– Phase 3 DISSOLVE I and DISSOLVE II studies both met their primary efficacy endpoints, with SEL-212-treated patients demonstrating statistically significant higher response rates compared to placebo –

– SEL-212 was observed to have a favorable safety profile and was well-tolerated across both doses of ImmTOR –

– BLA filing expected in 1H 2024 –

WATERTOWN, MA, USA I May 31, 2023 I Selecta Biosciences, Inc. (NASDAQ: SELB), a biotechnology company leveraging its clinically validated ImmTOR™ platform to develop tolerogenic therapies for autoimmune diseases and gene therapies, today announced the presentation of positive data from the Phase 3 DISSOLVE I and DISSOLVE II double-blind, placebo-controlled studies of SEL-212 in patients with chronic refractory gout. SEL-212 is a combination of Selecta’s ImmTOR immune tolerance platform and a therapeutic uricase enzyme (pegadricase). The data were featured during a late-breaking oral presentation at the European Alliance of Associations for Rheumatology (EULAR) 2023 European Congress of Rheumatology being held May 31 – June 3 in Milan, Italy.

“Marked by chronic pain and significant functional impairment, chronic refractory gout carries a large disease burden, with currently available therapies falling short and patients experiencing an impaired and poor quality of life,” stated the study’s lead author and Principal Investigator of the DISSOLVE Program, Herbert S.B. Baraf, M.D., FACP, MACR, founding Medical Director of The Center for Rheumatology and Bone Research, and Clinical Professor of Medicine at George Washington University in Washington, DC. “We believe SEL-212 has demonstrated strong potential to serve as a safe and effective uricase-based intervention for patients suffering from this debilitating disease without the need for separate oral traditional immunosuppressants and with the convenience of once-monthly dosing.”

“The efficacy and safety profile observed across the Phase 3 DISSOLVE program underscores our belief that the ImmTOR platform, which, to our knowledge, represents the only immune tolerance platform with positive Phase 3 data, has the potential to deliver meaningful tolerogenic therapies. We look forward to continuing to work with our partner, Sobi®, to file a Biologic License Application (BLA) for SEL-212 in the first half of next year,” said Carsten Brunn, Ph.D., President and Chief Executive Officer of Selecta.


DISSOLVE I (US Study) & DISSOLVE II (Global Study) were Phase 3, double-blind, placebo-controlled studies of SEL-212 evaluated at two doses of ImmTOR™ (0.1 mg/kg and 0.15 mg/kg) and one dose of pegadricase (0.2 mg/kg). In March 2023, the Company announced topline data from both studies. Data featured at EULAR 2023 Congress are summarized below.

  • Both Phase 3 studies and both once-monthly SEL-212 doses tested met primary efficacy endpoints, achieving a statistically significant response rate, defined as the percentage of patients who achieved and maintained a serum urate (SU) < 6 mg/dL for at least 80% of the sixth 28-day treatment period, and reductions in SU compared to placebo.
    • The response rate in the high dose group was 56% in DISSOLVE I and 46% in DISSOLVE II.
  • The response rate in the high dose group for patients ≥50 years old was 65% and 47% in the DISSOLVE I & II studies, respectively.
  • For the secondary endpoint of reduction in SU from baseline, a marked reduction of approximately 60% was observed in both studies for both dose levels.
  • SEL-212 was observed to have a favorable safety profile and well-tolerated across both doses levels.

A copy of the presentation will be available in the Resources section of Selecta’s website, http://www.selectabio.com/.

About the DISSOLVE Clinical Program
The Phase 3 DISSOLVE clinical program consisted of two double-blind, placebo-controlled studies of SEL-212, titled “A Randomized Double-Blind, Placebo-Controlled Study of SEL-212 in Patients with Gout Refractory to Conventional Therapy,” in which SEL-212 was evaluated at two doses of ImmTOR (0.1 mg/kg and 0.15 mg/kg), and one dose of pegadricase (0.2 mg/kg) in both studies. In DISSOLVE I, safety and efficacy were evaluated at six months and with a six-month blinded extension to evaluate safety. DISSOLVE II assessed safety and efficacy at only the six-month time point, with no extension. The primary endpoint in both studies was serum urate (SU) control during month six, a well-validated measure of disease severity in chronic refractory gout. Secondary endpoints include tender and swollen joint counts, tophus burden, patient-reported outcomes of activity limitation and quality of life and gout flare incidence. For more details about the study, visit clinicaltrials.gov (NCT04513366).

About SEL-212
SEL-212 is a novel investigational combination medicine designed to reduce serum urate (SU) levels in people with chronic refractory gout, potentially reducing harmful tissue urate deposits which when left untreated can lead to debilitating gout flares and joint deformity. SEL-212 consists of pegadricase, Selecta’s proprietary pegylated uricase, co-administered with ImmTOR, designed to mitigate the formation of anti-drug antibodies (ADAs). ADAs develop due to unwanted immune responses to biologic medicines, reducing their efficacy and tolerability, which remains an issue across multiple therapeutic modalities and disease states including chronic refractory gout.

About Selecta Biosciences, Inc.
Selecta Biosciences Inc. (NASDAQ: SELB) is a clinical stage biotechnology company leveraging its ImmTOR™ platform to develop tolerogenic therapies that selectively mitigate unwanted immune responses. With a proven ability to induce tolerance to highly immunogenic proteins, ImmTOR has the potential to amplify the efficacy of biologic therapies, including redosing of life-saving gene therapies, as well as restore the body’s natural self-tolerance in autoimmune diseases. Selecta has several proprietary and partnered programs in its pipeline focused on enzyme therapies, gene therapies, and autoimmune diseases. Selecta Biosciences is headquartered in the Greater Boston area. For more information, please visit www.selectabio.com.

SOURCE: Selecta Biosciences