This study is being conducted to test the safety and efficacy of ramucirumab in combination with other chemotherapy in the treatment of relapsed, recurrent, or refractory desmoplastic small round cell tumor (DSRCT) in children and young adults. This trial is part of the CAMPFIRE master protocol (NCT05999994) which is a platform to accelerate the development of new treatments for pediatric and young adult participants with cancer. Your participation in this trial could last 12 months or longer, depending on how you and your tumor respond.