In addition to auditing our local practice of prescribing sunitib, the purpose of the study was to evaluate and compare the safety, efficacy and tolerability of the 4 weeks on and 2 weeks off regime (4:2), which is currently considered to be standard of practice to the 2weeks on and 1 week off regime (2:1), in patients with metastatic renal cell carcinoma.
Between the years 2014-2017, 58 patients with metastatic renal cell carcinoma receiving Sunitib, were identified via the electronic patient records and chemotherapy prescribing database.
33 patients had clear cell carcinoma, 14 papillary cell carcinoma, 1 chromophobe and rest were unidentified. 37 patients were male, 20 were female. Median age for the cohort was 64 (range 41-84 years). Female median age was 52 (range 41-83 years). The median age for the males was 69 (range 59- 84 years). 45 patients had sunitinib as first line treatment. 12, had previous treatment with pazopanib, axitinib, cisplatin/gemcitabine, bevacizumab/atezolizumab. 21 were commenced on Sunitinib 50mg (4:2) (Group A). 15 on 50mg 2:1(Group B).11 on 37.5mg (2:1) (Group C), due to previous haematological, hepatic toxicities on pazopanib and borderline performance status. Group A: 9(42.8%) dose reduced to 37,5mg (4:2) due hand and foot syndrome (n = 3), haematological toxicities (n = 2), fatigue(n = 1), mucositis (n = 1), hepatotoxicity(n = 1). 10(47.6%) changed to 2:1 due to fatigue (n = 7), diarrhoea (n = 1), hand- foot syndrome (n = 1), Oedema (n = 1). Side effects presented between cycles 1-6. 12(57%) progressed between cycles 2-18 .4(19%) treatment termination due to grade 3 fatigue and hand foot syndrome. Group B: 5(33.3%) dose reduced between cycles 6-36 to 37.5mg (2:1) due to fatigue (n = 1), diarrhoea (n = 1), thrombocytopaenia (n = 1), Mucositis (n = 1). 5 (33.3%) progressed between cycles 4-46. 1 terminated at cycle 6 due to nephrotic syndrome. Group C: 3 (27.2%) further dose reductions to 25mg (2:1) due to arthralgia (n = 1), Fatigue(n = 1), thrombocytopaenia (n = 1). 2 (18%) progressed at cycles 0.8-2.
Group A had earlier presentation of side effects compared to group B and C, with a higher incidence of hand and foot syndrome and of grade 3 side effects leading to termination of treatment. Based on these results, we would recommend that 2:1 is safe to be adopted as standard of care.
Royal Free
Has not received any funding
All authors have declared no conflicts of interest.