Treatments for rare diseases are not profit generators for Big Pharma, so research is funded in part by patients:

Last May, Lee Hollett received an unsettling letter.

He had been taking an experimental drug as part of a clinical trial for patients with a fatal degenerative disease called amyotrophic lateral sclerosis, or ALS. But the trial’s supply of the drug was running low, the letter warned, and there was no money to buy more.

Could Mr. Hollett send a check?

“I’ve kind of accepted that I have a terminal disease,” says Mr. Hollett, a human-resources executive. “But my wife has high hopes that I’ll live long enough to see a cure.” And though the drug hadn’t stopped the relentless progression of the disease — he is now in a wheelchair — Mr. Hollett believes it has helped him maintain critical lung capacity.