The FDA has approved Roche AG’s Ventana MMR Rxdx panel for patients with advanced or recurrent endometrial cancer. The companion diagnostic is the first to identify patients who are eligible for treatment with Glaxosmithkline plc’s (GSK’s) Jemperli (dostarlimab-gxly) monotherapy. The PD-1 antibody immunotherapy received FDA approval on Thursday.

Mismatch repair (MMR) deficiency is most often found in endometrial cancer. The Ventana MMR Rxdx panel is a qualitative immunohistochemistry (IHC) test for assessing several MMR proteins in endometrial cancer tissue using light microscopy.

Endometrial cancer is the fourth most common malignancy in women in North America, and kills an estimated 90,000 women worldwide each year. DNA MMR proteins have been shown to be predictive biomarkers for PD-1 therapy. With few treatment options for patients with recurrent or advanced disease, the Ventana CDx enables doctors to target therapy to patients most likely to respond.

Jemperli is only one of two programmed cell death protein 1 (PD1) drugs indicated for endometrial cancer. It will compete with Merck & Co. Inc.’s Keytruda (pembrolizumab). The medication was approved for use in patients with recurrent or advanced DNA MMR deficient disease whose cancer has progressed on or following previous treatment with a platinum-containing chemotherapy.

‘New therapeutic option’

“We are excited to launch this companion diagnostic test with GSK to help recurrent and advanced endometrial cancer patients with limited options,” said Thomas Schinecker, CEO of Roche Diagnostics. “This test provides clinicians with an effective tool to identify patients best suited for treatment with GSK’s Jemperli, providing a new therapeutic option for women with MMR-deficient endometrial cancer whose disease progresses on or following initial chemotherapy treatment.”

The approval is the latest label update to Roche’s Ventana MMR IHC (immunohistochemistry) panel. Last month, the FDA approved the Ventana ALK (d5F3) companion diagnostic assay for use with Pfizer Inc.’s Lorbrena (lorlatinib), joining prior indications identify ALK-positive non-small-cell lung cancer patients eligible for treatment with Pfizer’s Xalkori (crizotinib), Novartis AG’s Zykadia (certinib) or Genentech Inc.’s Alecensa (alectinib).

The Ventana line also includes a companion diagnostic to detect the HER2 biomarker in breast cancer being treated with Genentech’s Herceptin (trastuzumab) one for the measurement of PD-L1 levels to identify patients for treatment with Tecentriq (atezolizumab) plus Abraxane (nab-paclitaxel), made by Genentech and Celgene Corp., respectively.

Roche acquired Ventana Medical Systems Inc. for $3.4 billion in 2008.

Companion diagnostic for cachexia

In February, the FDA granted breakthrough device designation to Roche’s Elecsys GDF-15 assay as a companion diagnostic to Pfizer’s investigational drug, PF-06946860. The in vitro diagnostic immunoassay is intended to measure growth differentiation factor-15 in adult patients with solid tumors who experience unexpected weight loss, or cachexia, while being treated with the chemotherapy. Pfizer’s drug is currently being evaluated in patients with cachexia and non-small-cell lung cancer, pancreatic cancer or colorectal cancer.

Basel, Switzerland-based Roche reported 55% growth in diagnostics to CHF4.3 billion (US$4.7 billion) for the first quarter of 2021, fueled by tailwinds in COVID-19 test sales. Total revenue declined 1% to CHF14.9 billion, with lower sales of some key drug products pushing pharma revenue down 14% to CHF10.6 billion.

Morningstar analyst Karen Andersen sees the potential for above-market diagnostics growth and competitive advantage over the next 10 years. “Roche’s wide moat arises from its status as the leader in oncology therapeutics and in vitro diagnostics, and the firm has a promising strategy of combining its expertise in both areas to generate a growing personalized medicine pipeline, making use of companion diagnostics,” she wrote in a note, adding that much of the advantage in pharmaceuticals comes from Genentech, which Roche acquired outright in 2009.

“Since then, Roche has established a record of developing and launching personalized medicine therapies and companion diagnostics in oncology, including Tarceva in EGFR-mutant patients, Kadcyla and Perjeta for HER2+ patients, and melanoma drug Zelboraf for BRAF mutation patients,” Andersen continued. This strategy could help Roche justify higher prices for personalized therapies in the face of global price constraint pressures.