A drug combination involving an experimental treatment from AstraZeneca and Daiichi Sankyo has shown early promise in lung cancer, results the two companies believe bolster their recent decision to start a late-stage trial.
Study results presented at the World Conference for Lung Cancer show that a regimen of the companies’ datopotamab deruxtecan and Merck & Co.’s Keytruda, either with or without chemotherapy, had a “tolerable” safety profile and early signs of activity in a small clinical trial of patients with non-small cell lung cancer, the companies said Tuesday.
The datopotamab deruxtecan and Keytruda combination led to a 37% response rate after a median of 6.5 months in the overall study population, which included newly diagnosed patients as well as those who had already received at least one previous treatment. Those two drugs plus chemotherapy led to a 41% response rate after a median 4.4 months. The disease control rate for each, a measure that also includes patients whose disease didn’t progress while on treatment, was 84%, according to AstraZeneca and Daiichi.
Nausea, decreased appetite, anemia and a type of mouth inflammation were the most common side effects reported in testing. There were also four cases of a type of lung scarring associated with another, similar AstraZeneca and Daiichi drug called Enhertu.
The companies haven’t yet reported on more definitive efficacy measures, like how long the regimens keep tumors from spreading or whether patients live longer. Nonetheless, the early findings “support the initiation” of a Phase 3 trial in front-line lung cancer, said Gilles Gallant, the head of Daiichi’s oncology research and development, in a statement. The study, known as TROPION-Lung08, began in March and is expected to produce results in 2026, according to a federal clinical trials database.
The partnership between AstraZeneca and Daiichi is best known for Enhertu. AstraZeneca paid Daiichi nearly $7 billion in 2019 to split rights to the drug, and it’s since been approved in multiple breast cancer settings, most recently becoming the first targeted therapy for “HER2 low disease.” Analysts believe the drug will generate more than $4 billion in yearly revenue by 2026.
Next in line is another, similar drug in datopotamab deruxtecan. Like Enhertu, the medicine is an antibody-drug conjugate, a type of cancer drug that links an antibody to tumor-killing toxin. Also like Enhertu, AstraZeneca in 2020 promised a large sum, up to $6 billion in total payouts, to acquire partial rights.
However, the results the partners reported on Tuesday are for a type of tumor for which cancer immunotherapies like Keytruda have become standard treatments and proven they can extend lives for years. Multiple combinations aiming to boost the effects of immunotherapy have failed to do so after showing early promise. Most recently, a closely watched Roche drug, aimed at a tumor protein called TIGIT, fell short in a Phase 3 trial in May.
AstraZeneca and Daiichi are hoping datopotamab deruxtecan might be different. The drug targets a protein known as TROP2, which is overexpressed in all types of lung cancer and most frequently adenocarcinoma and squamous cell carcinoma, the two most common forms of non-small cell lung tumors. There are no approved TROP2-targeting therapies for lung cancer.
A similar type of medicine developed by Immunomedics and now owned by Gilead is used to treat certain breast cancers. Datopotamab deruxtecan is being tested in breast cancer as well.