MITF translocation renal cell carcinoma (tRCC) is a rare RCC subtype harbouring TFE3/TFEB translocations with poor prognosis and no standard of care in metastatic setting. Program death ligand-1 (PDL-1) expression was reported in 90% of cases prompting us to analysed the benefit of immune checkpoint inhibitors (ICI) in this population.
A multicenter retrospective study was conducted to identify patients with MITF family tRCC who had received ICI in referral centres in France and USA. In the majority of cases, the diagnosis was confirmed by FISH. Overall response rate (ORR) according to RECIST criteria, progression-free survival (PFS) and overall survival (OS) were analyzed.
Overall, 23 patients (4 males and 19 females) with metastatic disease were identified in 12 institutions (median age 33.5 years), all receiving ICIs as 2nd or later line. For first-line treatment, 19 (82.6%) patients received vascular endothelial growth factor receptor (VEGFR) inhibitors with a median PFS on therapy of 3 months (range, 1-22 months) and 2 (10.5%) responders. Regarding ICI, 19 patients received Nivolumab, 3 patients Ipilimumab and 4 patients combinations of ICIs +/- VEGFR inhibitors. Median PFS for patients under first ICI administered was 2.45 months (range, 1-40 months); among those, 4 patients experienced partial responses (17.4%) and 2 patients (9.5%) a stable disease with a median PFS of those responders under ICI of 9 months (range 8,3-30), similar to the first line PFS with VEGFR inhibitors [9 months, (range 1-22)]. One patient with partial response to Ipilimumab lasting for 9 months showed hyperprogressive disease following treatment by Nivolumab. With a median follow-up of 19 months, median OS was 23.5 months.
MITF family tRCC is an aggressive disease with occasional responses to ICI. Valid targets and clinical trials remain warranted in this disease.
Clinical trial identification
Legal entity responsible for the study
Pitié Salpétrière hospital
S. Oudard: Reports personal fees from Bristol-Myers Squibb, personal fees from Merck, personal fees from Ipsen, personal fees from Novartis, personal fees from Pfizer, outside the submitted work. M. Voss: Consulting: Exelixis, Novartis, Eisai, Calithera, Alexion, Research funding: Genentech, Bristol-Myers Squibb M.A. Bilen: Exelixis: advisory board. T.K. Choueiri: Consulting: AstraZeneca, Bayer, Bristol-Myers Squibb, Cerulean, Eisai, Foundation Medicine Inc, Genentech, GSK, Merck, Novartis, Research funding: AstraZeneca, Bristol-Myers Squibb, Genentech, GSK, Novartis, Peloton, Roche, Pfizer, Tracon, Eisai, Exelixis, merck. G. Malouf: consulting: Pfizer, Novartis, Bristol-Myers Squibb research grant: Pfizer, Novartis. All other authors have declared no conflicts of interest.