Real-world experience (RWE) of safety and efficacy of 6-weekly pembrolizumab 400mg (pem6w) plus axitinib (axi) in patients (pts) with advanced renal cell carcinoma (aRCC).

Abstract

309 Background: The KEYNOTE 426 trial demonstrated pem 200mg plus axi twice daily (bd) is effective in aRCC. Pharmacokinetic modelling of pem 400 mg every six weeks demonstrated similar observed exposures to pem 200 mg every three weeks. In NHS Scotland, pem6w + axi was used during the COVID-19 pandemic to reduce hospital visits and for pts’ convenience. Here, we evaluate the RWE of pem6w + axi in aRCC. Methods: Electronic medical records of pts on pem6w + axi between 1 May 2020 & 1 Jun 2021 in two large cancer centers in Scotland were analyzed retrospectively for pts’ characteristics, treatment related adverse events (TRAE) and efficacy. Results: Total of 93 pts were identified (Table). At data cut off of 8 Sep 2021, with a median follow-up of 7 months (mo) (inter-quartile range (IQR) 5 mo; range 0-15 mo), 73 pts (78%) were alive. Clinician assessed radiological response was evaluable in 87 pts. Overall response rate (ORR) including partial response + complete response was noted in 49 pts (56%) with median time to response of 80 days (d). Clinical benefit rate including pts with ORR and stable disease was seen in 72 pts (83%). At data cut off, 24 pts (26%) had progressed with a median time to progression of 117 d (IQR: 85d). Median overall and progression free survival were not reached and follow-up continues. 81 pts (87%) had any grade and 28 pts (30%) had grade 3/4 TRAE. Immune related AE (irAE) of any grade occurred in 60 pts (65%) and grade 3/4 in 19 pts (20%). Common grade 3/4 irAE were transaminitis (10%), colitis (8%), nephritis (2%) and skin (2%). 28 (30%) and 14 pts (15%) respectively required steroids and hospitalisation for irAE with median hospital stay 6 d (range: 2-43 d). 10 pts suffered a second irAE requiring steroids and 5 pts had a second hospital stay with median hospital stay of 6 d. Any grade AE and grade 3/4 AE related to axi occurred in 67 (72%) and 14 pts (15%) respectively. Axi dose was escalated from 5mg to 7mg bd in 12 pts (13%), reduced to 3mg bd in 35 pts (38%) and 2mg bd in 10 pts (11%). 21pts (23%) on Pem and 15pts (16%) on axi discontinued treatment due to TRAE. Conclusions: Our RWE demonstrates that pem6w + axi appears to have comparable safety profile to pem 200mg + axi reported in Keynote 426 study, with the added benefits of less frequent hospital visits. Further follow up continues for efficacy in this heterogeneous pts population. Pt characteristics, total=93 (%).[Table: see text]