#1Investor Presentation May 2023 R REPLIGEN#2Safe Harbor / Non-GAAP financial measures This presentation contains forward-looking statements within the meaning of the federal securities laws. Statements in this presentation which are not strictly historical statements including, without limitation, express or implied statements or guidance regarding Repligen's estimated financial results for full year 2023, future financial performance and other statements identified by words like "estimated," "anticipated," "guidance," or "goal," and similar expressions are forward-looking statements. These statements are subject to risks and uncertainties which may cause our plans to change or actual results to differ materially from those anticipated. In particular, unforeseen events outside of our control may adversely impact future results. Additional information ing these factors is discussed in ou reports filed with the Securities and Exchange Commission including recent Form 8-Ks, our most recent Annual Report on Form 10K and our most recent Quarterly Reports on Form 10Q, all of which are available on our website. The forward-looking statements in this presentation reflect management's current views and may become obsolete as a result of new information, future events or otherwise. We may not update such forward looking statements to reflect a change of events or circumstances that occur after the date hereof, except as required by law. The industry and market data contained in this presentation are based on management's own estimates, independent publications, government publications, reports by market research firms or other published independent sources, and, in each case, are believed by management to be reasonable estimates. Although we believe these sources are reliable, we have not independently verified the information. This presentation discloses certain financial measures not prepared in accordance with generally accepted accounting principles, or GAAP. Repligen strongly encourages investors to review our consolidated financial statements and publicly filed reports in their entirety and cautions investors that the non-GAAP measures used herein may differ from similar measures used by other companies, even when similar terms are used to identify such measures. R REPLIGEN 2#3Repligen Overview Strong Revenue Growth through Innovation Leadership R REPLIGEN#4We are the innovation leader in bioprocessing Enabling efficient, single-use, high-productivity biological drug manufacturing $802M 2022 Revenue +20% +22% organic Differentiated technologies R REPLIGEN +42% 5-year CAGR +26% 5-year avg. base growth Revenue growth through acquisitions, innovation 8 M&A Deals since YE 2016 Diversified customer base, all biological drug modalities 10 Disruptive technology launches 7% of revenue in 2022 was from products launched 2021-2022 65% Clinical 35% Commercial (excl. COVID) 18 global facilities, 2,000+ employees 2022 figures reflects full-year results as of our Q4 earnings call Feb. 22, 2023. "Base" excludes COVID-related & inorganic M&A revenue. 4#5Strong revenue growth driven by innovation and portfolio expansion Analytics $54M 7% Chroma $36M 26% 2017 $141M Revenue R REPLIGEN Filtration $49M 35% Proteins $54M 38% 2017-2022 34% 5-year avg. annual organic growth Chroma $132M 16% Proteins $114M 14% 2022 $802M Revenue Filtration $496M 62% Long life-cycle, highly differentiated systems and consumable products 2022 total revenue reflects full year results as of our Q4 earnings call Feb. 22, 2023. 2022 franchise-level revenue and percent of total reflect franchise-level growth results as of our Q4 earnings call Feb. 22, 2023. 