As pointed out the ethical considerations are more worrying than any planet of the apes style situation.
A few other points that have been raised:
1 On human experimentation, that is currently the final phase of testing to get a drug to market, after several levels of animal experimentation, themselves after tests in more limited contexts. The number of humans required to remove all animals from testing is truely insane. Other options like creating full human systems in a lab is morally appaling at best, and part sustems in many ways worse than imperfct anumals as a test inviroment.
2. On humans being inhrantly moer violent and cruel etc than other animals, this is total bullshit, we are mealry in a postion where we can actually afford to be. Most carnivores kill only what they eat, becasue their hunting is inefficient enough that they can't afford to kill any more. When they fight its generally for the same sort of reasons humans do, territory, personal privilage, resources and survival. Make a fox hunt wild animals and it kills sparingly killing what it needs, give it a captive prey source, and it kills more than it needs, and takes only what it does.
What sets humans apart from animals is not mearly sentience but an advanced form of it, and the development of morals, the little basis on saying humans are good or bad is not the actions per say but the fact we have the capscity and morals to define such things, a fox that kills indiscriminately is being instinctive, it knows no better, a human who is not mentally ill is making a choice, and does know better.
Note violence towards other species and you own is not exsclusive to carnivores and true omnivores, herbivores also display it, particuarly when it comes to territrial matters. Humans are mearly the species that got to a point where we could exercise such tendancies on a larger scale first, and no species has made it since that wasnt in close enough competiton to early humans to be wiped out.