Sutro Biopharma, Inc. is a publicly traded biotechnology company headquartered in South San Francisco, California focused on clinical-stage drug discovery, development and manufacturing.

As of 2024[update] Sutro's drug discovery efforts have focused on antibody-drug conjugates, cytokine-based immuno-oncology therapies, and bispecific antibodies primarily directed at clinically-validated targets for which the current standard of care is suboptimal.

Sutro's Xpress CF Platform[2] is based on Stanford Professor James R. Swartz's patented Open Cell-Free Synthesis (OCFS) technology.

[3] The XpressCF+ platform allows for precise incorporation of non-natural amino acids into a protein sequence, and Sutro is using this technology to develop homogeneous site-specific antibody-drug conjugates (ADCs).

[4] Once identified, production of protein drug candidates can be scaled in Sutro's cGMP manufacturing facility located in San Carlos, CA.