In addition to missing the mark in overall survival, Gilead reported Thursday a higher number of deaths in the Trodelvy arm of the confirmatory metastatic urothelial cancer study.
Gilead Sciences announced on Thursday that its antibody-drug conjugate Trodelvy failed to reach the primary endpoint in a confirmatory Phase III study in patients with locally advanced or metastatic urothelial cancer, marking another setback for the treatment.
The Phase III TROPiCS-04 trial pitted Trodelvy against single-agent chemotherapy treatments that were chosen by a physician in metastatic urothelial cancer (mUC) patients who had already received platinum-containing chemotherapy and an anti-PD-(L)1. The study did not meet the primary endpoint of overall survival (OS) in the intention-to-treat (ITT) population.
Still, Gilead touted a “numerical improvement” in OS in Trodelvy’s favor as well as “trends in improvement for select pre-specified subgroups.”
The secondary endpoints of progression-free survival (PFS) and overall response rate (ORR) also showed some improvement, according to Gilead. However, no data were immediately available with the company announcing that they will be presented at an unspecified medical meeting.
In the TROPiCS-04 trial, Gilead also reported a higher number of deaths in the Trodelvy arm due to adverse events. While no numbers were provided, the company said that the deaths were primarily observed early in treatment and related to “neutropenic complications” including infection.
The pharma said it is investigating the data, will discuss the next steps with the FDA and will work with physicians to reiterate the “importance of granulocyte-colony stimulating factor (G-CSF) use” for preventing neutropenic complications. The company also noted that there have been no changes to the Trodelvy’s known safety profile for its approved use in breast cancer.
However, Trodelvy has a boxed warning for severe or life-threatening neutropenia. The treatment also has an accelerated approval indication for patients with mUC. Gilead noted that continued approval in this indication is “contingent upon” verification and description of clinical benefit in confirmatory trials.
An analyst report from the Bank of Montreal Capital Markets noted that bladder cancer is a “smaller fraction” of Trodelvy’s revenue base but the results are “problematic” for further expansion into mUC.
According to Jefferies analysts, investor sentiment regarding Gilead’s stock “remains tough” especially as Trodelvy missed the primary endpoint of a Phase III trial for non-small cell lung cancer in January 2024, failing to significantly improve OS.
“The continued pipeline disappointments do continue to raise the buzz of many hedge funds and other investors about the overall strategy and [business development] success in the last few years and especially versus other large pharma peers,” the Jefferies analysts wrote.
Tyler Patchen is a staff writer at BioSpace. You can reach him at tyler.patchen@biospace.com. Follow him on LinkedIn.