"Our appeal was rejected," defense lawyer Khin Maung Zaw said in an interview for AFP. "They upheld the ruling of the lower court."
Two Reuters journalists, Wa Lone and Kyaw Soe Oo were arrested in December 2017 and accused of breaking Official Secrets Act for reporting on Rohingya crisis, The Guardian report says.
Earlier this year, the journalists have lost another appeal at the Yangon court, report says. Back in September, the two have been sentenced to seven years in prison.
The two have already been in jail for 16 months.
US Vice President Mike Pence has called on Myanamar leader and Nobel laureate Aung San Suu Kyi to intervene. However, she refused, arguing that the case has "nothing to do with freedom of expression."