UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ý QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from _______ to _______ Commission File Number: 001-37798 Selecta Biosciences, Inc. (Exact name of registrant as specified in its charter) Delaware 26-1622110 (I.R.S. Employer ...

Selecta Biosciences, Inc. (SELB) Q2 2022 Earnings Conference Call August 4, 2022 8:30 AM ET Company Participants Kevin Tan – Chief Financial Officer Carsten Brunn – President and Chief Executive Officer Peter Traber – Chief Medical Officer Kei Kishimoto – Chief Scientific Officer Conference Call Participants Kristen Kluska – Cantor Fitzgerald Yun Zhong – BTIG Yatin Suneja – Guggenheim Partners John Newman – Canaccord Raju Prasad – William Blair Boobalan Pachaiyappan – H.C. Wainwright Operator Good day, and ...

| --- | --- | --- | |-------|-------|--------------------------------------------| | | | | | | | | | | | | | | | | | | | Selecta Biosciences Corporate Presentation | May 2022 Safe harbor / disclaimer Any statements in this presentation about the future expectations, plans and prospects of Selecta Biosciences, Inc. (the "Company"), including without limitation, statements regarding the Company's cash runway, the unique proprietary technology platform of the Company, and the unique proprietary platform of its ...

Selecta Biosciences, Inc. (SELB) Q1 2021 Earnings Conference Call May 5, 2022 8:30 AM ET Company Participants Carsten Brunn - President & Chief Executive Officer Kevin Tan - Chief Financial Officer Peter Traber - Chief Medical Officer Kei Kishimoto - Chief Scientific Officer Conference Call Participants John Newman - Canaccord Kristen Kluska - Cantor Fitzgerald Yun Zhong - BTIG Raju Prasad - William Blair Uy Ear - Mizuho Boobalan Pachaiyappan - HC Wainwright Chang Liu - Needham Operator 00:05 Good morning a ...

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-Q ý QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from _______ to _______ Commission File Number: 001-37798 Selecta Biosciences, Inc. (Exact name of registrant as specified in its charter) Delaware 26-1622110 (I.R.S. Employe ...

Company Overview - Selecta Biosciences' ImmTOR platform has broad applicability in biologics and gene therapy, with a diversified pipeline expanding to autoimmune diseases and targeted partnerships to maximize platform potential[6] - The company's precision immune tolerance platform aims to restore self-tolerance in autoimmune disease and overcome immunogenicity of gene therapies and biologics[6] - Selecta Biosciences has funding into mid-2024 to support development across pipeline programs[6, 144] ImmTOR Platform & Technology - ImmTOR combines nanoparticle technology with an FDA-approved anti-inflammatory and immunomodulatory drug to generate antigen-specific immune tolerance[9] - Preclinical data indicates a potentially profound synergy of ImmTOR and engineered Treg-selective IL-2 (ImmTOR-IL) to expand antigen-specific Tregs and improve durability of immune tolerance[6] - ImmTOR, by inhibiting the formation of neutralizing antibodies, could make redosing of gene therapies possible[58] Clinical Programs & Pipeline - SEL-212 in chronic refractory gout has dosed over 400 patients, with Phase 3 DISSOLVE I expected readout in Q4 2022[6] - SEL-302: IND for gene therapy program in methylmalonic acidemia (MMA) was submitted in Q3 2021, with Phase 1 start expected in 2H 2022[6, 88] - In a Phase 2 trial, 66% of patients treated with SEL-212 (pegadricase + ImmTOR) maintained control of serum uric acid (SUA), compared to only 15% treated with pegadricase alone[112, 115] - In a study with healthy volunteers, 100% of subjects dosed with 0.3 mg/kg ImmTOR had NAb titers ≤1:25 at Day 30[77]

