Can a popular class of diabetes drugs that includes Merck's Januvia help treat COVID-19?

Can a popular class of diabetes drugs that includes Merck's Januvia help treat COVID-19?

Source: 
Fierce Biotech
snippet: 

As COVID-19 spread across the globe, scientists are hunting for drugs that could be repurposed as a quick way to tackle the disease. Among them is a University of Miami researcher who has pointed to previous studies of other coronaviruses to back up his suggestion that a class of diabetes medications known as DPP-4 inhibitors might help.