When I was hit by painful neuropathy in 2002, after two years suffering, I took a daily dose of Piroxicam (half tablet a day) during 2 years, and my pain gradually disappeared.
You cannot tell if I got some benefits from the anti-inflammatory or some immune modulation properties of the drug.
At that time, I was not aware my disease was related to some auto-immune process, but now that I have thyroid auto-immunity, high adrenergic and muscarinic antibodies and suspected Small fiber Neuropathy, it is likely that all my symptoms could be auto-immune from the beginning (30 years ago).
The problem with these drugs are the kidney and stomach toxicities.