ASCO event, researchers from Samsung Medical Center in Seoul, South Korea shared data on the use of Guardant Health’s Guardant360 liquid biopsy in predicting which patients will respond and develop resistance to ALK inhibitors such as Pfizer’s Xalkori and Roche’s Alecensa.

The researchers linked the absence of detectable cell-free plasma DNA at baseline to better outcomes. Conversely, the presence of co-occurring TP53 alterations and ALK fusions at the start of the study was associated with worse outcomes. 

Analysts at SVB Leerink also addressed COVID-19's broader potential impact on the oncology diagnostics market. "Should the outbreak extend beyond current expectations, it would likely be a headwind for oncology diagnostic companies as a result of fewer patient visits and clinical trials," a research note Monday said.