Selecta Biosciences

About

Selecta Biosciences, Inc., founded in 2007 and based in Watertown, Massachusetts, is a clinical-stage biopharmaceutical company developing its proprietary ImmTOR nanoparticle platform to address a critical challenge in biologics therapy—unwanted immune responses that reduce treatment efficacy. Publicly traded on NASDAQ (SELB) with over $300 million in funding and 100-200 employees, Selecta has pioneered synthetic vaccine particles (SVP) that can selectively modulate immune responses, potentially enabling repeat administration of therapeutic proteins and gene therapies. The company emerged from research on how nanoparticle properties influence immune system activation, discovering that specific nanoparticle designs could induce immune tolerance rather than immunogenicity. Selecta's ImmTOR platform consists of biodegradable polymer nanoparticles incorporating immunomodulatory small molecules (typically rapamycin analogs) that are taken up by immune cells, inducing tolerance to co-administered therapeutic agents. This approach addresses a major limitation of protein therapeutics and gene therapies—the development of neutralizing antibodies that reduce or eliminate treatment efficacy with repeated dosing. For example, many patients with gout receiving enzyme replacement therapy develop anti-drug antibodies that neutralize the therapeutic enzyme, requiring treatment discontinuation. Selecta's lead program, SEL-212, combines ImmTOR nanoparticles with pegsiticase enzyme therapy for severe gout, with clinical trials demonstrating reduced immunogenicity and improved sustained therapeutic response. The company has expanded its platform to address immunogenicity challenges in gene therapy, where immune responses against viral vectors or therapeutic proteins can limit treatment durability. Selecta has established partnerships with major pharmaceutical companies including Sarepta Therapeutics and Asklepios BioPharmaceutical to apply ImmTOR technology to gene therapy programs for muscular dystrophies and other genetic diseases. The company's nanoparticles are engineered with precise sizes (typically 200-500 nanometers), controlled drug loading, and surface properties optimized for uptake by specific immune cell populations. Selecta has developed manufacturing processes producing clinical-grade ImmTOR nanoparticles at scales required for therapeutic applications, addressing a key challenge in nanomedicine translation. The company's approach represents sophisticated application of nanotechnology principles—using nanoparticle properties to program specific biological responses rather than simply delivering drugs. Selecta's clinical programs have generated important data on how synthetic nanoparticles can modulate human immune systems, contributing to fundamental understanding of nanoparticle immunology. As gene therapies and protein biologics become increasingly important in medicine, addressing immunogenicity challenges will be crucial for enabling repeat dosing and expanding patient populations. Selecta's ImmTOR platform offers a potentially broadly applicable solution to this critical problem, positioning the company at the intersection of nanomedicine and immunotherapy, two of the most promising areas in biopharmaceutical development.