Over recent years Pentoxifylline (aka Pentox, Trental) has emerged as a treatment for peyronie's disease. Where some other treatments have come and gone, pentoxifylline does at least appear to be helpful to some men, and has been useful in various other conditions where fibrosis is an component. There have not been many peyronie's specific pentoxifylline studies carried out as yet (aside from this case study), but results in animal studies caused a decrease in PD plaque and collagen/fibloflast ratio, so there is logic to choosing this as a treatment option.
Trental is usually taken in three daily 400mg doses, each seperated by 8 hours. The treatment is typically combined with l-arginine and sometimes viagra. This approach is used by the likes of Dr Levine and Dr Lue, both of whom are respected in urologists. Dr Lue noted that "We have noted regression of calcified chronic plaques in over 50 men treated with 6 months of pentoxifylline". Pentoxifylline downregulates collagen expression, reduces proinflammatory and increases antiinflammatory response so I'm of the believe that for those with peyronie's, the earlier you start taking it the better. Pentoxifylline is oftens used alongside L-Arginine and Viagra as part of the PAV cocktail.
Further information including a .pdf file of the recent pentoxifylline study here.