Repligen Corporation 41 Seyon Street Building #1, Suite 100 Waltham, Massachusetts 02453 Repligen Reports Third Quarter 2023 Financial Results and Updates Full Year 2023 Financial Guidance Reports total third quarter rev

Repligen Reports Third Quarter 2023 Financial Results

and Updates Full Year 2023 Financial Guidance

WALTHAM, Mass., October 31, 2023

Repligen Corporation (NASDAQ:RGEN), a life sciences company focused on bioprocessing technology leadership, today reported financial results for its third quarter of 2023, covering the three- and nine-month fiscal periods ended

Tony J. Hunt, Chief Executive Officer of Repligen said, While the broader challenges that have dominated our industry over

the last twelve months continued in the third quarter, we saw positive signs of recovery. Our order book strengthened by mid-quarter, delivering an overall book-to-bill of 1.07 by quarter end. In particular, orders from our Pharma customer base rebounded, with many of the projects highlighted on our second quarter call converting to purchase orders. In addition,

we continued to see momentum in the gene therapy space and delivered another growth quarter for our Analytics business. Overall, we view the third quarter as an important transition period for the company and we are cautiously optimistic about the

future in light of the strong finish on orders in the third quarter.

THIRD QUARTER BUSINESS HIGHLIGHTS

FINANCIAL PERFORMANCE

For the nine-month period YTD 2023, our base business accounted for approximately 95% of total revenue and

COVID-related revenue accounted for approximately 5%. Inorganic revenue from acquisitions accounted for less than 1%.

Income from operations (GAAP) includes $24.0 million in one-time restructuring charges, including

severance, accelerated depreciation and inventory write-off. Income from operations (GAAP) also includes an approximate $34 million contingent consideration benefit representing the change in fair value

of contingent consideration obligations associated with previous acquisitions.

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

FINANCIAL GUIDANCE FOR FISCAL YEAR 2023

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 and Metenova acquisitions and excludes the

impact of potential additional acquisitions, and future fluctuations in foreign currency exchange rates.

Our non-GAAP guidance for the fiscal year 2023 reflects

$25.0 million in adjustments, as follows:

All reconciliations of GAAP to adjusted (non-GAAP) guidance are detailed in the tables included later in this press

Conference Call and Webcast Access

Repligen will host a conference call and webcast today, October 31, 2023, at 8:30 a.m. ET, to discuss third 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 passcode 9087201.

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:

book-to-bill ratios, 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 pre-tax income; adjusted income from operations; adjusted net income; adjusted earnings per share-diluted; earnings before interest, taxes, depreciation and amortization (EBITDA) and EBITDA margin. The Company

provides base revenue and base revenue growth rates, which exclude COVID-related revenue, and the impact of acquisition revenue for current year periods that have no prior year comparables, 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 charges including the costs of severance; inventory write-off and accelerated depreciation; intangible amortization costs; contingent

consideration related to the Company s acquisitions; amortization of debt issuance costs related to 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 a substitute for the comparable financial measures

prepared in accordance with GAAP.

About Repligen Corporation

Repligen Corporation is a global life sciences 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

Forward-Looking Statement

This release contains

forward-looking statements, which are made pursuant to and in reliance upon the safe harbor provisions of federal securities laws, including the Private Securities Litigation Reform Act of 1995,

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 release which

are not strictly historical statements, including, among others, any express or implied statements or guidance regarding current or future financial performance and position, including our year 2023 financial guidance and related assumptions; 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 (including with Sartorius, Metenova and FlexBiosys); 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, risks associated with our restructuring

activities; the lasting effects of COVID-19 on our business operations and the operations of our customers and suppliers; our ability to successfully grow our bioprocessing business; 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 Metenova and 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 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. 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

ADJUSTED INCOME FROM OPERATIONS (NON-GAAP)

(Unaudited, amounts in thousands)

REPLIGEN CORPORATION

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

(Unaudited, amounts in thousands)

REPLIGEN CORPORATION

RECONCILIATION OF GAAP EARNINGS PER SHARE TO

ADJUSTED EARNINGS PER SHARE (NON-GAAP)

REPLIGEN CORPORATION

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

(Unaudited, amounts in thousands)

REPLIGEN CORPORATION

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

(Unaudited, amounts in thousands)

REPLIGEN CORPORATION

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

(Unaudited, amounts in thousands)