BackgroundMany interventions to improve a safe use of oral anti-cancer agents have been reported during the last decade. Frequently, these interventions involve nurse-led follow-up, but there is limited data to suggest the proportion of adherence and toxicity related to treatment that nurses can detect. MethodsCAPRI, a randomized phase III trial comparing: an intervention combining Nurse Navigators (NNs) and a mobile application vs. Standard of care in cancer patients treated with oral anticancer agents was initiated in 2016 at Gustave Roussy (Villejuif, France). Nurses conduct regular telephone follow-up (1/week for the 1st month, 2/month for the following 3 months, then 1/3 weeks). During follow-up, they assess adherence, symptoms and supportive care needs. PROMS (Patient Reported Outcome Measure) (e.g. pain, appetite) are also recorded by the patient via the mobile application. A coding grid was developed to extract from the nurses intervention reports the information identified during follow-up and to categorize the actions implemented by them. All regular follow-ups over a 24-month period were studied. ResultsNurses carried out 2279 regular follow-ups concerning 237 patients, of which 1880 could be carried out (patient available). They detected treatment-related symptoms/toxicities (or worsening) in 582 (31%) of the regular follow-ups involving 193 patients. Interventions performed in these situations are advice given to the patient (55%), advice or indications after the oncologist’s request (23%), referral to a primary care professional (14%) or to a health facility (8%). Twenty-six regular follow-ups concerning 18 patients identified adherence issues. Actions implemented by nurses encompassed: patient advice (n=14), request for advice from the referring oncologist (n=10), introduction of a homecare nurse (n=2). ConclusionsClose and proactive nurse-led follow-up might help not only detecting and managing toxicities, but also identifying adherence issues in cancer patients receiving oral anti-cancer agents. Clinical trial identification2016-A00254-47. Legal entity responsible for the studyGustave Roussy. FundingFondation Philanthropia - Lombard Odier, Agence Nationale de la Recherche IHU-MMO, ARS Ile de France, Novartis, AstraZeneca. DisclosureAll authors have declared no conflicts of interest.