Repligen Corporation 41 Seyon Street Building #1, Suite 100 Waltham, Massachusetts 02453 Repligen Reports Fourth Quarter and Full Year 2022 Financial Results Fourth quarter revenue of $186.8 million represents year-over-

Repligen Reports Fourth Quarter and Full Year 2022 Financial Results

WALTHAM, Mass., February 22, 2023 Repligen Corporation (NASDAQ:RGEN), a life sciences company focused

on bioprocessing technology leadership, today reported financial results for its fourth quarter and full year 2022. Provided in this press release are financial highlights for the three- and twelve- month periods ended December 31, 2022,

followed by our financial guidance for the year 2023, and access information for today s webcast and conference call.

Tony J. Hunt, President and

Chief Executive Officer of Repligen said, I m very pleased with our financial results and am especially encouraged by the performance of our base business which delivered organic growth of 35% in the quarter and 39% for the year. We

surpassed $800 million in revenue for 2022, representing 25% overall growth at constant currency. Strategically, 2022 was an important year for us, solidifying our leadership in process intensification, signing two strategic partnerships to

support our Analytics and Proteins franchises and completing the integration and build out of our Fluid Management business. We continue to innovate to set new standards in bioprocessing with 10 new product launches in 2022. With an expanding number

of differentiated products and customers scaling into late stage and commercial processes, we expect to deliver base organic revenue growth of 12%-16% in 2023.

Business and Financial Highlights for the Fourth Quarter and Full Year 2022

2022 Business Highlights

2022 Financial Highlights

GROSS PROFIT and GROSS MARGIN

INCOME FROM OPERATIONS

NET INCOME PER SHARE-Diluted (EARNINGS PER SHARE-Diluted)

All reconciliations of GAAP to adjusted

(non-GAAP) figures above, as well as EBITDA to adjusted EBITDA, are detailed in the reconciliation tables included later in this press release.

Financial Guidance for 2023

Our financial guidance for

the fiscal year 2023 is based on expectations for our existing business. This guidance also excludes the impact of potential additional acquisitions and future fluctuations in foreign currency exchange rates.

Our non-GAAP guidance for the fiscal year 2023 excludes the following items:

Our non-GAAP guidance for the fiscal year 2023 includes:

All reconciliations of GAAP

to adjusted (non-GAAP) guidance are detailed in the tables included later in this press release.

Conference Call and Webcast Access

Repligen will host a

conference call and webcast today, February 22, 2023, at 8:30 a.m. EST, to discuss fourth quarter and full year 2022 financial results, corporate developments and financial guidance for the year 2023. The conference call will be accessible by

dialing toll-free (844) 274-3999 for domestic callers or (412) 317-5607 for international callers. No passcode is required for the live call. In addition, a webcast will

be accessible via the Investor Relations section of the Company s website. Both the conference call and webcast will be archived for a period of time following the live event. The replay dial-in

numbers are (877) 344-7529 from the U.S., (855) 669-9658 from Canada and (412) 317-0088 for international callers. Replay

listeners must provide the passcode 3661340.

Non-GAAP Measures of Financial Performance

To supplement our financial statements, which are presented on the basis of U.S. generally accepted accounting principles (GAAP), the following non-GAAP measures of financial performance are included in this release: revenue growth rate at constant currency; adjusted gross profit and adjusted gross margin; adjusted cost of sales; adjusted R&D expense;

adjusted SG&A expense; adjusted income from operations; adjusted net income;

adjusted net income per share-diluted; earnings before interest, taxes, depreciation and amortization (EBITDA); and adjusted EBITDA. The Company provides organic revenue growth rates, which

exclude the impact of both foreign currency translation and the impact of acquisition revenue for current year periods that have no prior year comparable in order to facilitate a comparison of its current revenue performance. The Company provides

revenue growth rates at constant currency, which exclude the impact of foreign currency translation, in order to facilitate a comparison of its current revenue performance to its past revenue performance. To calculate revenue growth rates in

constant currency, the Company converts actual net sales from local currency to U.S. dollars using constant foreign currency exchange rates in the current and prior period.

The Company s non-GAAP financial results and/or non-GAAP guidance exclude

the impact of: acquisition-related inventory step-up costs, acquisition and integration costs, intangible amortization costs, contingent consideration related to the Company s acquisitions, amortization

of debt issuance costs related to Company s convertible debt, non-cash interest expense, loss on conversion of debt, and the related impact on tax of non-GAAP

charges. These costs are excluded because management believes that such expenses do not have a direct correlation to future business operations, nor do the resulting charges recorded accurately reflect the performance of our ongoing operations for

the period in which such charges are recorded.

A reconciliation of GAAP to adjusted non-GAAP financial

measures is included as an attachment to this press release. When analyzing the Company s operating performance and guidance investors should not consider non-GAAP measures as substitutable for the

comparable financial measures prepared in accordance with GAAP.

