Citi has flagged AstraZeneca PLC's (LSE:AZN, NASDAQ:AZN) accelerated approval for Etcamah, known chemically as camizestrant, as a meaningful sentiment driver for the shares.
The oral selective oestrogen receptor degrader has been cleared by the US Food and Drug Administration in combination with a CDK4/6 inhibitor for hormone receptor positive, HER2 negative metastatic breast cancer.
The approval applies once an ESR1 mutation is detected during treatment with an aromatase inhibitor and CDK4/6 inhibitor.
It follows a delayed decision date and a negative advisory committee vote of six to three in April, as well as European approval in July.
Citi notes the label is broadly in line with expectations, covering use alongside all three major CDK4/6 inhibitors: abemaciclib, palbociclib and ribociclib.
Patients must be tested using Guardant360 CDx, an FDA-authorised diagnostic approved simultaneously.
As anticipated following the advisory committee hearing, the label carries a boxed warning over QT prolongation and arrhythmia risk, particularly when combined with ribociclib, alongside monitoring requirements.
Citi models the underlying SERENA-6 opportunity at $450 million, risk-adjusted down to $112 million.
That is dwarfed by the potential $6 billion opportunity from SERENA-4, a trial due in the second half of the financial year that could expand Etcamah into the broader first-line HR positive, HER2-negative population.
Citi adds that should SERENA-4 fail, it still sees a $1.5 billion opportunity underpinned by SERENA-6 alone.
