MedCity News recently carried an announcement by Gilead Sciences that its drug, Trodelvy, fell short of its main goal of overall survival in a bladder cancer study. Trodelvy is an antibody drug conjugate (ADC) that received the FDA’s accelerated approval in 2021 for its performance against metastatic urothelial (bladder) cancer affecting the lining of the urinary tract.
ADCs bind to certain proteins on cancer cells as well as other cells. The drug invades the cells selectively and kills them leaving the other cells unharmed. Metastatic cancer occurs when cells break away from tumor walls and travel to other parts of the body. Compared to chemotherapy, the drug did not benefit patients who had advanced bladder cancer by extending overall survival. Now the accelerated approval may be in jeopardy as this is the second recent disappointment for Trodelvy after its failure in a separate and critical study of lung cancer.
About Targeted Therapies
The drug’s antibody element targets TROP-2 which is a protein found in abundance on the surface of various cancer cells. The drug received approval in 2020 to treat triple-negative breast cancer. Then in 2021 the drug received accelerated approval to treat metastatic urothelial cancer which is aggressive and has low survival rates.
About the Trial
Trodelvy is an antibody drug conjugate (ADC) that targets the protein TROP-2 which is found on the surface of various cancer cells.
For the study, 711 patients with advanced bladder cancer were enrolled in the referenced Phase 3 test (the Confirmatory Test). The participants’ cancer had spread after they were treated with platinum chemotherapy plus immunotherapy called checkpoint inhibitor. Trodelvy was compared against any one of three standard choice chemotherapies. The primary goal was improvement in overall survival.
Adverse Events
Gilead reported Trodelvy related deaths due to adverse events early in treatment when compared to comparable chemotherapy treatment. The deaths were associated with lower levels of neutrophils (neutropenia) exposing the patient to infections. Trodelvy’s label flags this issue. It cautions physicians to become familiar with granulocyte colony stimulating factor therapies whereby proteins stimulate bone marrow in the production of neutrophils.
Follow-Up
In post-trial analysis, Gilead stated that there were numerical improvements towards its goal of overall survival for Trodelvy patients. Additionally, Gilead said, favorable trends emerged in certain subgroups which included patients who had been previously treated with a checkpoint inhibitor and chemotherapy.
The FDA takes a rigid stance against allowing drugs that fail their confirmatory trials to remain on label. Therefore, several analysts have expressed their view that it is unlikely the agency will continue to support its approval of Trodelvy to remain on label for urothelial cancer.
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bladder cancer clinical trial research treatment
Last modified: August 19, 2024
