Gilead Sciences now has more clinical data showing that breast cancer drug Trodelvy has helped patients live longer. The FDA already has that data, too, as the drugmaker said Monday that it has submitted application aimed at expanding the approval of the targeted drug to cover a much wider group of breast cancer patients. But details about the data will have to wait. Gilead said these details will be presented at a future medical conference.
The following are the scarce details available about the drug Trodelvy disappointing results presented in June at the American Society of Clinical Oncology (ASCO) annual meeting. Gilead said at the conference that its drug led to a 34 percent improvement in progression-free survival — how long a patient lives without the cancer getting worse — which is the main goal of the Phase 3 trial.
The disappointment was in the overall survival report, a measure of how long patients live after treatment. Regarding this secondary objective of the clinical trial, Gilead said at ASCO that patients treated with its drug lived an average of 5.5 months — just six weeks longer than those treated with chemotherapy. Speaking at ASCO, Véronique Dieras, an oncologist at the Center Eugene Marquis in Rennes, France, acknowledged that this result in overall survival was statistically significant, but said it was unclear whether the result of extending survival by an additional six weeks on average was clinically meaningful .
Foster City, Calif.-based Gilead said Monday that the overall survival results were both statistically significant and clinically relevant. The company offered no further explanation for those results, but said the drug’s safety profile was consistent with earlier studies.
Trodelvy is an antibody drug conjugate that delivers its cancer cell-killing payload to tumors by targeting TROP 2, a protein found on the surface of many types of solid tumors, including most types of breast cancer. The FDA approved Trodelvy in 2020 for the treatment of triple-negative breast cancer, a rare and aggressive type of breast cancer. Gilead is working to expand the drug’s approval for HR positive/HER2 negative breast cancer, which is the most common type of breast cancer. Approval in this indication is important to achieve the hit expectations placed on Trodelvy when Gilead paid $21 billion to acquire Imunomedicsthe biotech company that originally developed the therapy.
Gilead reported $380 million in sales of Trodelvy in 2021. In the first half of this year, the company’s financial reports show that the drug generated $305 million in revenue, an 89.4% increase compared to the same period in 2021.
Gilead has Trodelvy in a phase 3 study evaluating the drug in patients with advanced HR2 positive/HER2 negative breast cancer whose disease has already received extensive prior treatment, including hormone therapy, drugs that block the CDK4/6 enzymes that drive cancer growth , and two to four lines of chemotherapy.
Merdad Parsi, Gilead’s chief medical officer, said in a prepared statement that Trodelvy’s recent results “are important to the breast cancer community, and we are encouraged by the potential this may have to help patients who otherwise have limited alternatives . We look forward to discussing these results with global health authorities, as patients with previously treated HR positive/HER2 negative metastatic disease currently have limited treatment options and poor quality of life.
Gilead is showing how much it believes in Trodelvy’s potential by acquiring the rights to the drug in China and other Asian markets. Everest Medicines acquired those rights in a 2019 deal with Immunomedics. Late Monday, Gilead announced that it did paying Everest $280 million advance for the rights to the drug in these Asian markets. Everest may receive up to $175 million more in milestone payments related to the achievement of regulatory and commercial milestones. Trodelvy is approved in China and Singapore for the treatment of triple-negative breast cancer. It is under review for this indication in other Asian markets.
Public domain image by Stuart S. Martin via National Cancer Institute