The FDA has signed off on label expansions for two of the world’s most important cancer medicines—Merck’s Keytruda and Pfizer and Astellas’ Xtandi.
Keytruda’s expansion is in stomach cancer, allowing its use alongside chemotherapy to treat first-line patients with locally advanced unresectable or metastatic HER2-negative gastric or gastroesophageal junction (GEJ) adenocarcinoma.
Xtandi’s new indication expands its already deep portfolio in the treatment of prostate cancer. It now becomes the only androgen receptor inhibitor approved by the FDA for patients with nonmetastatic castration-sensitive prostate cancer (nmCSPC) with biochemical recurrence at high risk for metastasis (high-risk BCR). These patients can be treated with Xtandi with or without GnRH analog therapy.
Of men who have had prostate cancer treatment, 20% to 40% will have BCR within 10 years. Of those with high-risk BCR, 90% will develop metastatic disease, with one in three dying.
The nod was backed up by the phase 3 EMBARK trial which showed that Xtandi plus hormone reducer leuprolide produced a significant reduction in the risk of metastasis or death over placebo and leuprolide. As a secondary measure, Xandi as a solo agent, also achieved a statistically significant reduction in the risk of metastasis or death versus placebo and leuprolide.
In his 40 years of treating prostate cancer patients, Neal Shore M.D., the primary investigator of the trial, said that there hadn’t been any progress in the care of patients with BCR until the completion of the EMBARK study.
The approval represents an important advancement, and Xtandi could be a new standard-of-care option, Shore said in a release.
The nod comes after the FDA expedited Pfizer and Astellas’ application with priority review, fast-track and real-time oncology designations. Xtandi is the only novel hormone therapy approved for three types of prostate cancer. Sales of Xtandi reached $5.9 billion in 2022, which was a 27% increase from the previous year.
As for Keytruda, the blessing is its seventh indication in gastrointestinal cancers in the United States and the 38th overall for the checkpoint inhibitor which is poised this year to overtake AbbVie’s Humira as the world’s top-selling drug. Merck reported sales of $20.9 billion last year for Keytruda, which was a 22% increase from 2021.
The approval was based on data from the phase 3 KEYNOTE-859 trial, which showed Keytruda plus chemotherapy reduced the risk of death by 22% compared to chemotherapy alone. Median overall survival was 12.9 months for patients on the combo versus 11.5 months for those on chemotherapy.
The new go-ahead is once again putting additional pressure on Keytruda’s rival, Bristol Myers Squibb’s Opdivo, which in 2021 got immunotherapy's first nod in stomach cancer.
Earlier this week, Agilent Technologies secured an FDA green light for its diagnostic assay which can identify gastric and gastroesophageal junction adenocarcinoma patients that are suited for Keytruda’s newly approved combo.
Last week, Europe’s Committee for Medicinal Products for Human Use recommended approval of the use of Keytruda along with the antimetabolite gemcitabine and chemotherapy for the first-line treatment of adults with locally advanced unresectable or metastatic biliary tract cancer.