 TRACON Pharmaceuticals Inc NASDAQ:TCON said it has dosed the first patient in a Phase 12 trial evaluating the companys CTLA-4 antibody, YH001, in combination with its PD-L1 antibody envafolimab and with doxorubicin, in front line therapy of patients with malignant tumours. The Phase 12 trial will assess the safety and efficacy of the triplet combination of YH001, envafolimab and doxorubicin in the common sarcoma sub-types of leiomyosarcoma and dedifferentiated liposarcoma, according to TRACON. 