Camizestrant Shows Improved Survival Benefit Compared to Fulvestrant in Advanced ER-Positive Breast Cancer

Camizestrant (AstraZeneca) met the primary endpoint of a statistically significant and clinically meaningful progression-free survival (PFS) benefit at both 75 mg and 150 mg dose levels compared with fulvestrant 500 mg in post-menopausal patients with estrogen receptor (ER)-positive locally advanced or metastatic breast cancer who were previously treated with endocrine therapy for advanced disease.

Positive high-level results from the SERENA-2 phase 2 trial also showed that the next-generation oral selective estrogen receptor degrader (SERD) was well-tolerated, and its safety profile was consistent with what was observed in previous trials with no new safety signals identified.

Camizestrant is a next-generation oral SERD and pure Erα antagonist that has demonstrated anti-cancer activity across a range of preclinical models, including in patients with ER-activating mutations.

Although endocrine therapies are a well-known treatment for hormone receptor-positive breast cancer, many patients with advanced disease develop resistance to first-line CDK4/6 inhibitors and estrogen receptor (ER)-targeting therapies. The need for research into endocrine therapy research, specifically overcoming resistance for patients with ER-driven disease at all stages of treatment, has led to this being an active areas of focus.

SERENA-2 is a randomized, open-label phase 2 trial evaluating camizestrant at several dose levels compared to fulvestrant in advanced ER-positive, HER2-negative breast cancer. The primary endpoints are defined by response evaluation criteria in solid tumors version 1.1 for 75 mg camizestrant versus fulvestrant (500 mg) and for 150 mg camizestrant versus fulvestrant.

In total, 240 patients were randomized to receive camizestrant or fulvestrant until disease progression. Secondary endpoints include safety, objective response rate, and clinical benefit rate at 24 weeks.

“The results from SERENA-2 show that camizestrant provides a significant improvement in progression-free survival compared to fulvestrant, which has been used to treat patients with HR-positive breast cancer for almost twenty years. These results are meaningful, highlighting the potential of this next-generation oral SERD and supporting the ongoing research program,” said lead study investigator Mafalda Oliveria, MD, PhD, in a press release.

REFERENCE

Camizestrant significantly improved progression-free survival vs. Faslodex in SERENA-2 Phase II trial in advanced ER-positive breast cancer. AstraZeneca. October 26, 2022. Accessed October 26, 2022. https://www.astrazeneca.com/media-centre/press-releases/2022/camizestrant-significantly-improved-progression-free-survival.html