5#62022e revenue splits (directional) Consumables, biopharma development and mAb applications were the largest contributors CONSUMABLES/EQUIPMENT % of Total Revenue 25% R REPLIGEN 75% Equipment Consumables BIOPHARMA/CDMO/INTEGRATORS % of Total Revenue 17% 4% 29% 49% Biopharma Developers CDMOS Integrators Other 2022e total revenue reflects 2022 financial results as of Feb. 22, 2023. BIOLOGIC TYPE 18% (COVID) 14% (C&GT) $141M TOTAL: $802M $115M 68% (mAbs) $546M 6#7Market Landscape & Addressable Market Healthy End Markets and Expanding TAM R REPLIGEN#8mAbs, Gene Therapy and mRNA fueling our growth Monoclonal Antibodies Cell & Gene Therapy R REPLIGEN ~$150B Market 2021 Growing at >10% annually >$5B Market 2021 Growing at >25% annually >140 U.S. FDA Approvals incl. 26 Biosimilars 15 U.S. FDA Approvals incl. 10 Cell, 5 GT >800 Phase I-III >1,500 Active clinical trials >2,200 Active clinical trials New approvals and growing biosimilars pipeline Emerging opportunities beyond COVID Data sources: $s Company filings/guidance; Approvals: U.S. FDA website; Antibody therapeutics approved or in regulatory review in the EU or US - The Antibody Societ; PHrMA reports; Repligen internal mAbs tracker; Market research reports (Research and Markets, Allied Market Research, etc.) Candidates C&GT: 2) Cell & Gene Therapy reports: American Society of Gene + Cell Therapy: Q2 2022 Cell, Gene & RNA Therapy Trials C&GT: BioCentury; Alliance for Regenerative Medicine pub. April 2023 8#9Biosimilar mAbs market opportunities expanding Global Biosimilar Market Outlook¹ $20B $30B 2022 2025 $60B 2030 97 programs in development adalimumab LUCENTIS RANIBIZUMAB INJECTION "Top 6" mAbs with launched biosimilars AVASTIN bevacizumab ROMINEECTION FOR USE Remicade INFLIXIMAB Herceptin trastuzumab 21 mg/mL INJECTION FOR INTRAVENOUS USE Rituxan Rituximab Total Sales R REPLIGEN ¹Amgen Biosimilars 2022 Trend Report. 1st approvals: 2006 EU, 2015 US 2021 Sales $20.7B $3.6B $3.4B $3.2B $2.9B $2.8B $36.6B 22 additional approvals pending for 1H-23 2022 Sales $21.2B $2.9B $2.4B $2.3B $2.4B $2.1B $33.3B US FDA approved biosimilars 8² 2 4 4 5 3 26 approved 15 launched 9#10mRNA is a major new modality and market driver Leading COVID vaccine developers advancing non-COVID mRNA programs moderna +30 programs 20 non-COVID 2Pfizer $470M in mRNA vax 12.13.22 Moderna, Merck mRNA cancer vaccine slashes melanoma recurrence in Keytruda combo trial MERCK moderna R REPLIGEN BIONTECH 15 programs 15 non-COVID Growing number of large pharma companies with deep pipelines in mRNA CUREVAC 06.26.22 BioNTech/Roche mRNA Therapy for Pancreatic Cancer Inspires Early Optimism BIONTECH the RNA people® COVID program counts are from company presentations and websites December 2022 7 programs 4 non-COVID 04.20.22 Sanofi breaks ground on first-of-its-kind Evolutive Vaccine Facility in Asia sanofi 10#11Expanding addressable market now $8.5B; $23B total market Taking share, creating new markets, and delivering industry-leading revenue growth PROTEINS & AFFINITY RESINS Our market share: ~6% Our 3-year CAGR (2019-2022): >15% PROCESS ANALYTICS Our market share: 4%-5% Our 2-year CAGR (2020-2022): >25% R REPLIGEN $2.0B 24% $1.4B 17% $8.5B TAM $950M 11% CHROMATOGRAPHY Our market share: ~13% Our 3-year CAGR (2019-2022): >25% $4.1B 49% FILTRATION Our market share: ~12% (from 9%) Our 3-year CAGR (2019-2022): >60% Repligen Market Share 2022 9%-10% of TAM 2022 Y/Y franchise-level revenue for market share calc reflects franchise level growth as of our Q4 earnings call Feb. 22, 2023. 11#12Our Blueprint for Success M&A, R&D, Operational Excellence R REPLIGEN#13Our blueprint for success R REPLIGEN Strategic M&A o Rapid growth of acquired companies o Technology focus R&D Innovation and Partnerships o First-to-market product introductions o Market-leading technologies o Collaborations with industry leaders in key growth areas Operational Excellence o Capacity expansion, multi-site manufacturing o Global commercial footprint 13#14M&A accelerates our expansion, elevates our presence Our strategic acquisitions meet strict criteria: o Technology leadership o