Arlene O. Siefker-Radtke, MD, on Metastatic Urothelial Carcinoma: New Data on Erdafitinib vs Chemotherapy From the THOR Study
2023 ASCO Annual Meeting
Arlene O. Siefker-Radtke, MD, of The University of Texas MD Anderson Cancer Center, discusses phase III findings showing that for patients with advanced or metastatic urothelial carcinoma and FGFR alteration who already had been treated with a PD-(L)1 inhibitor, erdafitinib significantly improved overall and progression-free survival, as well as overall response rate, compared with investigator’s choice of chemotherapy (LBA4619).
Transcript
Disclaimer: This video transcript has not been proofread or edited and may contain errors.
Arlene O. Siefker-Radtke:
We now have results from the THOR clinical trial studying erdafitinib in patients who have metastatic surgically unresectable urothelial carcinoma, who've received prior therapy for their tumor. This is the first clinical trial, showing proof of concept benefit from FGF targeted therapy, compared to what's been observed with chemotherapy.
The design of the trial takes patients who've had prior treatment, typically chemotherapy with platinum or carboplatinum, and patients may have had an immune checkpoint inhibitor. There are two cohorts to this trial. The cohort being presented is the group of patients who've had a prior immune checkpoint inhibitor. Patients were randomized between either erdafitinib alone or single agent taxane, or vinflunine, which is approved in Europe. And the results of the trial looked quite good indeed, with it hitting on all three endpoints.
The primary endpoint of the trial was median overall survival, and erdafitinib came in with a statistically significant improvement in overall survival with a median overall survival of 12 months compared to single agent chemotherapy, which was around 7.8 months. We also saw evidence of benefit in progression-free survival and overall survival. The progression-free survival with erdafitinib was around five and a half months. Single agent chemotherapy was half that amount, and the objective response rate for erdafitinib was around 45%, so that's 45% PRs and CRs, while single agent chemotherapy had a response rate of around 11%.
The toxicity reported is similar to what has been observed with other clinical trials of FGF targeted therapy, and as a result of this work, erdafitinib is here to stay as part of the standard armamentarium for the treatment of our urothelial cancer patients.
The ASCO Post Staff
Rana R. McKay, MD, of the University of California, San Diego, and Brian I. Rini, MD, of Vanderbilt-Ingram Cancer Center, discuss the 5-year follow-up results with the combination of a checkpoint inhibitor plus a VEGFR tyrosine kinase inhibitor as first-line treatment for patients with advanced clear cell renal cell carcinoma (RCC). Pembrolizumab plus axitinib continued to demonstrate improved survival outcomes as well as overall response rate vs sunitinib for patients with previously untreated disease (Abstract LBA4501).
The ASCO Post Staff
Nirav N. Shah, MD, of the Medical College of Wisconsin, discusses the efficacy and safety of pirtobrutinib, a highly selective, noncovalent BTK inhibitor, studied for more than 3 years in the BRUIN trial. The results showed that the use of pirtobrutinib continues to have durable efficacy and a favorable safety profile in heavily pretreated patients with relapsed or refractory mantle cell lymphoma and prior BTK inhibitor therapy. Responses were observed in patients with high-risk disease features, including blastoid/pleomorphic variants, elevated Ki67 index, and TP53 mutations (Abstract 7514).
The ASCO Post Staff
Nagla Abdel Karim, MD, of the Inova Schar Cancer Institute, University of Virginia, discusses phase II data showing that maintenance atezolizumab plus talazoparib improved progression-free survival in Schlafen-11–selected patients with extensive-stage small cell lung cancer. This study demonstrated the feasibility of conducting biomarker-selected trials in this disease, paving the way for future evaluation of novel therapies in selected populations (Abstract 8504).
The ASCO Post Staff
Amer Methqal Zeidan, MBBS, MHS, of Yale University and Yale Cancer Center, discusses phase III findings on the first-in-class telomerase inhibitor imetelstat, which was given to patients with heavily transfusion-dependent non-del(5q) lower-risk myelodysplastic syndromes that are resistant to erythropoiesis-stimulating agents. Imetelstat resulted in a significant and sustained red blood cell (RBC) transfusion independence in 40% of these heavily transfused patients. The response was also durable and accompanied by an impressive median hemoglobin rise of 3.6 g/dL, and seen in patients with and without ring sideroblasts. Importantly, reduced variant allele frequency was observed in the most commonly mutated myeloid genes which correlated with duration of transfusion independence and hemoglobin rise, therefore suggesting a disease-modifying potential of this agent (Abstract 7004).
The ASCO Post Staff
Reid Merryman, MD, of Dana-Farber Cancer Institute, discusses his findings on the regimen of epcoritamab plus rituximab and lenalidomide for patients with high-risk follicular lymphoma. Regardless of whether their disease progressed within 24 months of first-line chemoimmunotherapy, this regimen showed antitumor activity and a manageable safety profile in patients with relapsed or refractory disease. Epcoritamab, a subcutaneous T-cell–engaging bispecific antibody, may abrogate the negative effects of high-risk features (Abstract 7506).
