AZ grabs pair of EU approvals for top cancer drugs

AstraZeneca is celebrating two new approvals for cancer therapies Imfinzi and Enhertu in the EU as it faces the threat of increased competition to its top seller Tagrisso.

Daiichi Sankyo-partnered anti-HER2 drug Enhertu (trastuzumab deruxtecan) has been cleared by the European Commission for use in advanced breast cancer cases with lower levels of the HER2 biomarker while AZ's PD-1 inhibitor Imfinzi (durvalumab) has claimed approval for use before and after surgery for early-stage non-small cell lung cancer (NSCLC).

The two approvals – both of which have already been granted in the US – come as AZ's $6.6 billion EGFR inhibitor Tagrisso (osimertinib) is facing a tougher challenge from Johnson & Johnson's rival Rybrevant (amivantamab) and Lazcluse (lazertinib) combination, which improved survival in a head-to-head trial.

The Enhertu approval applies to the use of the drug in advanced breast cancers that are HR-positive and either HER2-low or HER2-ultra-low who have previously been treated with one or more lines of endocrine therapy – but are not suitable for another endocrine round.

It makes Enhertu the first approved option for the HER2-ultralow category, which unlocks a sizeable new patient population and moves the drug up the treatment pathway ahead of chemotherapy. Daiichi Sankyo and AZ have estimated that approximately 60% to 65% of HR-positive, HER2-negative breast cancers are HER2-low and potentially an additional 25% may be HER2-ultra-low.

The approval is based on the results of the DESTINY-Breast06 trial, one of the highlights of last year's ASCO congress, which showed a response rate of over 60% with Enhertu and a 38% improvement in progression-free survival (PFS) compared to chemo.

Enhertu is already a blockbuster, with worldwide sales of more than $3.75 billion last year, up from $2.57 billion in 2023, and the new approval has the potential to unlock further growth.

The Imfinzi approval covers the use of the drug in combination with chemo pre-surgery and on its own after surgery in NSCLC patients with a high risk of recurrence whose tumours don't express EGFR and ALK mutations that would make them suitable for targeted therapies.

It makes the drug an alternative to MSD's PD-1 inhibitor Keytruda (pembrolizumab), which was approved for this perioperative use in early-stage NSCLC, and could lend additional momentum to Imfinzi, which grew 21% to $4.7 billion last year.

In the AEGEAN trial, the Enhertu regimen achieved a 32% reduction in the risk of cancer recurrence, progression, or death compared to chemo given alone pre-surgery followed by placebo.

Around 25%-30% of all patients with NSCLC are diagnosed early enough to have surgery to try to cure the cancer but, in most cases, the disease recurs and the five-year survival rate for people with stage II disease is 36% to 46%, according to AZ.