FDA Approves FoundationOne CDx for Selpercatinib in RET+ Solid Tumors

The FDA has granted approval to the FoundationOne CDx assay as a companion diagnostic to identify patients with locally advanced or metastatic RET fusion–positive solid tumors previously treated with systemic therapies who may be eligible to receive treatment with selpercatinib (Retevmo), according to a press release from Foundation Medicine Inc.¹

“With a growing need for solutions for patients with rare fusions, high-quality companion diagnostics provide critical information to support oncologists in the development of personalized treatment plans,” Mia Levy, MD, PhD, chief medical officer at Foundation Medicine, said in the press release.¹ “With our experience successfully navigating the complexities of a pan-tumor approval, we’re proud to have another companion diagnostic for our FDA-approved tissue test that can help enable broader access to an important therapy option for RET-fusion positive solid tumors.”

The FDA previously approved selpercatinib in RET fusion–positive solid tumors that have progressed following prior systemic therapy in September 2022.² Supporting data for the approval in this indication came from the phase 1/2 LIBRETTO-001 trial (NCT03157128), in which selpercatinib yielded an overall response rate (ORR) of 44% (95% CI, 28%-60%) among 41 patients with RET fusion–positive solid tumors. Additionally, investigators reported ORRs of 55.0% (95% CI, 23.0%-83.0%) in 11 patients with pancreatic adenocarcinoma, 20.0% (95% CI, 2.5%-56.0%) in 10 with colorectal cancer, 50.0% (95% CI, 7.0%-93.0%) in 4 with salivary gland cancer, and 33.0% (95% CI, 0.8%-91.0%) in 3 with unknown primary disease.

“In the LIBRETTO-001 trial, selpercatinib demonstrated clinically meaningful and durable responses across a variety of tumor types in patients with RET-driven cancers, including pancreatic, colon, and other cancers in need of new treatment options,” study co-investigator Vivek Subbiah, MD, associate professor of Investigational Cancer Therapeutics at the University of Texas MD Anderson Cancer Center, said in a press release at the time of the approval.² “These data and FDA approval of the tumor-agnostic indication underscore the importance of routine, comprehensive genomic testing for patients across a wide variety of tumor types.”

Developers designed the FoundationOne CDx to analyze more than 300 cancer-related genes for alterations in a patient’s tumor, which may determine whether selpercatinib is a suitable therapy for those whose tumors harbor RET fusions. According to the press release, the assay is approved as a companion diagnostic across more than 30 indications, which include lung, breast, prostate, and colon cancer.

The FoundationOne CDx assay is intended only for prescription use among qualified health care professionals based on oncology guidelines for patients with solid malignant neoplasms. Additionally, developers caution that a negative test result may not negate the presence of a genomic alteration, and that patients are not guaranteed to be matched to a suitable treatment.

The FDA also approved selpercatinib in RET fusion-positive non–small cell lung cancer (NSCLC) in September 2022.³ The agency’s approval was based on extended follow-up data from the LIBRETTO-001 trial, which included 316 patients with locally advanced or metastatic RET fusion-positive NSCLC. In the NSCLC cohort, selpercatinib produced an ORR of 84% (95% CI, 73%-92%), and a median duration of response of 20.2 months (95% CI, 13-not estimable).

References

1. U.S. Food and Drug Administration (FDA) approves FoundationOne®CDx as a companion diagnostic for Lilly’s Retevmo® (selpercatinib) for certain patients with solid tumors. News release. Foundation Medicine Inc. October 9, 2023. Accessed October 11, 2023. https://bit.ly/3RSQkZE
2. FDA approves Lilly’s Retevmo® (selpercatinib), the first and only RET inhibitor for adults with advanced or metastatic solid tumors with a RET gene fusion, regardless of type. News release. Eli Lilly and Company. September 21, 2022. Accessed October 11, 2023. https://prn.to/3dFC8Bz
3. FDA approves selpercatinib for locally advanced or metastatic RET fusion-positive non-small cell lung cancer. News release. FDA. September 21, 2022. Accessed October 11, 2023. https://bit.ly/3f6PjMm