If the student remains defiant in demanding that they are exempt from standard expectations, they may benefit from a behaviour contract. This promotes responsibility and accountability. This can also improve communication between home and school to encourage parents to take an active role in ensuring their child's success, including not removing them from school at critical times.
Organisational tools, such as a clear schedule for assignments and exams that is broken into smaller milestones, can also help keep the student on track. Milestones, homework etc. can be signed off by the student, parent, and teacher. This can improve time management and ensure that the student can catch up (and demonstrate that catching up is their own responsibility) should they miss any classes.
In order to ensure that the teacher is providing the most positive reinforcement, the student should take a Forced-Choice Reinforcement Survey. In order to motivate a student who might otherwise feel entitled to special treatment, it is key to find out what is most important to them and what can be used as a positive motivator.