You are implying that because XYZ has lower profit as a percentage yet higher profit as a nominal dollar amount, that XYZ will charge its American patients more. My intuition says both ABC and XYZ will charge Americans the same, namely the highest amount it possibly can under market/regulatory/PR/competitive considerations.
American scholars write some of the most respected textbooks in the world, they are then sold in US colleges for $100-400/each. The same book is then sold in SE Asia and Africa for $10-40/each.
Activating the immune system is risky. It is strong and it can crush cancer in mere weeks, but it is also very dangerous to friend and foe alike. Basically, you gather a lot of absolutely ruthless and stupid troops and tell them "here is ze Flammenwerfer, burn the enemy to crisp, but don't destroy anything else".
Easier said than done.