Repligen Corporation 41 Seyon Street Building #1, Suite 100 Waltham, Massachusetts 02453 Repligen Reports Second Quarter 2023 Financial Results and Updates Full Year 2023 Financial Guidance Reports second quarter revenue

Repligen Reports Second Quarter 2023 Financial Results

and Updates Full Year 2023 Financial Guidance

WALTHAM, Mass., August 02, 2023 Repligen Corporation (NASDAQ:RGEN), a life sciences company focused on bioprocessing technology leadership,

today reported financial results for its second quarter (Q2) and first half (H1) of 2023, covering the three- and six-month fiscal periods ended June 30, 2023. Provided in this press release are financial

performance highlights, updates to our guidance for the year 2023 and access information for today s webcast and conference call.

President and Chief Executive Officer of Repligen said, 2023 continues to be a challenging year for bioprocessing. Our base business performance in the second quarter and first half of 2023 held up reasonably well with base revenues down 9%

and 3% respectively. Our Analytics, Proteins and Chromatography franchises were all up mid-single to double digits in the quarter and

year-to-date, with most of the overall decline in revenues coming from Filtration, where the vast majority of current headwinds exist. In Cell & Gene

Therapy, sequential revenue growth of 7% in the quarter was driven by customers scaling up with our technologies and new drug approvals. Pharma base business orders weakened in the second quarter, due to inventory overhang and longer purchase

approval timelines. We remain optimistic that we will manage through these headwinds by the end of this year, supported by a growing pipeline of opportunities and projected increase in orders in the fourth quarter. However, 2023 remains a

challenging year and we now expect a decline of 7% at midpoint for our base business.

YEAR-TO-DATE FINANCIAL HIGHLIGHTS

REVENUE SUMMARY ($s in Millions)

Base revenue: excludes acquisition related revenue contribution in current periods for which there was no prior year

comparable, and excludes COVID-related revenues

GROSS PROFIT and GROSS MARGIN

NET INCOME 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.

Our financial guidance for the fiscal year 2023 is based on expectations for our existing business. Our GAAP and Adjusted

(non-GAAP) guidance includes the impact of our FlexBiosys acquisition and excludes the impact of potential additional acquisitions, and future fluctuations in foreign currency exchange rates. Our GAAP

guidance also includes an initial estimate of $6 million in severance charges associated with our plans to rebalance resources during the second half of 2023.

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

Our non-GAAP guidance for the fiscal

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, August 02, 2023, at 8:30 a.m. ET, to discuss second quarter 2023 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

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, adjusted gross margin and adjusted operating 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 base revenue growth rates, which excludes all COVID-related revenue, and the impact of acquisition revenue for current year periods that have no prior year comparables, 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 and integration costs, restructuring costs, intangible amortization costs, contingent consideration related to the Company s acquisitions, amortization of

debt issuance costs related to the Company s convertible 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

About Repligen Corporation

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 and Fluid Management, Chromatography, Process

Analytics and Proteins. Our corporate headquarters are located in Waltham, Massachusetts, and the majority of our manufacturing sites are in the U.S., with additional key sites in Estonia, France, Germany, Ireland, the Netherlands and Sweden. For

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 and related assumptions, cash and investment position, demand in the markets in which we operate, the expected performance of our business; our ability to successfully rebalance our organization

and the impact of our restructuring activities; the expected performance and success of our strategic partnerships and integration of our acquired businesses; expectations regarding the magnitude of COVID-related revenue, and management s

strategy, plans and objectives for operations or future 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 lasting effects of the COVID-19 coronavirus pandemic on our business operations and the operations of our customers and

suppliers, as well as on our revenues; our ability to successfully grow our bioprocessing business, including as a result of acquisition, commercialization or partnership opportunities; our ability to manage through and predict headwinds, including

as part of our adjusted 2023 financial guidance; our ability to develop and commercialize products and the market acceptance of our products; our ability to successfully integrate any acquired businesses (including FlexBiosys) 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 and successfully implement restructuring initiatives; our compliance with all U.S. Food and Drug Administration and European Medicines Evaluation Agency

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