Our Focus

Understanding Genetic Testing

Understanding Genetic Testing

Cancer is a disease of the genome. Genetic testing provides valuable insights that determine if patients can benefit from targeted treatment based on the genomic makeup of their tumors.

In a broad sense, there are two types of genetic tests for cancer:

Singleplex Test

Singleplex tests examine one potential genetic alteration at a time.

Multiplex Test

Multiplex tests utilize a single process to simultaneously examine numerous potential genetic alterations, thereby providing a larger genetic profile of the cancer in one test.

Multiplex tests can be clinically valuable as they allow clinicians to obtain comprehensive information on a large number of genes from the scarce sample of tumor tissue. In recent years, multiplex genetic testing has become increasingly popular in cancer treatment as it provides the most comprehensive understanding the unique genetic alterations of each individual tumor. By knowing the underlying genetics of each cancer patient, doctors can quickly move patients to the right therapies, identify new molecular targets worthy of novel drugs, and test novel drugs in the right study subjects.

In order to identify and enroll the patients most appropriate for our investigational therapies, we are working with clinical, laboratory and molecular pathology partners who integrate multiplex genetic testing into their routine clinical practice. We are also partnering with leading diagnostic companies to develop and commercialize companion diagnostic tests for our programs. Through a collaboration with Illumina, Inc. we are developing a next-generation sequencing (NGS) based companion diagnostic (CDx) for larotrectinib, which targets NTRK gene fusions, and LOXO-292, which targets RET gene alterations, across tumor types. We are working with Ventana Medical Systems, Inc. to develop a pan-TRK immunohistochemistry (IHC) test to identify patients across tumor types suitable for treatment with larotrectinib.

Flashlight vs. Streetlight

Imagine walking down the street holding a flashlight—you can spot the sidewalk just ahead, but all of the details in the surrounding neighborhood are concealed. This is the testing paradigm the field has used for years. A multiplex assay provides the streetlights, which allow us to notice striking things about the neighborhood around us, particularly those things we might never have thought to look for.