I would suggest having this checked for alignment, or set about checking toe-in yourself (really only needs a tape-measure and some time).
What I think I'm seeing:
1) the one-edge-wear indicates camber. Your tire isn't sitting vertical. It's OK for this to be the case, and even beneficial, but perhaps not necessary in a trailer, and your wear indicates perhaps too much. By itself, camber isn't considered much of a "wear" setting; it's not the root cause of your treadwear but rather it's part of the whole story
2) toe. too much toe-(in, or out) will cause wear. In this case, it looks like it's causing wear only at the contact-patch allowed by the camber. Toe can be measured with a tape-measure if you're so-inclined. I have no idea what appropriate angles might be for a trailer (more familliar with my various trucks and SUVs).
Taken alltogether, I might offer:
-don't simply replace the tire. you have underlying issues that will affect a replacement.
-both toe and camber *could* be affected by loose/worn/busted bearings. Don't overlook this first, realatively easy step.
-I don't think the Torflex axle is really meant to be adjusted; it would probably require a frame-shop with hydraulics and tie-downs to "persuade" it into alignment.
-I wonder if you may have hit a major pot-hole along the way, to cause bending?
Ultimately, I think you should check bearings, then somehow have the alignment checked.
Hope this helps you sort it out,