Roche has teamed up with Loxo Oncology to develop a pan-tropomyosin receptor kinase (TRK) immunohistochemistry (IHC) test. The plan is to use the test to assess which patients are more likely to respond to larotrectinib, a TRK inhibitor Loxo is developing as a treatment for a range of solid tumors that share certain genetic characteristics.
Loxo began the process of developing the companion diagnostic for larotrectinib by assessing the feasibility of an IHC pan-TRK assay and piloting the resulting investigational assay. That gave the Stamford, CT-based cancer specialist the confidence to push ahead with development of the assay, and the data to land a partner for the project.
Now, Loxo is looking to Ventana Medical Systems—which was bought by Roche for $3.4 billion in 2008—for help turning its work to date into an optimized and validated diagnostic. Roche will use its OptiView DAB detection technology to support this process and deliver a diagnostic that meets Loxo’s clinical and regulatory needs.
The first goal is to commercialize an analytical assay globally, after which the partners plan to make a Class III assay for pre-market approval (PMA) by FDA. Roche will handle the development and regulatory approval of the companion diagnostic in the U.S. and certain countries in the European Union. In doing so, Roche will draw on analyses of samples taken from patients in clinical trials of Loxo’s larotrectinib to back up claims relating to the use of the test in conjunction with the drug.
In Roche, the thousands of Ventana BenchMark cancer diagnostic instruments the company has installed and IHC, Loxo thinks it has a combination that can gain traction and support the possible commercialization of larotrectinib.
“IHC remains a mainstay of the cancer pathology workup, due in part to its speed, limited tissue requirements, low cost and established reimbursement paradigms,” Loxo CEO Josh Bilenker, M.D. said in a statement. “Diagnostics are a crucial part of our commercial strategy, and we believe IHC will be an important tool, alongside next-generation sequencing, that pathologists can employ in screening for patients who may benefit from larotrectinib.”
The deal further burnishes Ventana’s reputation as a preferred choice for companies seeking to develop companion diagnostics. In recent years Ventana has struck deals with companies including Astellas Pharma, Bayer and Halozyme Therapeutics. Ventana has also worked with its parent company, notably on a PD-L1 assay to partner Tecentriq.