FDA Approves BRACAnalysis CDx Companion Diagnostic Assay for Olaparib in Breast Cancer Treatment

Following the recent approval of olaparib (Lynparza) for certain patients with breast cancer, the FDA has approved the BRACAnalysis CDx assay for use as a companion diagnostic to select patients with germline BRCA-mutated, human epidermal growth factor receptor 2 (HER2)-negative, high-risk early breast cancer who may derive clinical benefit from olaparib.¹

On March 11, the FDA approved olaparib for the adjuvant treatment of patients with germline BRCA-mutated, HER2-negative, high-risk early breast cancer who were previously administered chemotherapy prior to or following surgery.³ The approval was based on findings from the multicenter, randomized, placebo-controlled, phase 3 OlympiA trial, during which olaparib showed a 42% improvement in invasive disease-free survival (iDFS) versus placebo, which was deemed statistically significant and clinically meaningful (HR, 0.58; 95% CI, 0.46-0.74; P <.0001).^2,3

Further, the study showed that adjuvant olaparib produced a 32% reduction in the risk of disease progression or death versus placebo (HR, 0.68; 95% CI, 0.50-0.91; P = .0091). Safety findings from treatment with olaparib were consistent with what was observed in prior studies.

The BRACAnalysis CDx assay is intended for the qualitative detection and classification of variants in the protein-coding regions and intron/exon boundaries of the BRCA1 and BRCA2 genes through the use of genomic DNA extracted from whole blood specimens.² By leveraging polymerase chain reaction and Sanger sequencing, the test can detect single nucleotide variants and small insertions and deletions, according to Myriad Genetics.

“Studies have demonstrated that PARP inhibitors are highly effective in patients with BRCA1/BRCA2 mutations. Once we identify these patients, they will have more options for treatment,” said Thomas Slavin, MD, chief medical officer of Myriad Genetics, in a press release.¹ “This important advancement underscores the need for breast cancer patients being evaluated for approved therapies to know their BRCA status with an FDA-approved test right after diagnosis to help ensure they will receive the best available therapy. Additionally, the quick adoption of OlympiA criteria by guideline committees greatly supports the advancement of genomics in clinical care.”

OlympiA enrolled 1836 patients with HER2-negative breast cancer with a germline BRCA mutation. Patients were randomized 1:1 to receive 300 mg of oral olaparib twice daily for 1 year (n = 921) or placebo (n = 915). Furthermore, patients had to have been treated for stage II or III breast cancer and have completed surgery and chemotherapy, with or without radiotherapy.

Inclusion criteria also required patients to have a high risk of disease recurrence. Patients previously treated with a PARP inhibitor were not eligible for enrollment. The primary end point was iDFS, with secondary end points including distant disease-free survival (DDFS), overall survival (OS), health-related quality of life, and safety.

The study showed that patients administered olaparib had a 43% decrease in DDFS, including metastatic disease, new cancer, and death due to any cause (stratified HR, 0.57; 99.5% CI, 0.39-0.83; P < .0001). The difference in the 3-year DDFS rate between olaparib and placebo was 7.1% (87.5% vs 80.4%, respectively; 95% CI, 3.0%-11.1%).

At the time of the interim analysis, OS data were immature. Although fewer deaths were reported in patients administered olaparib compared with placebo, OS was not significantly different between the 2 study arms (stratified HR, 0.68; 99% CI, 0.44-1.05; P = .024). The difference in the 3-year OS rate between the olaparib and placebo groups was 3.7% (92.0% vs 88.3%, respectively; 95% CI, 0.3%-7.1%).

Olaparib was not found to increase serious adverse effects (AEs), including hospital admissions or occurrences of other cancers, such as leukemia. Grade 3 or higher AEs were reported more frequently in patients administered olaparib, and included anemia (9%), neutropenia (5%), leukopenia (3%), and fatigue (2%).

References

1. Myriad Genetics receives FDA approval of BRACAnalysis CDx as a companion diagnostic for Lynparza in early breast cancer. News release. Myriad Genetics, Inc.; March 11, 2022. Accessed March 14, 2022. https://bit.ly/35ZZbTP
2. BRACAnalysis CDx. Myraid Genetics, Inc. website. Accessed March 14, 2022. https://bit.ly/3w5LRbm
3. Lynparza approved in the US as adjuvant treatment for patients with germline BRCA-mutated HER2-negative high-risk early breast cancer. News release. AstraZeneca; March 11, 2022. Accessed March 14, 2022. https://bit.ly/3tQePcn