Strengthens, expands Repligen's market position o Underinvested in a key area o Strong revenue growth, margins in line with or above corporate average o Potential to be accretive to adjusted EPS in first full yet-acquisition 2014-2019: o Built out Filtration, established Analytics franchises 2020-2023: o Built out Fluid Management o Strengthening all franchises R REPLIGEN Areas of Investment to Accelerate Growth Commercial Operations Acquisition C Technologies May 2019 Highly differentiated, in-line, real-time, fast and accurate measurement ARTESYN Biosolutions December 2020 Premier integrated systems for filtration and chromatography Polymem S.A. June 2021 World class hollow-fiber; immediately expanded HF capacity 3x-4x Avitide Inc. Sept. 2021 Analytics R&D Leading-edge content player; largest most diverse ligand library, gene- therapy affinity resin focus Filtration Chromatography Proteins & Affinity Resins 14#15Creation of value through strategic acquisitions Technology differentiation, potential for growth above historical, attractive margins, near term accretion Filtration Process Analytics Fluid Management R REPLIGEN 2x 2014 1.5x 2016 Refine TANGENX TECHNOLOGY 2017 SPECTRUM LABS.COM 8x $60M (Cumulative pro forma acquisition year revenues) 2019 C TECHNOLOGIES, INC. $26M 2020 Molding NMS ARTESYN® Engineered Technology $35M 2022 total franchise revenue reflects 2022 financial results as of Feb. 22, 2023 2021 polymem ... M&A 2022 ~$500M ... ~$54M BIOFLEX SOLUTIONS .. ~$50M 15#16April 2023 M&A: FlexBiosys meets Repligen's acquisition criteria Complements and expands our Fluid Management portfolio Expands single-use Fluid Management offerings; addresses a gap In-house bag manufacturing and integration into Repligen assemblies O Further enables vertical integration and supply chain control R REPLIGEN Provides operational and commercial leverage o Complement distributor network with go direct strategy across regions O Immediate opportunity to leverage Repligen's global commercial team (vs. limited commercial footprint) o Supports assembly business growth at newly established centers in Hopkinton, MA and Waterford, Ireland Strong revenue growth potential M&A O COVID-19 related demand was catalyst for expansion of capacity and manufacturing capabilities o $5M-$6M base business revenue contribution expected in 2023 (9 mo.) Business expected to grow at 25% annually starting in 2024 o Expect acquisition to be accretive to adjusted EPS in 2024 FLEX FLEXBIOSYS Flexible Design, Accelerating Your Results 16#17FlexBiosys company profile Founded Headquarters Branchburg, NJ Employees ~30 Leadership Gayle Tarry, CEO, Customer Base DE 2009 Stan Tarry, CTO (Founder) Primarily U.S. biopharma with some C&GT FLEXBIOSYS Flexible Design, Accelerating Your Results R REPLIGEN Products and capabilities Single-use liners O 2D single-use bags 3D single-use bags Custom assemblies Facilities 22,000 sq. ft. incl. 7,500 sq. ft. clean room space (ISO Class 7) O Gusseted tubing machinery Flextreme™ 2D media bags Bottle assemblies with overmolded caps; 6 mL 20L Customer benefits of single-use Minimize risk of cross contamination Reduce cleaning costs O Shorten process turnaround time Revenue overview O O M&A $7M base (non-COVID) revenue FY22 $6-$8M base revenue FY23e 25% revenue growth FY24 FlexTainer™ 3D Process bags; for up to 2,000L bioreactors 17#18R&D innovation key to building market and technology leadership Technology Leadership LISCAL First-to-Market 10 disruptive launches K R REPLIGEN me o Upstream process intensification o Downstream single-use solutions Pre-packed columns, affinity ligands, systems, flat sheet and hollow fiber o Differentiated advanced analytics and fluid management to support systems REPLIGEN D Key Partnerships o DRS Daylight Solutions In-line process monitoring o Purolite Next-gen Protein A resins R REFLISER R&D, Partners OPUS 4.58 FlowVPX aus 18