It has been a mixed few days for AstraZeneca’s oncology pipeline, as two drugs in its lung cancer portfolio have secured a Phase III success while its breast cancer therapy, Etcamah (camizestrant), missed its primary goal in a late-stage study.
The first win for AstraZeneca stems from the Phase III DESTINY-Lung04 study (NCT05048797), in which the company’s Daiichi Sankyo co-developed antibody drug conjugate (ADC), Enhertu (trastuzumab deruxtecan) demonstrated its potential as the new standard of care (SoC) for frontline, HER2-mutant non-squamous non-small cell lung cancer (NSCLC).
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During the trial, the pair pitted Enhertu against the current SoC of chemotherapy plus MSD’s Keytruda (pembrolizumab). According to results presented at the IASLC’s ongoing 2026 World Conference on Lung Cancer (WCLC), taking place in Seoul, South Korea, Enhertu significantly improved progression-free survival (PFS) over SoC—reducing the risk of disease progression or death by 37%, while extending median PFS by six months over the control treatment to 14.3 months.
Researchers also observed favourable PFS trends across key patient subgroups, including those with cancer that had spread to the brain and liver, as well as those with certain HER2 mutations linked to poor prognosis.
The objective response rate (ORR) in the Enhertu-treated patient group was 70%, versus 44.5% in the SoC arm, while the drug’s safety profile was consistent with prior studies.
This makes Enhertu the first therapy to demonstrate superior PFS benefits to the SoC in HER2-mutant NSCLC, which AstraZeneca’s oncology and haematology EVP Susan Galbraith says could highlight the drug’s potential in newly diagnosed metastatic patients. According to Galbraith, this period is when treatment “has the greatest opportunity to improve outcomes”.
HER2 mutations are fairly uncommon in NSCLC, with researchers observing them in around 2%-4% of cases. However, they are often linked to a poor prognosis, with only around one in ten patients living beyond five years after diagnosis. US regulators have currently approved Enhertu to treat various types of HER2-expressing tumours, such as NSCLC, as well as breast and gastric cancers.
GlobalData, parent company of Clinical Trials Arena, forecasts the drug will pull in sales of just under $13bn in 2032.
Tagrisso touts eight-year OS benefit in EGFR-mutated NSCLC
Also at WCLC, AstraZeneca presented some positive long-term outcome data from a Phase III trial on its EGFR tyrosine kinase inhibitor (TKI), Tagrisso (osimertinib).
The British-Swiss pharma titan shared data from the Phase III ADAURA study (NCT02511106), which was looking at the long-term survival outcomes in patients who received either Tagrisso or placebo after having surgery to remove their EGFR-mutated NSCLC. Several patients in this trial also received chemotherapy, though this was at the discretion of the patient and their physician.
At a follow-up of eight years, researchers revealed that Tagrisso reduced the risk of death by 47% over placebo across all predefined subgroups, highlighting its ability to offer sustained overall survival (OS) benefits to a variety of patients over a long time period.
According to ADAURA principal investigator Roy Herbst, the results from this trial were “particularly impressive” due to high rates of crossover to Tagrisso following disease recurrence.
Herbst said: “This durable OS benefit reinforces the importance of prioritising EGFR testing at diagnosis so as many patients as possible can benefit from this transformative therapy.”
Complementary real-world evidence (RWE) debuted at WCLC 2026 also highlighted the benefits of finishing Tagrisso’s three-year treatment course, as those who discontinued early were more than twice as likely to experience disease recurrence or death.
Depending on location, EGFR mutations in NSCLC vary in prevalence, with around 10%-15% of European and American patients presenting with this mutation, compared with 30%-40% of Asian patients. Currently, AstraZeneca claims that Tagrisso is the only targeted therapy to prove its potential to treat EGFR-mutated NSCLC at all stages of the disease. GlobalData estimates that the drug’s sales will peak in 2031 at just over $9.3bn.
Etcamah’s breast cancer miss
While Enhertu and Tagrisso may have seen success in the DESTINY-Lung04 and ADAURA trials, Etcamah data was not so positive, as the breast cancer drug failed to meet its primary endpoint in the late-stage SERENA-4 study (NCT04711252), which was looking at the drug’s potential in treatment-naïve patients with oestrogen receptor (ER)-positive, HER2-negative advanced breast cancer.
During the trial, AstraZeneca put its selective oestrogen receptor degrader (SERD) plus Pfizer’s Ibrance (palbociclib) head-to-head against Ibrance and the hormone therapy, anastrozole—finding that the investigational combination did not significantly improve PFS.
However, patients did experience a numerical improvement in this setting. This led Galbraith to say: “Whilst we are disappointed by the SERENA-4 outcome, it sharpens our focus on maximising the number of patients who can benefit from Etcamah today based on SERENA-6 and reinforces the importance of ESR1 testing for patients on first-line therapy.”
Despite this setback, Galbraith touts early breast cancer as an “important opportunity” for Etcamah, as the company forges on with the ongoing Phase III CAMBRIA programme. This duo of Phase III trials is currently looking at Etcamah’s potential in both intermediate-risk and high-risk patients receiving treatment post-surgical removal—focusing on the drug’s effectiveness as a monotherapy, combined and as a follow-on treatment from CDK 4/6 inhibitors.
GlobalData analysts forecast that Etcamah will secure more than $4bn in sales during 2032.
