Checkpoint Therapeutics Inc., of New York, and TG Therapeutics Inc., also of New York, said they dosed the first patient in a phase I trial testing anti-PD-L1 monoclonal antibody CK-301 in checkpoint therapy-naïve patients with selected recurrent or metastatic cancers. The trial will measure the safety and tolerability as well as the pharmacokinetics, immunogenicity and preliminary efficacy of the drug. Checkpoint plans to provide clinical updates on the study in the first half of 2018. The two companies have been working together since 2015.