Dr. Zhang on the THOR trial of erdafitinib in urothelial carcinoma

In this video, Tian Zhang, MD, associate professor of Medicine at UT Southwestern Medical Center, discusses the phase 3 THOR trial (NCT03390504), which showed that erdafitinib significantly improved overall survival compared with investigator’s choice of chemotherapy in patients with FGFR2/3-altered metastatic urothelial cancer who had previously received an anti–PD-(L)1 therapy.^1,2

The THOR study is the confirmatory trial supporting a supplemental New Drug Application to the FDA seeking to transition the accelerated approval of erdafitinib in urothelial carcinoma into a full approval.

Video transcript

The THOR trial was a really important phase 3 trial taking patients with metastatic or unresectable urothelial cancer with disease progression on prior PD-1 therapies who were then selected for FGFR alterations in either FGFR2 or FGFR3. And then these patients in particular were randomized 1:1 to receive either the FGFR inhibitor erdafitinib or chemotherapy of choice. Often, these were taxane-based chemotherapies—paclitaxel, docetaxel—or vinflunine, which is approved in Europe. The primary end point was actually overall survival. The study was able to accrue over 260 patients, all molecularly selected, and treated them with FGFR inhibitors in 50% of those patients and chemotherapy in the other half.

Interestingly, we saw an overall survival benefit for erdafitinib compared to chemotherapy. The hazard ratio was right around 0.64 with a median overall survival of about 12 months in patients treated with or erdafitinib compared to only about 7 months for patients treated with chemotherapy. And, you know,

It's important to note that these patients were all molecularly selected. So genomic sequencing for these patients with metastatic urothelial cancer is really important in our treatment selection, and it really does define patients’ ability to receive more life-extending therapies, such as erdafitinib.

Transcript has been added for clarity

References

1. Janssen Submits Supplemental New Drug Application to the U.S. Food and Drug Administration Seeking Full Approval of BALVERSA® (erdafitinib) for the Treatment of Patients with Locally Advanced or Metastatic Urothelial Carcinoma and Selected Fibroblast Growth Factor Receptor Gene Alterations. Accessed August 29, 2023. https://finance.yahoo.com/news/janssen-submits-supplemental-drug-application-201500611.html

2. Loriot Y, Matsubara N, Park SH, et al. Phase 3 THOR study: results of erdafitinib (erda) versus chemotherapy (chemo) in patients (pts) with advanced or metastatic urothelial cancer (mUC) with select fibroblast growth factor receptor alterations (FGFRalt). J Clin Oncol. 2023;41(suppl 17):LBA4619.