Eyeing Recent FDA Decision, Promega to Seek Approvals for MSI Assay

Xconomy Wisconsin — 

Laboratory supplies company Promega wants its tests to join the decision-making tools that clinicians use when treating patients and the Fitchburg, WI company now plans to seek the necessary approvals for use of one its tests in colorectal cancer.

Promega aims to secure FDA approval for its microsatellite instability (MSI) assay. The company will also seek a CE Mark, which would allow the company to sell the test in Europe.

The Promega test has been in use since 2004, according to the company. However, up to this point the assay has only been used as a lab-developed test. Under an FDA regulatory exemption, a company that develops and uses assays in-house may do so without needing FDA approval. Lab-developed tests bypass the usual FDA approval process, although the agency has proposed strengthening its oversight.

In a news release, Promega said its MSI assay “is considered the gold standard molecular assay for detecting DNA mismatch-repair deficiency.” Patients with that condition—sometimes abbreviated as dMMR—cannot recognize and correct errors that occur when cells replicate DNA. Without that ability, the patient’s cells continue to replicate these DNA errors.

The failure to repair replication-related errors due to dMMR allows genetic mutations to persist, “especially in regions of repetitive DNA known as microsatellites, giving rise to the phenomenon of MSI,” according to the abstract of a 2010 article published in the journal Histopathology. A high frequency of MSI is a key indicator of Lynch syndrome, a type of hereditary colorectal cancer, according to the abstract.

Promega’s strategy shift to clinical applications follows a recent FDA drug approval decision based in part on the use of genetic tests. In May, the FDA announced an accelerated approval of a drug developed by Kenilworth, NJ-based Merck (NYSE: MRK) for patients whose solid tumors have the dMMR abnormality or a high frequency of MSI. The expanded approval of the drug, pembrolizumab (Keytruda), marked the first time the FDA approved a drug based on treating genetic abnormalities in cancers found in different parts of the body, rather than in the organ where the cancer originated.

The FDA said at the time that about 5 percent of patients with metastatic colorectal cancer had tumors with dMMR or a high frequency of MSI. In treating colorectal cancer, clinicians will need tests to determine if a patient’s tumors have the genetic abnormality likely to respond to a particular treatment, such as pembrolizumab. Promega wants its MSI assay to be that test.

Promega has not previously sought to have the FDA approve any of its products. The company is known for manufacturing and selling life sciences research tools, such as reagents and DNA analysis kits.

“Following recent specific discussions with a number of labs, it is clear that they view the Promega MSI assay as an important tool for determining DNA mismatch-repair deficiency that is a more straightforward measurement relative to next-generation sequencing,” said Heather Tomlinson, who leads the company’s molecular diagnostics business unit, in a prepared statement.

Promega said it will consider additional applications beyond colorectal cancer for its MSI assay. The company said it’s currently “expanding its network of clinical researchers” to become more familiar with other potential applications for its MSI assay technology.