I'm not sure the margins support that allegation. Sovaldi is manufactured by Gilead (which also makes a Harvoni generic). They don't break out drug-specific margin, but http://truecostofhealthcare.org/wp-content/uploads/2014/12/G... and https://www.investors.com/news/technology/can-gilead-withsta... have some food for thought.
A couple things stand out:
1. Their profit margin varies year to year, but in the peak period from 2012-2019 it was 35-55%, averaging ~40-45%. While that's industry-leading for pharma, it's nowhere near high enough to say that their products could be, say, 75% (or even 50%) cheaper. A 20% reduction (very roughly cutting margins in half) wouldn't make it meaningfully more affordable and I don't think most people would describe that as gouging.
2. Apparently it actually cures the disease for many people, so this is a once-and-done treatment. Compared to nearly all other healthcare interventions, curing a life-threating chronic degenerative condition at this price is cheap. (Cost per death prevented of other interventions: https://journalofscientificinnovationinmedicine.org/articles..., https://twitter.com/troyd/status/1195811217056485377)
3. After they cured so many people, there was a much smaller market (success!). Revenue and margin both dropped a lot: https://www.macrotrends.net/stocks/charts/GILD/gilead-scienc...
4. "Gilead Sciences was also unique in that it was the only pharmaceutical company I examined that spent less money on marketing than they spent on research. Gilead’s marketing budget was only 15% of their total revenue."
This seems like a pretty clear example of why looking at revenue and margin like this is not a good way to manage this. Our goal here is clearly to eliminate the market for this product, and everyone ought to chip in to make that happen, not just the people who currently are at risk. The whole funding model is fundamentally broken.
That's a totally reasonable point (and perhaps worth starting a separate top-level reply about), but it's not at all what the GP comment was arguing.
(I'm not sure whether the evidence justifies that claim either, but the claim is a lot stronger than gouging)
Is Google/Apple/MS/FB price gouging? Their net incomes are massive.
I'd be hard pressed to classify a situation were a company introduces a new product 80% cheaper than the alternative, and still be guilty of price gouging.
As usual the answer probably lies somewhere in the middle.