About Repligen Corporation

Repligen Corporation is a global company that develops and commercializes highly innovative bioprocessing technologies and systems that enable efficiencies in

the process of manufacturing biological drugs. We are inspiring advances in bioprocessing for the customers we serve; primarily biopharmaceutical drug developers and contract development and manufacturing organizations (CDMOs) worldwide. Our focus

areas are Filtration, Chromatography, Process Analytics, Fluid Management and Proteins. Our corporate headquarters are located in Waltham, Massachusetts, with additional administrative and manufacturing operations worldwide. The majority of our

manufacturing sites are located within the U.S. (California, Massachusetts, New Hampshire, New Jersey and New York), and we also have sites in Estonia, France, Germany, Ireland, the Netherlands and Sweden. For more information about the company,

Forward-Looking Statement

The following constitutes a Safe Harbor statement under the Private Securities Litigation Reform Act of 1995: This press release contains

forward-looking statements, which are made pursuant to the safe harbor provisions of federal securities laws, including Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as

amended. Investors are cautioned that statements in this press release which are not strictly historical statements, including, without limitation, express or implied statements or guidance regarding current or future financial performance and

position, including our year 2023 financial guidance, cash and investment position, demand in the markets in which we operate, the expected performance of our business, the expected performance and success of our strategic partnerships , the

expected performance and integration of our acquired businesses, expectations regarding manufacturing expenses, plans for gross margin expansion, our ability to continue to generate, and the magnitude of, COVID-related revenue, and management s

strategy, plans and objectives for operations or acquisitions, product development and sales, selling, general and administrative expenditures, constitute forward-looking statements identified by words like believe, expect,

may, will, should, seek, anticipate, projected, estimated or could and similar expressions. Forward-looking statements are neither historical facts nor

assurances of future performance. Because forward-looking statements relate to the future, they are subject to a number of risks and uncertainties that could cause actual results to differ materially from those anticipated, including, without

limitation, risks associated with the following: the ongoing effect of the COVID-19 coronavirus pandemic, including mitigation efforts and economic effects, on our business operations and the operations of our

customers and suppliers, as well as on our revenues; the ultimate impact of the COVID-19 coronavirus pandemic on our business or financial results; our ability to successfully grow our bioprocessing business,

including as a result of acquisition, commercialization or partnership opportunities; our ability to develop and commercialize products and the market acceptance of our products; our ability to successfully integrate any acquired businesses into our

business and achieve the expected benefits of such acquisitions; reduced demand for our products that adversely impacts our future revenues, cash flows, results of operations and financial condition; our ability to compete with larger, better

financed bioprocessing, pharmaceutical and biotechnology companies; our ability to manage expenses; our compliance with all U.S. Food and Drug Administration and EMEA regulations; our volatile stock price; and other risks detailed in Repligen s

Annual Report on Form 10-K for the year ended December 31, 2022 and in subsequently filed reports with the Securities and Exchange Commission (the Commission), including our Quarterly Reports on Form 10-Q and current reports on Form 8-K that we file with the Commission. Actual results may differ materially from those Repligen contemplated by these forward-looking

statements. Therefore, you should not rely on any of these forward-looking statements. These forward-looking statements reflect management s current views, expectations, and assumptions regarding the future of our business, future plans and

strategies, projections, anticipated events and trends, the economy and other future conditions, and are based only on information currently available to us. Repligen does not undertake to update, whether written or oral, any of these

forward-looking statements to reflect a change in its views or events or circumstances, whether as a result of new information, future development or otherwise, that occur after the date hereof except as required by law.

Global Head of Investor Relations

REPLIGEN CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited, amounts in thousands, except share and per share data)

REPLIGEN CORPORATION

RECONCILIATION OF GAAP INCOME FROM OPERATIONS TO

NON-GAAP (ADJUSTED) INCOME FROM OPERATIONS

(Unaudited, amounts in thousands)

REPLIGEN CORPORATION

RECONCILIATION OF GAAP NET INCOME TO NON-GAAP (ADJUSTED) NET INCOME

(Unaudited, amounts in thousands)

REPLIGEN CORPORATION

RECONCILIATION OF GAAP NET INCOME PER SHARE TO

NON-GAAP (ADJUSTED) NET INCOME PER SHARE

Totals may not add due to rounding.

REPLIGEN CORPORATION

RECONCILIATION OF GAAP NET INCOME TO ADJUSTED EBITDA

(Unaudited, amounts in thousands)

REPLIGEN CORPORATION

RECONCILIATION OF GAAP COST OF SALES TO NON-GAAP (ADJUSTED) COST OF SALES

(Unaudited, amounts in thousands)

REPLIGEN CORPORATION

RECONCILIATION OF GAAP R&D EXPENSE TO NON-GAAP (ADJUSTED) R&D EXPENSE