MDX-020-010 trial

Background

Phase III RCT of 676 patients with previously treated unresectable stage III or IV melanoma, randomized 3:1:1. First trial to demonstrate an OS benefit for any agent in metastatic melanoma.

Interventions and follow up

Arm A: Ipilimumab 3mg/kg IV q3wk x4 + gp100 peptide vaccine
Arm B: Ipilimumab 3mg/kg alone
Arm C: gp100 vaccine alone
Primary endpoint: overall survival
Median follow-up: ~17-27mo

Results

mOS (ipi3+gp100 vs gp100): 10.0mo vs 6.4mo; HR 0.68, P<.001
mOS (ipi3 alone vs gp100): 10.1mo; HR 0.66, P=.003
Durable benefit: a subset of patients achieved long-term survival, establishing the immunotherapy tail-of-the-curve phenomenon

Adverse events

Grade 3-4 irAEs: 10-15% in ipilimumab-containing arms vs 3% with gp100 alone
irAE-related deaths: 7 of 14 treatment-related deaths were associated with immune-related events; most common irAEs were dermatologic and gastrointestinal (diarrhea/colitis)

Conclusions

Ipilimumab was the first therapy to improve overall survival in metastatic melanoma, ushering in the checkpoint-inhibitor era. With OS comparable to high-dose IL-2 but no requirement for ICU-level care, ipilimumab 3mg/kg became a standard of care.

Key Limitations

Pretreated population only; modest absolute OS gain; gp100 control arm not a contemporary standard; significant immune toxicity including treatment-related deaths. Anti-PD-1-based regimens have since surpassed ipilimumab monotherapy.

Clinical Context

Led to FDA (2011) and EMA approval of ipilimumab for unresectable/metastatic melanoma, the first checkpoint inhibitor approved in oncology. Subsequent dose comparison (ipi3 vs ipi10, PMID:32503946) showed ipi10 numerically better OS (15.7 vs 11.5mo, HR 0.84) but higher toxicity, so ipi3 remained standard. ESMO endorses checkpoint inhibition for advanced melanoma.

References