Digging down to the PLoS One article behind the research, I uncovered the drug's structure and proposed mode of action. Now, where have I seen a compound like that before? Oh, right! Ingenol. Both compounds belong to the phorbol ester family, and both appear to activate protein kinase C, spurring tissue necrosis and tumor shrinkage when directly injected into mouse skin cancer lesions.
The authors indicate that they're preparing GMP product for Phase I human trials; whether that's derived from magical rainforest berries - or just plain process chemistry - hasn't been disclosed.
*The published structure doesn't match the molecular weight (562.25 g/mol) the PLoS authors suggest, and no stereochemistry is specified. I'm guessing it's structurally similar to phorbol, and I've gently highlighted in red a hydrogen that's probably supposed to be a methyl group.