How effective is ivacaftor?

Could you elaborate on the effectiveness of ivacaftor? Are there any specific conditions or patient populations where it has shown particularly favorable results? Additionally, what are some potential limitations or drawbacks to using ivacaftor? Is there any research suggesting long-term benefits or potential risks associated with its use? Furthermore, how does ivacaftor compare to other available treatments for similar conditions, and what factors should be considered when deciding whether to prescribe it?