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Catalyst Biosciences & Mosaic Biosciences Present Preclinical Data on Pegylated CB 2782 for the Treatment of Dry Age-Related Macular Degeneration

April 29, 2019

A single intravitreal injection of 125 μg CB 2782-PEG achieved complete, rapid and sustained pharmacodynamic inhibition (>99%) of complement factor 3 (C3) in non-human primates (NHP), supporting dosing three to four times a year

Data support CB 2782-PEG’s potential as a best-in-class anti-C3 ocular therapy

SOUTH SAN FRANCISCO, Calif. and BOULDER, Colo., April 29, 2019 (GLOBE NEWSWIRE) -- Catalyst Biosciences, Inc. (NASDAQ: CBIO), and Mosaic Biosciences today announced the presentation of new data on pegylated CB 2782 (CB 2782-PEG), Catalyst’s preclinical anti-C3 candidate being developed for the treatment of geographic atrophy (GA) associated dry age-related macular degeneration (dry AMD) at the 2019 Annual Meeting of the Association for Research in Vision and Ophthalmology (ARVO), being held in Vancouver, British Columbia, from April 28 - May 2, 2019.

The poster, entitled: “Pegylated CB 2782: A Complement Factor C3-Inactivating Protease and Potential Long-Acting Treatment for Dry AMD,” was presented by Eric Furfine, Ph.D., Mosaic’s Head of Ophthalmology. The data demonstrate CB 2782-PEG’s potential for a superior efficacy profile and improved convenience over clinical candidates in Phase 3 development. A copy of the presentation materials can be accessed on the Events and Presentations section of the Catalyst website. Key highlights include:

  • Unmodified and PEGylated CB 2782 selectively degrade C3 into inactive fragments
  • PEGylation increased CB 2782’s ocular half-life from 1.7 to 3.7 days without compromising activity
  • A single intravitreal injection of 125 μg CB 2782-PEG demonstrated greater than 99% elimination of C3 from the vitreous humor for at least 28 days
  • NHP PK and PD data predict human intravitreal dosing three or four times a year

“Geographic atrophy, an advanced form of dry AMD, affects over a million people in the United States and can have a devastating impact on vision. Currently there are no approved treatment options for these patients. C3 is the only clinically validated target for GA in dry AMD, therefore CB 2782-PEG’s ability to nearly eliminate C3 with intravitreal dosing three or four times a year has the potential to be a best-in-class therapy,” said Eric Furfine, Ph.D., Head of Ophthalmology at Mosaic.

In 2017 Catalyst and Mosaic entered into a strategic collaboration to develop novel protease-based anti-C3 intravitreal products. Catalyst retains global commercial rights for all collaboration products and Mosaic receives product sublicense fees and/or milestone payments and royalties.

About Catalyst Biosciences
Catalyst is a clinical-stage biopharmaceutical company developing novel medicines to address hematology indications. Catalyst is focused on the field of hemostasis, including the subcutaneous prophylaxis of hemophilia and facilitating surgery in individuals with hemophilia. For more information, please visit

About Mosaic Biosciences
Mosaic Biosciences is private biotechnology company that is advancing a highly versatile and fundamentally new class of biomaterials based on engineered proteins and synthetic polymers.  Mosaic’s technology platform provides the leading biomaterial for cell- and protein-therapeutic delivery, and regenerative medicine.  For more information, please visit

Forward-Looking Statements
This press release contains forward-looking statements that involve substantial risks and uncertainties. Such statements include statements about the potential uses and benefits of CB 2782-PEG to treat geographic atrophy or dry AMD, the potential for CB 2782-PEG to be a best-in-class therapy, and to have human dosing three or four times per year. Actual results or events could differ materially from the plans, intentions, expectations and projections disclosed in the forward-looking statements. Various important factors could cause actual results or events to differ materially from the forward-looking statements that the Company makes, including, but not limited to, the risk that clinical trials and studies may be delayed and may not have satisfactory outcomes, that human trials will not replicate the results from animal studies, that potential adverse effects may arise from the testing or use of CB 2782-PEG, the risk that costs required to develop or manufacture the Company’s products will be higher than anticipated, competition, other factors that affect Catalyst’s ability to establish collaborations on commercially reasonable terms and other risks described in the “Risk Factors” section of the Company’s Annual Report on Form 10-K for the year ended December 31, 2018 filed with the Securities and Exchange Commission on March 8, 2019, and with other filings with the Securities and Exchange Commission. The Company does not assume any obligation to update any forward-looking statements, except as required by law.

Fletcher Payne, CFO
Catalyst Biosciences, Inc.

Josephine Belluardo, Ph.D.
LifeSci Public Relations


Source: Catalyst Biosciences, Inc.