I agree, I always thought that the idea that "big pharma" would be actively suppressing miracle cure for long term profit is rather improbable.

There's the reason to point out (why pass the opportunity of a huge short term profit?) but also for these types of diseases there's bound to be a high ranking officer within the company who either directly suffers from the illness or has a close family member who does. I doubt that they'd let themselves or their wives die for the sake of getting a nice +3% to benefits ten years down the line.