About 3000 people had already accessed hepatitis C treatments Harvoni and Viekira Pak since Pharmac began funding them in 2016.
Maviret provided an option for those people who weren't able to access a funded treatment previously due to their genotype of hepatitis C, Williams said.
An estimated 50,000 people could benefit from the treatment, which would be available from February 1, 2019.
Otago University senior lecturer and consultant haematologist Dr Mark Smith said there were about 800 Kiwis living with haemophilia, and about 365 had the severe form haemophilia A, which put them at extreme risk of spontaneous internal bleeding.
Haemophilia could have a significant impact on the quality of life for those living with the condition as well as their families.
"The bleeding will often pool around the joints which can cause significant levels of pain - in the past this was often treated with morphine which severely impacted the ability to function and led to time off work or school," Dr Smith said.
"Haemophilia is often picked up at birth, the baby may be born with unusually severe bruising and then tested as a result."
The approval of the medicine Hemlibra for treating haemophilia was significant as it was the first new treatment for those living with this disease who showed an immunological rejection of factor VIII to be made available in New Zealand in the past 20 years.