Recently, Sutro Biopharma announced that the US Food and Drug Administration (FDA) has granted STRO-001 the orphan drug qualification for the treatment of multiple myeloma (MM). STRO-001 is a potential first antibody drug conjugate (ADC) that targets CD47, a protein highly expressed in B cell malignancies such as MM.

Orphan drugs are used to prevent, treat, and diagnose rare diseases, a general term for diseases with extremely low incidence, also known as “orphan disease.” In the United States, a rare disease is a condition that affects fewer than 200,000 patients. Pharmaceutical companies developing orphan drugs will receive incentives, including various clinical development incentives such as tax credits related to clinical trial costs, FDA user fee reductions, FDA assistance in clinical trial design, and a seven-year market exclusivity period after drug approvals.

Introduction of STRO-001

STRO-001 was developed by Sutro using cell-free protein synthesis and site-specific conjugation techniques with precise antibody design and rapid empirical optimization. STRO-001 is designed to directly target cancer cells and deliver cytotoxic agents, currently in Phase I clinical development for the treatment of myeloma and B-cell lymphoma.

Dr. Trevor Hallam, Sutro’s Chief Scientific Officer, once said: “With the XpressCF+ platform, we specifically locate unnatural amino acids in antibodies for the binding of cytotoxin conjugates at specific sites, thus ensuring the consistency, stability and precise positioning of STRO-001 toxicity load and enabling efficient delivery of cytotoxins to tumor cells. In contrast, early ADCs may have unpredictable pharmacological properties, leading to potential metastability, impaired efficacy and poor patient tolerance.”

To date, Sutro has designed cytokine-based immuno-oncology therapies, antibody drug conjugates, and bispecific antibodies for targets that have been clinically validated but are not ideal for current standard drug treatments.

In addition to its oncology pipeline development, Sutro has partnered with several pharmaceutical and biotechnology companies, including Merck, Merck Serono, and New Base, to discover and develop next-generation therapeutics to more effectively kill the tumor without harming healthy cells.