A Roche drug has failed a phase 2 study as part of a new class of breast cancer drugs, marking the latest advance in the emerging field of oral therapy that degrades a key protein that fuels cancer cell growth. The clinical trial results follow disappointing data previously reported by Roche’s main rivals Sanofi and Radius Health.
The Swiss pharma giant released its First Quarter 2022 Financial Results. Overall survival data for patients in the Phase 2 study are not yet available. The results of the study will be presented at a medical meeting later this year, Roche said.
Giredestrant is a selective estrogen receptor degrader (SERD). The estrogen receptor (ER) is a major driver of hormone-positive breast cancer, the most common type of breast cancer. The results, reported Monday, came from a phase 2 study that enrolled about 300 patients with ER-positive, HER2-negative breast cancer whose disease progressed after one or two earlier treatments. The Roche drug was compared with doctors’ choice of AstraZeneca’s drug fulvestrant or aromatase inhibitors, a type of endocrine therapy used to treat breast cancer.
Fulvestrant validated a method for degrading ER as a treatment for breast cancers that are positive for this receptor. While the drug has become a best-seller, it is painful to administer by intramuscular injection. In addition, developers of oral SERDs say their small-molecule drug can achieve better efficacy than fulvestrant. The Oral SERD class is working hard to fulfill this claim.
Disappointing giredestrant results came in mid-March when Sanofi announced its oral SERD, amcenestrant, Failure To meet the primary goal of improving progression-free survival in phase 2 clinical trials. Meanwhile, the oral SERD elacestrant developed by Radius Health and licensed to the Menarini Group, achieved the main goal Its Phase 3 test last fall in breast cancer. However, Radius shares later fell as a closer look at the data revealed that the positive numbers were driven by outcomes from a cohort of patients.
Roche points to a group of patients as a potential way forward for its oral SERD. Despite the Phase 2 failure, the company said the results showed the drug worked better in patients whose cancers were more dependent on estrogen receptor activity. The company is also evaluating the drug as an early treatment for breast cancer patients, a strategy Sanofi said it is also pursuing.
This isn’t the first time Roche has dealt with disappointing oral SERD data. In 2014, the pharmaceutical giant paid $725 million upfront to acquire Serragon Pharmaceuticals. Three years later, Roche discloses that it has discontinued Phase 2 development of Seragon’s lead oral SERD.
The promise of oral SERDs offering better efficacy continues to attract more competitors. last summer, Pfizer commits to $1 billion partnership with Arvinas, a deal based on encouraging early-stage clinical breast cancer data based on a New Haven, Connecticut-based biotech drug that employs a mechanism called targeted protein degradation. Meanwhile, New York-based Zentalis is in mid-stage testing of its oral SERD candidate, a small molecule called ZN-c5.
Photo: Giuseppe Aresu/Bloomberg via Getty Images
