> Would the same medicine be created (often costing large sums of money) if they didn't have the incentive of profit? What's the alternative that creates the same quality and quantity?

No, in fact they might produce different drugs rather than slightly modifying [0] a very old drug [1] because they can renew the i.p. protections and go back to selling lifesaving drugs to sick people at unaffordable prices.

[0] CellCept

[1] mycophenolate