title: The cessation of anti-PD-1 antibodies of complete responders in metastatic melanoma.
abstract: The optimal duration of PD-1 antibodies for metastatic melanoma is unknown. In previous trials, there has been the potential to cease therapy if the patient achieves a complete response (CR). We aimed to assess the outcomes of patients who had ceased anti-PD-1 antibodies in this setting. A retrospective review was carried out of CR to PD-1-based therapy across two institutions. Patients were from the Pembrolizumab Named Patient Program (PEM NPP), Nivolumab monotherapy (NIVO), and reimbursed Pembrolizumab (r PEM). Patients had to have experienced a CR to PD-1-based therapy and ceased therapy because of this. Disease recurrence was the primary outcome measured. Twenty-nine patients (PEM NPP, N=20; Nivo, N=3; r PEM, N=6) ceased anti-PD-1 therapy after CR for observation. The median age was 64 (27-83) years. All patients had treatment discontinued for observation. The median time to CR was 10.5 months in the PEM NPP, 7.5 months on r PEM groups, and 17 months in the NIVO group. The median time off therapy in PEM NPP was 10 months, NIVO was 9 months, and r PEM was 4.5 months. To date, three patients have shown a relapse at a median follow-up off treatment of 8 months. This is the first report of patients who have intentionally ceased PD-1-based therapy because of CR. With a follow-up of 8 months off treatment, the risk of relapse was low. Data such as these are clinically relevant as we need to be able to discuss cessation of therapy and relevant from a pharmacoeconomic perspective, given the cost of PD-1 antibodies to society.
authors.affiliation: aDepartment of Medical Oncology, Princess Alexandra Hospital bDepartment of Medical Oncology, Greenslopes Private Hospital cSchool of Medicine, University of Queensland, Brisbane, Queensland, Australia.
authors.forename: Rahul
authors.initials: R
authors.lastname: Ladwa
authors.forename: Victoria
authors.initials: V
authors.lastname: Atkinson
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D061067:Antibodies, Monoclonal, Humanized / Q000627:therapeutic use*; D000074322:Antineoplastic Agents, Immunological / Q000627:therapeutic use*; D005500:Follow-Up Studies; D006801:Humans; D008545:Melanoma / Q000188:drug therapy* / Q000556:secondary; D008875:Middle Aged; D000077594:Nivolumab; D012008:Recurrence; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000473:pathology; D013997:Time Factors; D028761:Withholding Treatment
chemical_list: D000911:Antibodies, Monoclonal; D061067:Antibodies, Monoclonal, Humanized; D000074322:Antineoplastic Agents, Immunological; D000077594:Nivolumab; C582435:pembrolizumab