Real World Outcomes of First Line (1L) Nivolumab and Ipilimumab (NIVO IPI) in Metastatic Renal Cell Carcinoma (mrcc): an Update from the International Mrcc Database Consortium (IMDC).

395 Background: NIVO IPI is one of several 1L treatment options for mRCC and is limited to intermediate and poor risk disease in many jurisdictions. We report the outcomes of 1L NIVO IPI from the IMDC. Methods: All IMDC patients who received 1L NIVO IPI were retrospectively analyzed. Key outcomes were compared between IMDC risk groups and included overall survival (OS), time to treatment discontinuation (TTD), time to next treatment (TTNT; defined as time from 1L initiation to next treatment) and response rates. Conditional OS by 6- and 12-month survival are described. Results: 1145 patients received 1L NIVO IPI, including 94 favourable, 559 intermediate, and 313 poor risk patients. 818/980 (86%) of patients had clear cell histology and 14% had sarcomatoid features. The median follow up was 20.0 months. 837/1145 (73%) patients had stopped 1L NIVO IPI and 363/1145 (32%) were deceased. Key outcomes of interest are summarized in Table 1. Subsequent 2L therapy was received by 438/727 (60%) patients and was most frequently sunitinib (37%) and cabozantinib (28%). 3L therapy was received by 160/477 (34%) patients, most often cabozantinib (29%). Immune related adverse events were documented in 48% (274/572) of patients. Conditional survival analysis showed that if a patient was alive at 6 months after starting 1L NIVO IPI, they had an 81% likelihood of being alive for an additional year and a 68% likelihood of surviving two years. If alive at 12 months, there was an 81% chance of surviving one additional year and 68% chance of surviving two additional years. If a patient remained on 1L NIVO IPI for 6 months, there was a 91% likelihood of being alive for one additional year and 76% likelihood of being alive for two years. If they remained on NIVO IPI for 12 months, there was a 94% chance of being alive for one additional year and an 84% chance of surviving two additional years. Conclusions: This large cohort of real-world patients provides benchmark data for clinical trial design and patient counselling, with a median OS surpassing 50 months for intermediate risk patients.[Table: see text]