It's my pleasure to be here presenting you quick summaries of the major renal cell carcinoma studies presented at ASCO GU 2021. Although we weren't able to meet with our friends, collaborators, and mentors in person this year, ASCO GU has been an outstanding experience with cutting-edge science, and practice-changing clinical trials, and many virtual networking opportunities.
I'd like to start with PAPMET, which is a large cooperative group trial led by Dr. Sumanta Pal. This study was also simultaneously published in The Lancet. This was a randomized, multi-arm clinical trial comparing sunitinib with MET inhibitors cabozantinib, crizotinib, and savolitinib in first-line treatment of papillary renal cell carcinoma patients. The crizotinib and savolitinib arms were terminated early due to an interim analysis showing that crizotinib and savolitinib arms were statistically unlikely to perform better than sunitinib.
Overall, 46 patients were assigned to the sunitinib arm, and 44 patients were assigned to the website cabozantinib arm. The study met its primary endpoint and showed improved progression survival with cabozantinib compared to sunitinib. While patients treated with cabozantinib had progression for survival of nine months, the patients treated with sunitinib had a progression-free survival of 5.6 months. In addition, overall response rate was 4% in sunitinib arm and 23% in cabozantinib arm.
At this point, I should underscore that papillary RCC is a rare subtype and comprises only 15% to 20% of renal cell carcinomas. So the investigators here really deserve an applause for successfully completing a very challenging study and providing a new first-line treatment for patients with papillary renal cell carcinoma.
My second highlight is the CLEAR trial. This study was simultaneously published in the New England Journal of Medicine. In this trial, a combination of pembrolizumab and lenvatinib was compared with combination lenvatinib/everolimus, which is actually an improved regimen in a first-line treatment of RCC, and compared with sunitinib, which is the universal comparator of first-line studies in renal cell carcinoma.
Over 1,000 patients were enrolled. Briefly, combination pembrolizumab and lenvatinib showed significant progression-free survival benefit and overall response rate benefit over sunitinib. Progression-free survival was 21.3 months, with a hazard ratio of 0.29. And objective response rate was 71% with the pembrolizumab and lenvatinib combination. Actually, 16% of the patients had complete response, which is the highest we've seen so far.
So we actually have seen the highest flying progression-free survival curve that we have seen in first-line treatment of renal cell carcinoma so far. Of course, I have to highlight here that cross-trial comparisons can be misleading. These results are, regardless, outstanding. There were concerns regarding the tolerability of the lenvatinib at 20 milligram, as 68% of the patients had dose reduction. But it looks like, after the adjustment to dose, this group of patients were able to obtain a progression-free survival for more than 20 months.
We'll probably see further investigations in the future elaborating patient-reported outcomes and tolerability. This is a practice-changing study. And right now, with the results of the CLEAR study, we have one more option for our patients which is superior to sunitinib in multiple parameters, including progression-free survival, overall response rate, and overall survival.
My last highlight is the phase II study of combination belzutifan and cabozantinib presented by Dr. Choueiri. Belzutifan is a new name for most of us. It is an inhibitor of HIF-2 alpha, which plays a key role in pathophysiology of renal cell carcinoma. In brief, renal cell carcinoma pathophysiology starts with functional loss of BHL gene. And this, in turn, causes an impaired ubiquitination and accumulation of hypoxia-inducible factors, also known as HIFs. This causes an increase in the production of several growth factors that play key roles in progression of renal cell carcinoma.
Until now, we have been treating growth factors and the receptors with targeted therapies. We've also treated the immune system itself to treat renal cell carcinoma. And now, actually, we are targeting the root cause of the problem with belzutifan. This is extremely exciting news. Dr. Choueiri presented the outcomes in the cohort two of the study.
For this cohort, patients who were previously immunotherapy treated and/or VEGF-TKI treated were included. They're very early results as the median follow-up was around 11 months at the time of the presentation. But objective response rate was 22%, and 88% of the patients experienced a reduction in target lesions. Disease control was achieved in 90% of the patients. And median progression-free survival was 16 months.
Those are very promising results, especially considering that the patient population was previously treated. We'll be looking forward to the results of the cohort one, which enroll treatment-naive patients.
Those are my highlights from the ASCO GU '21 meeting, but I urge all of you to have a detailed look at the translational evidence elaborating cancer genomics, radiomics, and microbiome presented at ASCO GU '21, as well. We have seen excellent presentations in ASCO GU '21, especially in the area of rare types of renal cell carcinoma, certain subpopulations, such as elderly patients, and patient-reported outcomes.
I'd like to thank you for inviting me, and also thanking investigators and research teams for their amazing contribution to science and well-being of our patients. Thank you.