A recently approved antibody-drug conjugate provides another much-needed treatment choice for patients with locally advanced and metastatic urothelial cancer.
The Food and Drug Administration (FDA) granted accelerated approval to Trodelvy (sacituzumab govitecan-hziy) in April for the treatment of locally advanced and metastatic urothelial cancer, giving patients another option if they did not respond to platinum-based chemotherapy or immunotherapy.
In particular, antibody-drug conjugates, which are a form of immunotherapy, utilize monoclonal antibodies linked to a drug that bind to specific proteins to kill cancer cells without harming other cells. Before the FDA approval, this patient population had few options if the cancer did not respond to chemotherapy or PD-1 or PD-L1 antibodies, another form of immunotherapy.
“We had an antibody-drug conjugate called enfortumab vedotin (Padcev), which was approved in 2019, (but) there are now patients who cannot receive that due to preexisting severe neuropathy,” said Dr. Shilpa Gupta, director of genitourinary medical oncology at Cleveland Clinic, in an interview with CURE®. “(For) those who progressed on (Padcev), there are very limited options still. … (Trodelvy) is certainly an option that is promising for these patients who historically did not have any.”
Trodelvy was previously approved by the FDA for another indication: triple-negative breast cancer.
“A lot of doctors have been using (Trodelvy) in the community, but there’s not a whole lot of awareness about it for urothelial cancer,” Gupta said.
This recent FDA approval for locally advanced and metastatic urothelial cancer is based on findings from the TROPHY clinical trial, which assessed the effect of Trodelvy in 112 patients with locally advanced or metastatic urothelial cancer who had received prior treatment with platinum chemotherapy and either anti-PD-1 or PD-L1 based immunotherapy. Treatment with Trodelvy contributed to an overall response rate of 27.7% and a median duration of response of 7.2 months.
“If you look at it in the perspective of immunotherapy, which has been (a) really very powerful class of drugs since 2016, those response rates have also only been in the 20% or so range,” Gupta said. “Still, (immunotherapy) is so widely used, but unfortunately, the majority of patients don’t respond to that. … Chemotherapies can achieve (an overall response rate of) 10% to 20% max, and immunotherapy has not done any better in that regard. For these (previously) treated patients, this is in line with what we would see with other therapies.”
Some side effects associated with Trodelvy include neutropenia and diarrhea, both of which can be either prevented or managed, Gupta said, adding that an ongoing phase 3 study is assessing whether the survival improvement from Trodelvy can continue over a longer period of time versus salvage chemotherapy, an approach used if cancer has not responded to other treatments.
More research is also needed to determine the best treatment sequence for patients with locally advanced or metastatic urothelial cancer.
“At some point, we have to be able to use these different therapies available in a patient’s journey,” Gupta said. “Nobody really knows if it is better to give Trodelvy before (Padcev) or vice versa. We also have (an) FGFR3 inhibitor approved (called Balversa [erdafitinib]).
“The sequence question has not really been defined to date. At some point, a patient should be able to receive these different therapies that are approved. And that is what (the Trodelvy approval) represents: an (additional option) for these patients.”
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