JNJ-6420 (radiopharmaceutical)

2024: Death of four patients

At the end of May 2024, Johnson & Johnson released the results of the first phase of clinical trials of the radiopharmaceutical JNJ-6420, designed to treat prostate cancer. The drug has shown promising efficacy, but four patients treated with this therapy have died.

Drug JNJ-6420 is intended for treatment of metastatic prostate cancer resistant to castration. It is a targeted antibody-based radiation therapy against hK2 that acts by delivering an actinium-based radioligand. The payload emits high-energy, short-range alpha particles targeting cancer cells.

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The phase one clinical trial reportedly involved 57 people who received JNJ-6420 intravenously at a dose of 150 μCi or higher. 35 of them had Grade 3 or higher treatment-related adverse events. In particular, thrombocytopenia (a pathological condition characterized by a decrease in the blood composition of platelets) and interstitial lung diseases (lesions of pulmonary parenchyma, which are based on diffuse inflammatory lesions of the alveoli, distal bronchi and capillaries of the lungs with an outcome in fibrosis) were noted.

Nine patients are said to have dropped out of the study due to treatment-related adverse events. Common issues included anemia and abnormal white blood cell count reduction. Approximately 37% of patients experienced serious adverse events.

During the first phase of the study of JNJ-6420, a targeted radiopharmaceutical for the treatment of metastatic, castration-resistant prostate cancer, four deaths were recorded, which, despite its promising effectiveness, indicates problems with the safety of the drug, the report says.[1]

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