Exhibit 99.1 Monte Rosa Therapeutics Announces First Quarter 2026 Financial Results and Business Updates Presented positive interim Phase 1/2 clinical data of GSPT1-directed MGD MRT-2359 in combination with an AR inhibitor in mCRPC patients with AR mutations; initiation of Phase 2 study evaluating MRT-2359 in combination with apalutamide in mCRPC patients with AR mutations planned for Q3 2026 Interim clinical data from GFORCE-1 trial of NEK7-directed MGD MRT-8102 demonstrated profound CRP reductions in subj ...