Besides praying to the Father in Jesus' name that He will touch your brother's heart and turn his perspective of life around, you might appeal to his love for you. At a tender moment when you two are together, express your love for him, what he means to you, that his agony is self-inflicted because of his misguided perspective and goal in life, and the secret to being at peace with yourself and the world is to love and be loved. Even though he might not believe , ask him to be with you when you pray to the Father, thanking Him for providing a means for finding peace in your life and that your brother find the peace of not living to elevate or glorify himself and the peace that comes from putting your trust in the Father's plan for our redemption through repentance for past mistakes, trust in Jesus' death for the forgiveness of sins, and the perfecting work of the Holy Spirit who fills our hearts with love. We please God when all our actions and thoughts are motivated by Love.
This might sound corny, get him to agree with you to divulge to each other at least one act or thought motivated by love on a regular basis and increase the list so that eventually he will realize the satisfaction that comes from giving and loving.
Just my thoughts.