A compound of formula I
or a pharmaceutically acceptable salt thereof in which R
1
, R
2
, R
3
, R
4
and m are as described in the specification for use in the treatment of obesity and/or diabetes.
A compound of formula I
or a pharmaceutically acceptable salt thereof in which R
1
, R
2
, R
3
, R
4
and m are as described in the specification for use in the treatment of obesity and/or diabetes.