Receives Celgene Payment, Completes Production for Clinical Trials of Internally-Developed ADC

SOUTH SAN FRANCISCO, Oct. 11, 2017 — Sutro Biopharma has received a manufacturing milestone payment from Celgene and has completed production of STRO-001, its first internally-developed antibody drug conjugate, or ADC, using Sutro’s proprietary cell-free protein synthesis technology.  STRO-001 has been manufactured for the planned first quarter 2018 initiation of clinical trials for the treatment of multiple myeloma and aggressive and indolent lymphomas.

This is the second manufacturing milestone achieved by Sutro under its collaboration with Celgene that was established in 2014.

Sutro achieved the milestone as a result of its successful scale-up to 1,000-liter cGMP production of XpressCF+^TM, a proprietary cell-free protein synthesis technology, at Sutro’s cGMP manufacturing center in San Carlos, California – the world’s only such facility.

With this capability now established, Sutro has produced an antibody incorporating a  proprietary non-natural amino acid that allows for site-specific conjugation with a linker and warhead, enabling consistent, stable, pinpoint placement of STRO-001’s toxic payload.  By contrast, many earlier, first-generation ADCs have toxic warheads attached at varying positions, resulting in products with unpredictable and sub-optimal pharmacologic properties, stability and efficacy.

These latest manufacturing achievements are in line with Sutro’s goal of developing its own proprietary product candidates, while simultaneously advancing drug discovery and development in collaboration with Celgene and other partners.

In August, Sutro announced that it was refocusing the 2014 immuno-oncology collaboration with Celgene on four programs advancing through preclinical development, including an ADC  targeting B-Cell maturation antigen, or BCMA, previously disclosed by Celgene.1

The agreement with Celgene provides for the possibility that Sutro will receive additional payments from Celgene for development and regulatory milestones and royalties upon successful commercialization of a product candidate.

“These manufacturing accomplishments mark a big step forward in using cell-free protein synthesis technology at scale as a proprietary production technology for developing multiple best-in-class ADCs and bispecific antibodies,” Sutro CEO Bill Newell said.

About Sutro Biopharma

Sutro Biopharma, located in South San Francisco, has pioneered a compelling and unique way of discovering, developing and manufacturing therapeutics.  Sutro’s focus is primarily next generation cancer therapeutics — antibody drug conjugates, or ADCs, and bispecific antibodies.

Unconstrained by traditional methods of cell-based discovery, Sutro can design and develop targeted medicines by innovating outside the constraints of the cell.

Sutro’s technology enables Sutro to iteratively discover and test molecules in a rapid cycle of weeks rather than months to rapidly identify the optimal molecule designed for safety and potency.

Sutro’s approach to discovery, without the cell, is also transcending the limitations of biologics manufacturing. Sutro has the world’s only cGMP cell-free manufacturing facility located in San Carlos, California. This state-of- the-art facility confers an important competitive advantage as Sutro heads into human clinical trials in 2018.  In addition to developing its own oncology pipeline, Sutro Biopharma is collaborating with select pharmaceutical and biotech companies to discover and develop novel, next generation therapeutics.  As the pace of clinical development accelerates, Sutro and its partners are demonstrating a more efficient approach to killing tumors without harming healthy cells.

Follow Sutro on Twitter, @Sutrobio, and at www.sutrobio.com to learn more about our passion for changing the future of oncology.

Media Contacts

David Schull
Russo Partners
(212) 845-4271
david.schull@russopartnersllc.com

Amiad Finkelthal
Russo Partners
(646) 942-5626
(917) 217-1838 mobile
amiad.finkelthal@russopartnersllc.com