HD-IL2, is FDA approved since 1992, is a taxing therapy delivered best in specialized centers of excellence as inpatient intravenous therapy (5 days in hospital, 9 days recovery at home, 5 days in hospital) which was shown to cure 5-8% of patients and help stabilize or shrink disease in additional 20-25% (usually for 7-24 months).
PD-1 therapies are very recent, but with exciting potential to be delivered on outpatient basis, in a vein, every 2-3 weeks and with objective substantial shrinkage in 20-50% of patients. Long term results from Dr. Sznol reported at ASCO 2013 suggest durability of these responses for 24 months. However, it is not yet clear if the long term cures will be observed at the same (or better/worse) rate than with IL-2.
Currently, I encourage patients to enroll on PD1 or PDL1 trials when available as HD IL-2 can be given as standard of care after that therapy. Some patients unfortunately will not be healthy enough to get IL-2 after PD1. If that is a major concern, HD IL-2 can be given first. However, some PD 1 trials will not allow prior HD IL-2 or may close by the time progression after IL-2 develops.
It is a decision best made with your treating physician.
