These results set a new standard of care in this patient population, the study’s lead author, Christian U. Blank, MD, PhD, reported at the annual meeting of the American Society of Clinical Oncology in Chicago.
Dr. Blank, a hematologist/oncologist from the Netherlands Cancer Institute in Amsterdam, called the result “very special,” noting that the trial included an active comparator, rather than a placebo control.
“When we treat these patients with surgery only, the outcome … is very bad: The 5-year relapse-free survival is only 30% and the overall survival is only 50%. Adjuvant therapy improves relapse-free survival but not overall survival ...Thus, there is an urgent need for these patients for novel therapy approaches,” he said during a press conference at the meeting.
Study Methods and Results
The study included 423 patients with stage III de novo or recurrent pathologically proven resectable melanoma with at least 1 lymph node metastasis. Patients were randomized to either the experimental neoadjuvant arm (n = 212), or the standard treatment control arm (n = 211), which consisted of therapeutic lymph node dissection (TLND) followed by 12 cycles of adjuvant nivolumab (NIVO 480 mg every 4 weeks).
Patients in the experimental arm received two cycles of neoadjuvant ipilimumab (IPI 80 mg every 3 weeks) plus NIVO 240 mg for 3 weeks followed by TLND. Those with a major pathologic response (MPR), defined as less than 10% vital tumor cells in the post-neoadjuvant resection specimen, went straight to follow-up.
Those without an MPR received adjuvant therapy. For patients with BRAF wild-type, this involved 11 cycles of adjuvant NIVO (480 mg every 4 weeks), while BRAF-mutated patients received dabrafenib plus trametinib (150 mg b.i.d./2 mg once a day; 46 weeks).
The study met its primary endpoint — event-free survival (EFS) — at the first interim analysis. After a median follow-up of 9.9 months, the estimated EFS was 83.7% for neoadjuvant immunotherapy versus 57.2% for standard of care, (P less than .0001, hazard ratio [HR] = 0.32).
“When we look into the subgroups, for example BRAF-mutated status or BRAF-wild-type status ... you see for both groups also a highly statistically significant outcome favoring the neoadjuvant therapy with hazard ratios of 0.29 and 0.35,” said Dr. Blank.
In total, 59% of patients in the experimental arm had an MPR needing no further treatment. “This is important, because the patients that achieve a major pathologic response have excellent outcomes, with an EFS of 95%,” said Dr. Blank.
He added that those with a partial response had an EFS of 76%, and among those who had “nonresponse,” the EFS was 57% — the same as that of patients in the control arm.
Toxicities were considered transient and acceptable, with systemic treatment-related grade 3 or 4 events in 29.7% of the neoadjuvant arm and 14.7% of the adjuvant arm.
NADINA is the first neoadjuvant checkpoint inhibitor phase 3 study in melanoma and the first phase 3 trial in oncology testing a checkpoint inhibitor without chemotherapy, noted Dr. Blank.
“At the moment we see only additions of immunotherapy to the chemotherapy neoadjuvant arms, but here you see that we can also treat patients with pure immunotherapy.”