AstraZeneca’s oncology portfolio posted a mixed set of results late last week, with two lung cancer medicines securing a major Phase III win while a breast cancer therapy missed its primary endpoint.
Enhertu sets new standard in lung cancer
The company’s co-developed antibody drug conjugate, 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). In the Phase III DESTINY-Lung04 study, Enhertu significantly improved progression-free survival (PFS) over the current SoC of chemotherapy plus Keytruda.
Patients receiving Enhertu saw a 37% reduction in the risk of disease progression or death, extending median PFS to 14.3 months compared to 8.3 months with the control treatment. The objective response rate was 70% versus 44.5% in the SoC arm. The results were presented at the IASLC’s ongoing 2026 World Conference on Lung Cancer in Seoul.
HER2 mutations occur in roughly 2% to 4% of NSCLC cases but are linked to a poor prognosis, with only about one in ten patients living beyond five years. The data showed favourable PFS trends across key subgroups, including those with cancer that had spread to the brain and liver. This marks the first therapy to demonstrate superior PFS benefits to the SoC in this specific patient population, a fact that oncology and haematology EVP Susan Galbraith says highlights the drug’s potential in newly diagnosed metastatic patients.
The industry analyst GlobalData forecasts the drug will generate just under $13bn in sales by 2032.
It is a different story for Tagrisso. The EGFR tyrosine kinase inhibitor showed sustained benefits in the Phase III ADAURA study, where patients received either Tagrisso or placebo after surgery to remove EGFR-mutated NSCLC. At an eight-year follow-up, Tagrisso reduced the risk of death by 47% across all predefined subgroups. Principal investigator Roy Herbst described the results as particularly impressive due to high rates of crossover to Tagrisso following disease recurrence. The results reinforce the importance of prioritising EGFR testing at diagnosis.
Real-world evidence also highlighted the benefits of finishing Tagrisso’s three-year treatment course, showing those who discontinued early were more than twice as likely to experience disease recurrence or death. AstraZeneca claims Tagrisso is the only targeted therapy to prove its potential to treat EGFR-mutated NSCLC at all stages of the disease, with GlobalData estimating peak sales of just over $9.3bn in 2031.
This year’s data highlights a familiar pattern in oncology trials: targeted therapies often show their strongest results when given as a first-line treatment or immediately after surgery, rather than after multiple rounds of previous therapies have already failed.
Etcamah misses the mark in breast cancer
The company’s breast cancer therapy, Etcamah (camizestrant), did not fare as well. In the late-stage SERENA-4 study, the selective oestrogen receptor degrader plus Pfizer’s Ibrance failed to significantly improve progression-free survival compared to Ibrance and anastrozole in treatment-naïve patients with ER-positive, HER2-negative advanced breast cancer.
While the primary endpoint was not met, patients did experience a numerical improvement in this setting. Galbraith noted that the outcome “sharpens our focus on maximising the number of patients who can benefit from Etcamah today based on SERENA-6.” She also emphasized the importance of ESR1 testing for patients on first-line therapy.
AstraZeneca looks to future breast cancer trials
Despite the setback in the SERENA-4 study, the company maintains that early-stage breast cancer remains an “important opportunity” for Etcamah. AstraZeneca is pursuing this avenue through the ongoing Phase III CAMBRIA programme, which tests the drug’s potential in two specific settings. One trial focuses on patients with intermediate-risk disease, while the other targets high-risk patients following surgical removal of the tumour.
The CAMBRIA trials are examining Etcamah in three different roles: as a standalone treatment, in combination with other therapies, and as a follow-on treatment after patients have finished CDK 4/6 inhibitors. This structured approach aims to validate the drug’s efficacy across various stages of the disease timeline.
GlobalData analysts predict that Etcamah could generate more than $4bn in annual sales by 2032. This forecast suggests that the company hopes to recover from the missed primary endpoint by capturing market share in other breast cancer indications.
