While the relatively recently approved treatment options for melanoma (both targeted and immunotherapy) have been absolutely life saving for many, myself included, there are still far too many of us in need of something else!!! To that end, here is a case study...
To begin, PEG is polyethylene glycol, a vehicle used to make things soluble in water (or the human body) so that a drug/substance can be administered. It is use in PEG-interferon, for example. Arginase is an enzyme that breaks down arginine. Arginine is an essential amino acid needed for protein synthesis. It is used in the liver, for example, to help excrete ammonia. Strangely, some melanoma cells are unable to synthesize their own arginine, making them dependent on arginine from other cells. So now...there is this:
Metabolic therapy with PEG-arginase induces a sustained complete remission in immunotherapy-resistant melanoma. De Santo, Cheng, Beggs, et al. J Hematol Oncol. 2018 May 18.
For what it's worth! - c