Depends on how you look at it I suppose.

If one thinks that unique human beings are more important than lab rats that are farmed to be experimented on then it is perfectly moral.

Put another way, if someone in your family had 3rd degree burns to their face and whole upper body and needed new skin. Would you sacrifice a few lab rats to save your family member's life and let them lead a normal life again?

Or would you say, sorry we could have helped you but we couldn't bear to hurt the poor rats to find the solution to your problem?

(and we can replace skin with hearts, liver, kidney, lungs, eyes and any other organ that might be able to be replaced in the future)