It is a traditional custom, especially among many Filipino Catholics, to replace the "Glory Be" prayer during Holy Week with a more somber prayer.
The"Glory Be" prayer is usually said after praying each decade of the Rosary. This has been the custom for many centuries and is the most common way to pray the Rosary.
However, during Holy Week, and in some places starting from the 5th Sunday of Lent, the following prayer will be prayed in its place. The prayer highlights the Passion and death of Jesus and is meant to help Catholics meditate more on the suffering of Jesus.
V. Christ became obedient for us unto death.
R. Even to death on a cross.
These two verses are straight from St. Paul's letter to the Philippians, "he humbled himself, becoming obedient to death, even death on a cross" (Philippians 2:8).
This tradition is popular in the Philippines, and among Filipino Catholics spread throughout the world.
While not a mandatory custom, it reflects the somber mood of Holy Week and is in line with similar practices in the Church, such as omitting the Gloria or Alleluia during Lent.
For those looking for a new way to enter into Jesus' Passion, try replacing the Glory Be with this prayer this year.