Lonsurf (trifluridine/tipiracil): Assessing the impact of dose related toxicities and progression free survival in (refractory) metastatic colorectal cancer

In the RECOURSE trial which lead to its accreditation, Lonsurf (trifluridine/tipiracil) was shown to extend progression free survival (PFS) by 1.8 months in metastatic colorectal cancer. This Trust audit aims to assess the average quantity of cycles of Lonsurf received by participants and the length of time it extends PFS. Similarly, to identify how many participants required a dose-reduction or experienced toxicities which necessitated supportive therapies. Quantitative data was collected retrospectively from all participants who had received >= 1 cycle of Lonsurf from The Clatterbridge Cancer Centre (CCC) from 2016 until June 2020. Participant electronic patient records were accessed to identify toxicity grading, length of treatment received, the date progression was identified, if dose reductions were applied and if supportive therapies were administered. Lonsurf extends PFS in patients with metastatic colorectal cancer at CCC by 3.0 months (95% CI: 2.73-3.27) and average treatment length was 2.4 months. However, 78 participants (41.5%) received a dose reduction due to toxicities. A total of 955 toxicities were recorded by participants; the most commonly reported toxicities irrespective of grade were fatigue (33.8%), diarrhoea (13.8%) and nausea (12.3%). The most common grade >= 3 toxicities were constipation and infection. The most frequently utilised supportive therapies were loperamide (49.6%) and domperidone (49.1%). Granulocyte colony stimulating factor (GCSF) was required by patients on 5 occasions (0.3%) in total. Lonsurf extends median PFS in patients with metastatic colorectal cancer by 3.0 months. The most common grade >= 3 toxicities which necessitated supportive therapies or a dose reduction were gastrointestinal and infection.