Financial Data and Key Metrics Changes - As of December 31, 2021, the company had $129.4 million in liquidity, down from $140.1 million a year earlier [29] - Net cash used for the fiscal year 2021 was $60.4 million, compared to a net cash provided by operating activities of $34.9 million in 2020 [30] - Collaboration and license revenue for Q4 2021 was $29.9 million, and for the full year, it was $85.1 million, significantly up from $12 million and $16.6 million in 2020 [31] - The company reported a net income of $12.2 million for Q4 2021, compared to a net loss of $15.4 million in Q4 2020, while the full-year net loss was $25.7 million, down from $68.9 million in 2020 [37][38] Business Line Data and Key Metrics Changes - Research and development expenses for Q4 2021 were $20.3 million, up from $15.1 million in Q4 2020, and for the full year, they were $68.7 million compared to $54.5 million in 2020 [32] - General and administrative expenses for Q4 2021 were $5.5 million, compared to $4.8 million in Q4 2020, with full-year expenses at $20.9 million versus $18.9 million in 2020 [33] Market Data and Key Metrics Changes - The company is focusing on the gene therapy market, particularly with the upcoming Phase 1 trial of SEL-302 for Methylmalonic acidemia (MMA), expected to start in the second half of 2022 [7][22] - The collaboration with Takeda aims to combine ImmTOR with targeted gene therapies for lysosomal storage disorders, indicating a strategic move into rare disease markets [16] Company Strategy and Development Direction - The company aims to advance its precision immune tolerance platform, particularly through the development of ImmTOR-IL, which combines ImmTOR with a Treg-selective IL-2 molecule [9][41] - The focus for 2022 includes accelerating the development of ImmTOR-IL and continuing IND enabling studies for the primary biliary cholangitis program [14] - The company is also exploring partnerships to enhance its gene therapy capabilities, particularly in addressing immunogenicity issues [18] Management's Comments on Operating Environment and Future Outlook - Management expressed confidence in the broad applicability of the ImmTOR platform to restore self-tolerance in autoimmune diseases and mitigate immunogenicity in gene therapies and biologics [40] - The company anticipates multiple catalysts in 2022, including updates on gene therapy opportunities and the completion of the DISSOLVE Phase 3 trial for SEL-212 [42] Other Important Information - The company has taken proactive measures to address the impact of the geopolitical situation in Ukraine and Russia on its clinical trials, including temporarily closing sites in those regions [26][75] - The company is working closely with regulatory authorities to ensure the safety of patients and investigators amid the ongoing conflict [26] Q&A Session Summary Question: Can you discuss the CMC-related items for the hold and future studies? - Management indicated that the FDA had questions regarding the AAV capsid and additional analytics, which were addressed before starting the trial, providing a clearer regulatory path [47][48] Question: How will the FDA's draft guidance on immunogenicity impact physician behavior? - Management noted that their platform specifically addresses anti-drug antibodies (ADAs), which could foster more interest in their technology as it helps overcome challenges faced by many biologics [50] Question: What are the details of the SEL-302 study design for MMA? - The trial will involve administering MMA-101 with three doses of ImmTOR, with provisions for dose escalation based on antibody production [60][63] Question: How will the DISSOLVE II trial be affected by the conflict in Ukraine? - Management confirmed that DISSOLVE I has completed enrollment and is unaffected, while DISSOLVE II has faced disruptions, leading to the addition of U.S. sites to offset enrollment challenges [75] Question: Is there a plan for re-dosing in the SEL-302 trial? - The protocol does not currently include provisions for re-dosing within the first three months, but the FDA is open to discussions based on trial results [100]

UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 (Exact name of registrant as specified in its charter) Delaware 26-1622110 (State or other jurisdiction of incorporation or organization) (I.R.S. Employer Identification No.) 65 Grove Street, Watertown, MA ...

Selecta Biosciences Corporate Presentation SELB January 2022 Safe harbor / disclaimer Any statements in this presentation about the future expectations, plans and prospects of Selecta Biosciences, Inc. ("the company"), including without limitation, statements regarding the progress of the clinical development of SEL-212, the anticipated timing of the head-to-head trial comparing SEL-212 and pegloticase and related data readouts, the potential of ImmTOR™ to reduce AAV vector immunogenicity and enable redosin ...

Selecta Biosciences, Inc. (SELB) Q3 2021 Earnings Conference Call November 9, 2021 8:30 AM ET Company Participants Kevin Tan - Chief Financial Officer Carsten Brunn - President and CEO Peter Traber - Chief Medical Officer Kei Kishimoto - Chief Scientific Officer Conference Call Participants Kristen Kluska - Cantor Fitzgerald Raju Prasad - William Blair Gil Blum - Needham & Company Shu Zhiqiang - BTIG Operator Good morning. And welcome to the Selecta Biosciences Third Quarter 2021 Financial Results and Corpo ...