Among patients with advanced melanoma who respond to immunotherapy, those who are treated with shorter courses of immunotherapy have responses as durable as those treated with longer courses, according to findings from a single-institution study presented by Grayce Selig, MD, Internal Medicine Resident, University of Pennsylvania, Philadelphia, and colleagues during the 2020 American Society of Clinical Oncology Virtual Scientific Program.
Based on data from KEYNOTE-001, immunotherapy is often continued for 24 months in patients with a confirmed complete response (CR), noted the researchers, but in their review of patients with locally advanced melanoma treated at the Abramson Cancer Center, Philadelphia, those who stopped immunotherapy within 7 months of achieving a CR had a CR that was as durable as those who were treated for >7 months. Shorter courses could potentially reduce costs and toxicity, they speculated.
The researchers identified 45 patients with locally advanced stage III and IV melanoma who received immunotherapy (pembrolizumab [Keytruda], nivolumab [Opdivo], or ipilimumab [Yervoy] plus nivolumab) as first-line or subsequent therapy, achieved a CR, and stopped therapy.
Disease-free survival (DFS), durable CR, and disease recurrence were assessed by duration of therapy (<7 months vs >7 months).
“Seven months was selected as the cutoff in order to capture patients who had an early CR, confirmed by scans 4 weeks apart, and elected to stop treatment early,” the researchers wrote in their poster.
Of the 45 patients, 31 (69%) were men; 8 (18%) had stage III and 37 (82%) had stage IV disease; their median age was 65.3 years; 25 (55.5%) had BRAF wild-type melanoma; and 7 (15.5%) had BRAF-mutant disease (BRAF status was unknown in 13 [29%]).
Twenty-seven (60%) patients stopped treatment before 7 months and 18 (40%) stopped after 7 months. The median time to CR was 4.7 months in those stopping treatment at <7 months. Median time to CR was 11.8 months in those treated for >7 months. Twenty-eight (60%) patients stopped because they achieved CR and 17 (40%) stopped due to toxicity.
Patients who were treated for <7 months had a median DFS from time of CR of 30.4 months (95% confidence interval [CI], 23.7-37.2), compared with a median of 28.0 months among those treated for >7 months (95% CI, 18.9-37).
Patients who stopped immunotherapy due to toxicity had a median treatment duration of 3.7 months. Their median DFS from time of CR was 30.4 months (95% CI, 20.7-40.1).
Patients who stopped because of CR had a median treatment duration of 8.5 months. They had a median DFS of 27.6 months (95% CI, 21.2-34).
Five (11.1%) patients had a recurrence: 1 (5.8%) who stopped due to toxicity and 4 (16.6%) who stopped after CR. The rate of disease recurrence after CR was not significantly different between patients treated with longer treatment courses versus those who stopped therapy prior to 7 months.
“Patients who stopped early due to toxicity and subsequently achieved a CR had no difference in DFS compared to those who were treated until CR,” the researchers noted.
Source: Selig GN, Chi Huang AC, Karakousis GC, et al. Landmark analysis of immunotherapy duration and disease-free survival in advanced melanoma patients with a complete response. J Clin Oncol. 2020;38(15_suppl). Abstract 10054.