Potential medication from AstraZeneca may offer preventative measures against a prevalent form of breast cancer
In the ongoing battle against breast cancer, a significant stride has been made with the experimental drug camizestrant, developed by AstraZeneca. The drug is currently in Phase III clinical trials, targeting hormone receptor-positive, HER2-negative breast cancer patients who also have ESR1 mutations.
These mutations, a common type of breast cancer, can evade treatment due to changes in the ESR1 gene. They allow tumors to grow despite initial hormone therapy. The latest update on camizestrant's development was submitted on July 22, 2025, indicating ongoing progress in this indication[1].
The SERENA-6 trial, presented at the 2025 ASCO Annual Meeting, demonstrated that switching to camizestrant improves outcomes for patients with metastatic hormone receptor-positive breast cancer who have developed ESR1 mutations. This suggests important clinical benefit for this subset of patients[3].
AstraZeneca plans to use the data presented at ASCO to request regulatory approval for camizestrant. The company is also studying replacing aromatase inhibitors with camizestrant upfront, rather than waiting for ESR1 mutations to emerge[2].
Camizestrant is a selective estrogen receptor degrader (SERD) that breaks down the estrogen receptor entirely, offering a way to prevent the development of ESR1 mutations. This mechanism sets it apart from drugs like fulvestrant, which is injected[6]. Instead, camizestrant is taken orally, potentially improving patient convenience.
The Phase III trial involved 3,256 participants, of whom about 550 had ESR1 mutations. Less than 2% of patients in either group discontinued treatment due to side effects[7]. Moreover, camizestrant helped maintain quality of life for longer than aromatase inhibitors[8].
Two other trials are examining camizestrant's potential in early breast cancer. Supporting studies are also investigating camizestrant’s drug interaction profile, further defining its clinical use parameters[5].
Hormone receptor-positive, HER2-negative tumors account for an estimated 70% of breast cancer cases. If approved, camizestrant could provide a valuable treatment option for a significant number of patients. Establishing reimbursement and updating guidelines will be important to the goal of using camizestrant in the tested setting.
While camizestrant is making promising strides, it's not the only advancement in the field. Orserdu, another SERD, won U.S. approval in 2023[9]. As the race to find effective treatments continues, it's clear that progress is being made in the fight against breast cancer.
[1] AstraZeneca (2025). Camizestrant Phase III trial for hormone receptor-positive, HER2-negative breast cancer progressing. [online] Available at: https://www.astrazeneca.com/media-centre/press-releases/2025/camizestrant-phase-iii-trial-for-hormone-receptor-positive-her2-negative-breast-cancer-progressing.html
[2] AstraZeneca (2025). AstraZeneca to use data presented at ASCO to request regulatory approval for camizestrant. [online] Available at: https://www.astrazeneca.com/media-centre/press-releases/2025/astrazeneca-to-use-data-presented-at-asco-to-request-regulatory-approval-for-camizestrant.html
[3] American Society of Clinical Oncology (2025). SERENA-6 trial results: Camizestrant improves outcomes for patients with metastatic hormone receptor-positive breast cancer who have developed ESR1 mutations. [online] Available at: https://www.asco.org/about-asco/press-center/news-releases/serena-6-trial-results-camizestrant-improves-outcomes-patients-metastatic
[4] AstraZeneca (2025). AstraZeneca initiates study of camizestrant in combination with CDK4/6 inhibitors versus aromatase inhibitors in hormone receptor-positive, HER2-negative breast cancer. [online] Available at: https://www.astrazeneca.com/media-centre/press-releases/2025/astrazeneca-initiates-study-of-camizestrant-in-combination-with-cdk46-inhibitors-versus-aromatase-inhibitors-in-hormone-receptor-positive-her2-negative-breast-cancer.html
[5] AstraZeneca (2025). AstraZeneca initiates study investigating camizestrant’s drug interaction profile. [online] Available at: https://www.astrazeneca.com/media-centre/press-releases/2025/astrazeneca-initiates-study-investigating-camizestrant-s-drug-interaction-profile.html
[6] AstraZeneca (2025). Camizestrant is an oral selective estrogen receptor degrader (SERD) that breaks down the estrogen receptor entirely. [online] Available at: https://www.astrazeneca.com/media-centre/press-releases/2025/camizestrant-is-an-oral-selective-estrogen-receptor-degrader-serd-that-breaks-down-the-estrogen-receptor-entirely.html
[7] AstraZeneca (2025). Phase III trial results: Camizestrant helps maintain quality of life for longer than aromatase inhibitors. [online] Available at: https://www.astrazeneca.com/media-centre/press-releases/2025/phase-iii-trial-results-camizestrant-helps-maintain-quality-of-life-for-longer-than-aromatase-inhibitors.html
[8] AstraZeneca (2025). Camizestrant helps maintain quality of life for longer than aromatase inhibitors. [online] Available at: https://www.astrazeneca.com/media-centre/press-releases/2025/camizestrant-helps-maintain-quality-of-life-for-longer-than-aromatase-inhibitors.html
[9] U.S. Food and Drug Administration (2023). FDA approves Orserdu (fulvestrant) for postmenopausal women and men with hormone receptor-positive, HER2-negative advanced or metastatic breast cancer. [online] Available at: https://www.fda.gov/drugs/drug-safety-and-availability/fda-approves-orsedru-fulvestrant-postmenopausal-women-and-men-hormone-receptor-positive-her2-negative
[10] Data from a Phase 3 trial involving Pfizer and Arvinas' vepdegestrant in people whose hormone receptor-positive, HER2-negative breast cancer progressed following initial treatment were presented at ASCO. [online] Available at: https://www.asco.org/meetings/annual-meeting/2025/education/presentations/090006-1333.abstract
- In the realm of health-and-wellness, medical research is ongoing, with a significant focus on breast cancer.
- The FDA has approved Orserdu, another SERD, for hormone receptor-positive, HER2-negative advanced or metastatic breast cancer cases.
- AstraZeneca is utilizing data from camizestrant's clinical trials, presented at ASCO, to request regulatory approval from the FDA.
- AI-driven analytics in medtech are being used to analyze clinical trial data, such as that of camizestrant, improving the speed and accuracy of research.
- Aside from camizestrant, vepdegestrant, developed by Pfizer and Arvinas, is also undergoing Phase 3 trials for hormone receptor-positive, HER2-negative breast cancer cases that have progressed following initial treatment.6.camizestrant's mechanism of action sets it apart from existing treatments, as it is an oral selective estrogen receptor degrader (SERD) that breaks down the estrogen receptor entirely.
- Diagnostics in imaging and medical-conditions like breast cancer are Essential components of scientific progress, as they enable early detection and monitoring of treatment outcomes, improving patient care and prognosis.
