Con to the question "Should Animals Be Used for Scientific or Commercial Testing?"
"Not only are animals poor models of safety for humans, but they are also unreliable for demonstrating the effectiveness of treatments too. Just as many drugs fail in clinical trials because they turn out to cause side-effects in humans, many others turn out to be ineffective in humans, despite performing well in animals. This makes drug development extraordinarily expensive because companies need to recoup the costs of clinical trials not only for successful drugs, but also for the nine others that fail for each one that succeeds...
[F]ar from jeopardizing progress, a shift to advanced techniques based on human biology would accelerate biomedical research, and deliver safer and better medicines at lower costs: a win–win situation that should be supported by everyone."
"Of Mice but Not Men," What Doctors Don't Tell You, Aug. 2016