The second day of ESMO included the oral genitourinary (GU) oncology session that focused on renal cell (kidney) and urothelial (bladder) carcinoma.
Several years ago, the SWITCH study evaluated the sequence of sunitinib and sorafenib showing similar overall progression free survival and overall survival regardless of the order by which each drug was utilized. At ESMO 2017, results of the SWITCH-II trial were presented. This study tested the sequence of pazopanib and sorafenib in patients with advanced RCC of any histology (i.e. clear cell or non-clear cell). The study sought to enroll 544 patients, but stopped after 377 patients due to slow accrual. Only half of the patients remained on study and switched to their assigned drug after tumor growth on drug #1. Overall, while the study didn’t complete planned accrual, there was a trend for improved progression-free and overall survival for the pazopanib → sorafenib sequence.
Historically when most patients were treated with cytokines (IL-2 and interferon), two randomized trials by U.S. and European cooperative groups showed that in the setting of metastatic kidney disease, patients live longer by first removing the kidney mass and then treating with interferon rather than treating with interferon without removal of the kidney. Since the introduction of new therapies in late 2005 which have higher rates of tumor shrinkage and longer lifespans for patients, it is unknown if patients should still have their kidney tumor removed prior to drug therapy.
In the EORTC 30073 SURTIME trial, European investigators decided to try to assess whether tumors remained under control longer and patients lived longer if surgery was performed first or if patients initiated sunitinib for 3 cycles prior to cytoreductive nephrectomy. Because enrollment was slow, the study design was changed to assess the percent of patients that were free of tumor progression at 28 weeks. Ninety-nine patients were randomized to immediate versus delayed surgery, most with large kidney tumors and intermediate-risk cancer. Overall there was no difference in the percent with cancer progression at 28 weeks with either approach. With the caveat of a small study, there were trends for longer survival and less surgical complications in those with delayed surgery. While the amended study is not able to prove that delayed surgery is the better approach, it gives comfort for those physicians/patients that the choice to initiate medical therapy and then re-evaluate for surgery is acceptable. We await the results of the larger CARMENA study that is testing surgery followed by drug versus drug alone (with no surgery) to see if removal of the primary kidney tumor is necessary.
Additionally, two early-phase studies of novel drug combinations of immunotherapy + targeted therapy were presented. In a phase I study led by the NCI, the safety of the combinations of cabozantinib/nivolumab and cabozantinib/nivolumab/ipilimumab were tested in patients with a number of different treatment-refractory tumor types, especially urothelial and other types of bladder cancers. Overall, both combinations were deemed to be safe and are moving forward in a phase III trial. However, many toxicities did occur and most patients needed to reduce the dose of at least one drug so these combinations should only be used in a clinical trial setting.
The phase II portion of a phase I/II study testing the combination of lenvatinib + pembrolizumab. The initial (phase 1) portion of the study presented at ESMO 2016 determined the safe dose in patients with different types of tumors (mostly RCC). This year, new results were presented with 22 additional patients added to the 8 previously treated on the phase I portion. Overall, there was an impressive tumor response rate of 63%, with 83% significant tumor shrinkage in those patients treated in the 1st line setting. This combination is also being tested in a phase III study for patients with advanced RCC which will soon be opening at Weill Cornell Medicine and NewYork-Presbyterian.
What's New in GU? 