AstraZeneca got a huge regulatory boost after the US Food and Drug Administration (FDA) approved its breast cancer drug camizestrant, sold under the brand name Etcamah.
Doctors now have another oral treatment option for a specific group of patients with advanced or metastatic breast cancer.
The FDA granted accelerated approval for Etcamah in adults with hormone receptor-positive (HR+), HER2-negative locally advanced or metastatic breast cancer with an ESR1 mutation.
The medication is for patients with advanced disease after an aromatase inhibitor and CDK4/6 inhibitor have been administered.
Patients must undergo an FDA-authorized diagnostic test to check whether their cancer has the required ESR1 mutation before starting treatment.
Camizestrant is part of a newer group of medicines called “oral selective estrogen receptor degraders (SERDs)”.
These drugs target estrogen receptors, which are very active in hormone-sensitive breast cancer. The goal is to stop the cancer from taking estrogen-based signals to continue growing.
The FDA decision is significant for AstraZeneca because the drug had been questioned by an advisory panel earlier this year.
In April, the FDA's Oncologic Drugs Advisory Committee voted 6-3 against the treatment strategy because of the strength and clinical relevance of the available evidence.
However, FDA advisory committees are not legally binding. The agency reviewed the available evidence and approved it and then moved forward on the accelerated approval.
The decision was supported by results of the Phase 3 SERENA-6 clinical trial. The study showed that patients who switched to camizestrant after an ESR1 mutation emerged experienced a longer period before their disease developed compared to those who continued to take aromatase inhibitor therapy.
According to the trial results, camizestrant improved progression-free survival by roughly 7.6 months.
The treatment is designed to be used in combination with a CDK4/6 inhibitor, a class of medicines already widely used in the treatment of HR-positive advanced breast cancer.
The strategy is also consistent with the growing utilization of genetic testing to guide cancer care.
Testing for mutations such as ESR1 can help doctors identify when a tumor may be developing resistance to an existing hormone-based treatment.
This can allow treatment decisions to be adjusted according to changes in the cancer.
For AstraZeneca, Etcamah is also another potential growth driver in its growing oncology business.
It has previously predicted that camizestrant could eventually generate sales of over $5 billion a year, and hence camizestrant's commercial performance will be dependent on patient uptake, competition and additional clinical evidence.
The FDA’s accelerated approval program is designed to make promising treatments for serious diseases available sooner when early evidence suggests their benefits.
Adopting any of these drugs can require additional studies to ensure the drug’s effectiveness.
Now that Etcamah is approved in the US, AstraZeneca will focus on bringing the medicine to eligible patients and will further assess the long-term benefits and potential in breast cancer treatment.
