- Daiichi Sankyo will ask the Food and Drug Administration to approve an experimental lung cancer antibody drug after mid-stage trial data showed it shrank tumors in about one-third of study participants with advanced disease, the company said Monday.
- The data, detailed at a lung cancer conference and published in a medical journal, were from patients whose cancer has a mutation called EGFR and has progressed following chemotherapy and an EGFR-targeting drug. Trial participants, who otherwise have few treatment options, went a median of six months without their disease progressing following treatment with the drug, called patritumab deruxtecan.
- If approved, patritumab deruxtecan could be the next so-called antibody-drug conjugate to emerge from Daiichi Sankyo’s laboratories to treat cancer. The first, the AstraZeneca-partnered Enhertu, has been approved to treat breast, lung and gastric cancer.
Treatment for non-small cell lung cancer has transformed over the past decade due to the arrival of immunotherapies like Merck & Co.’s Keytruda and targeted drugs for tumors driven by specific mutations. Mutations in the EGFR gene are common, and have helped direct treatment since the approval of AstraZeneca’s Iressa 20 years ago.
Since then, drugmakers have developed several more EGFR-targeting drugs, and AstraZeneca’s newer Tagrisso is now standard therapy.
Tumors can develop resistance to targeted therapies, however. Once patients progress following chemotherapy and a targeted agent there are few good options, and EGFR patients fare poorly when treated with immunotherapies.
Patritumab deruxtecan has secured a Breakthrough Therapy designation from the FDA, which is meant to speed the testing and review of promising treatments.
Antibody-drug conjugates like patritumab deruxtecan and Enhertu combine a protein-targeting antibody with a toxic chemical to directly target tumor cells. The approach can be more potent, as well as limit side effects. Patritumab deruxtecan targets a protein called HER3 that is also present in breast cancer.
Daiichi Sankyo enrolled 277 patients in its trial, called HERTHENA-Lung02. Only one patient treated with patritumab deruxtecan was judged to have had a complete response, meaning elimination of all tumors, while all other responses were classified as partial. Patients survived a median of 12 months following treatment, researchers found.
Response rates were similar in patients treated with older EGFR drugs and those treated with a third-generation drug.
Nearly two-thirds of trial participants had side effects that were serious and needed medical attention, most commonly a drop in platelet and white blood cell counts. Twelve patients had a type of lung scarring that also occurred in those who received another Daiichi Sankyo antibody drug conjugate.
Daiichi Sankyo said it plans on submitting patritumab deruxtecan to the FDA by the end of its 2023 fiscal year, which ends on March 31, 2024. The data were presented at the World Conference on Lung Cancer and published in the Journal of Clinical Oncology.
With AstraZeneca, Daiichi Sankyo is also developing another antibody-drug conjugate for lung cancer, called datopotamab deruxtecan and aimed at a target known as TROP2.