Repligen Corporation 41 Seyon Street Building #1, Suite 100 Waltham, Massachusetts 02453 Repligen Reports Third Quarter 2024 Financial Results Third quarter reported revenue of $155 million, an increase of 10% year-over-

Repligen Reports Third Quarter 2024 Financial Results

WALTHAM, Mass., November 12,

2024 Repligen Corporation (NASDAQ:RGEN), a life sciences company focused on bioprocessing technology leadership, today reported financial results for its third quarter (Q3) of 2024, covering the three- and nine- month periods ended

September 30, 2024. Provided in this press release are financial performance highlights, updates to our guidance for the full year 2024 and access information for today s webcast and conference call.

Olivier Loeillot, President and Chief Executive Officer of Repligen said, I m pleased to report strong third quarter results, made possible by the

excellent execution by our team and improving market conditions. We are encouraged to see strengthening CDMO and equipment sales in the quarter, with each delivering year-over-year and sequential growth. In new modalities, we achieved record sales

in the quarter and our differentiated technology continues to serve us well. We are further encouraged by continued strength in Filtration, consumables, and Pharma, as well as order recovery in Chromatography. With clear line of sight, we are

narrowing the 2024 revenue guidance shared in our September update, maintaining the midpoint, and we are optimistic about our opportunity funnel as we move into 2025.

Q3 2024 BUSINESS HIGHLIGHTS

FINANCIAL PERFORMANCE

Q3 2024 FINANCIAL PERFORMANCE (compared to prior year, Q3 2023, except as noted) All adjusted figures are non-GAAP

and, except for earnings per share, are rounded to the nearest million.

Cash, cash equivalents and short-term investments at September 30, 2024, were $784 million, compared to

$751 million at December 31, 2023.

FINANCIAL GUIDANCE FOR FULL YEAR 2024

All Adjusted figures are non-GAAP

Our financial guidance for the full year 2024 is based on expectations for our existing business. Our GAAP and Adjusted

(non-GAAP) guidance includes the expected impact of businesses acquired in 2023 (FlexBiosys and Metenova) and excludes the impact of any potential or pending business acquisitions in 2024, and future

fluctuations in foreign currency exchange rates.

Conference Call and Webcast Access

Repligen will host a conference call and webcast today, November 12, 2024, at 8:30 a.m. ET, to discuss third quarter 2024 financial results, corporate

developments and financial guidance for 2024. 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

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 3384562.

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 in Waltham, Massachusetts, and the majority of our manufacturing sites are in 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 Adjusted (non-GAAP) measures of financial performance are included in this release: organic revenue growth, base revenue growth; adjusted cost of goods sold, adjusted gross profit and adjusted gross margin; adjusted R&D

expense and adjusted SG&A expense; adjusted income from operations and adjusted operating margin; adjusted pre-tax income; adjusted net income; adjusted earnings per share (diluted); adjusted earnings

before interest, taxes, depreciation and amortization (EBITDA), and adjusted 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 to its past performance. The Company provides the impact of foreign currency translation, to enable determination of revenue growth rates at

constant currency. To calculate the impact of foreign currency translation, the Company converts actual net sales from local currency to U.S. dollars using constant foreign currency exchange rates in the current and prior year periods.

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 and accelerated depreciation among other charges; incremental costs attributed to CEO transition; contingent consideration related to the

Company s acquisitions; intangible amortization costs; non-cash interest expense related to the accretion of the debt discount; amortization of debt issuance costs related to Company s convertible

debt; foreign currency impact of certain intercompany loans; 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.

All reconciliations of above GAAP figures

(reported or guidance) to adjusted (non-GAAP) figures are detailed in the tables included later in 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.

Forward-Looking Statements

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. The forward-looking statements in the release do not constitute guarantees of future performance. Investors are cautioned that statements in this release which are not

strictly historical statements, including, among others; statements regarding the expected impact of the Restatement (as defined in the Current Report on Form 8-K filed on September 18, 2024) and change

in accounting treatment, including on the Company s overall business operations, previously reported cash and cash equivalent balances, and strategic outlook; statements regarding the Company s internal controls over financial reporting

and ongoing internal reviews and assessments; any express or implied statements or guidance regarding current or future financial performance and position, including our updated 2024 financial guidance and related assumptions; expected

demand in the markets in which we operate (including the belief that such markets will improve and the impact of such improvement on our business); the expected performance of our business; the

expected performance and success of our strategic partnerships and integration of our acquired businesses, 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: that the Company has underestimated the scope

and impact of the Restatement, risks and uncertainties around the effectiveness of the Company s disclosure controls and procedures and the effectiveness of the Company s internal control over financial reporting, the risk that the

Company s restated financial statements may take longer to complete than expected; our ability to successfully grow our bioprocessing business; our ability to manage through and predict headwinds, including to achieve our updated 2024 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, or to close potential or

pending acquisitions (including Tantti) in a timely manner or at all, and achieve the expected benefits of such acquisitions; that demand for our products could continue to decline, which could adversely impact our future revenues, cash flows,

results of operations and financial condition; our ability to compete with larger, better financed bioprocessing 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 filings with the U.S. Securities and Exchange Commission (the Commission), including Annual Report on Form 10-K for the year ended December 31,

2023 and in subsequently filed reports with the Commission, including our Quarterly Reports on Form 10-Q (including for the quarters ended March 31, 2024 and June 30, 2024), current reports on Form 8-K, and any subsequent filings with the Commission, which are available at the Commission s website at www.sec.gov. 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. Further, investors are

cautioned that the Prior Period Financial Statements (as defined in the Current Report on Form 8-K filed on September 18, 2024), and related investor communications, should no longer be relied upon; such

communications include earnings releases, press releases, shareholder communications, investor presentations and other communications describing relevant portions of the Prior Period Financial Statements.

VP, Global Head of Investor Relations

REPLIGEN CORPORATION

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

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

REPLIGEN CORPORATION

RECONCILIATIONS OF GAAP to NON-GAAP FINANCIAL MEASURES

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

In all tables below, totals may not add due to rounding

Reconciliation of Reported Revenue (GAAP) Growth to Organic Revenue Growth (Non-GAAP)

Reconciliation of Total Revenue (GAAP) to Base Revenue (Non-GAAP)

Reconciliation of Income from Operations (GAAP) to Adjusted Income from Operations (Non-GAAP)

Reconciliation of Net (Loss) Income (GAAP) to Adjusted Net Income (Non-GAAP)

Reconciliation of (Loss) Earnings Per Share (GAAP) to Adjusted Earnings Per Share (Non-GAAP)

Reconciliation of Net Income (GAAP) to Adjusted EBITDA (Non-GAAP)

Reconciliation of Cost of Goods Sold (GAAP) to Adjusted Cost Goods Sold

Reconciliation of R&D Expense (GAAP) to Adjusted R&D Expense (Non-GAAP)

Reconciliation of SG&A Expense (GAAP) to Adjusted SG&A Expense (Non-GAAP)

Reconciliation of Net Income (GAAP) Guidance to Adjusted Net Income

Reconciliation of Earnings Per Share (GAAP) Guidance to Adjusted Earnings Per Share