PRELIMINARY NOTE The unaudited condensed Consolidated Financial Statements for the three-month period ended

unaudited condensed Consolidated Financial Statements for the three-month period ended March 31, 2021, included herein, have been prepared in accordance with International Accounting Standard 34 ( IAS 34 ) Interim Financial

Reporting as issued by the International Accounting Standards Board ( IASB ). The consolidated financial statements are presented in U.S. dollars. All references in this interim report to $ and U.S. dollars mean U.S.

dollars and all references to and euros mean euros, unless otherwise noted.

This interim report,

including Management s Discussion and Analysis of Financial Condition and Results of Operations, contains forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995 and Section 27A of

the Securities Act. All statements other than present and historical facts and conditions contained in this interim report, including statements regarding our future results of operations and financial position, business strategy, plans and our

objectives for future operations, are forward-looking statements. When used in this interim report, the words anticipate, believe, can, could, estimate, expect,

intend, is designed to, may, might, plan, potential, predict, objective, should, or the negative of these and similar expressions

identify forward-looking statements. These forward-looking statements are subject to numerous risks and uncertainties and are made in light of information currently available to us. Actual results, performance or events may differ materially from

those projected in any forward-looking statement. Many important factors may adversely affect such forward-looking statements and cause actual results to differ from those in any forward-looking statement, including, without limitation, the severity

and duration of the evolving COVID-19 pandemic and the resulting impact on macro-economic conditions; inconclusive clinical trial results or clinical trials failing to achieve one or more endpoints; early data

not being repeated in ongoing or future clinical trials; failures to secure required regulatory approvals; disruptions from failures by third-parties on whom we rely in connection with our clinical trials; delays or negative determinations by

regulatory authorities; changes or increases in oversight and regulation; increased competition; manufacturing delays or problems; inability to achieve enrollment targets; disagreements with our collaboration partners or failures of collaboration

partners to pursue product candidates; legal challenges, including product liability claims or intellectual property disputes; commercialization factors, including regulatory approval and pricing determinations; disruptions to access to raw

materials or starting material; delays or disruptions at our in-house manufacturing facilities; proliferation and continuous evolution of new technologies; disruptions to Calyxt s business, including

disruptions resulting from Calyxt s execution of its business model; management changes; dislocations in the capital markets; and other important factors described under Risk Factors and Special Note Regarding Forward-Looking

Statements in our Annual Report on Form 20-F filed with the Securities and Exchange Commission on March 4, 2021 (the Annual Report ) and under Risk Factors in the interim reports

that we file with the Securities and Exchange Commission. As a result of these factors, we cannot assure you that the forward-looking statements in this interim report will prove to be accurate. Furthermore, if our forward-looking statements prove

to be inaccurate, the inaccuracy may be material. In light of the significant uncertainties in these forward-looking statements, you should not regard these statements as a representation or warranty by us or any other person that we will achieve

our objectives and plans in any specified time frame or at all. We undertake no obligation to publicly update any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

We own various trademark registrations and applications, and unregistered trademarks and service marks, including Cellectis , TALEN and our corporate logos, and all such trademarks and service marks appearing in this interim report are the property of Cellectis.

The trademark Calyxt is owned by Calyxt. All other trade names, trademarks and service marks of other companies appearing in this interim report are the property of their respective holders.

Solely for convenience, the trademarks and trade names in this interim report may be referred to without the and symbols, but such

references, or the failure of such symbols to appear, should not be construed as any indication that their respective owners will not assert, to the fullest

extent under applicable law, their rights thereto. We do not intend to use or display other companies trademarks and trade names to imply a relationship with, or endorsement or sponsorship

of us by, any other companies.

As used in this interim report, the terms Cellectis, we, our,

us, and the Company refer to Cellectis S.A. and its subsidiaries, taken as a whole, unless the context otherwise requires. References to Calyxt refer to Calyxt, Inc. and its subsidiaries, taken as a whole.

PART I FINANCIAL INFORMATION

Item 1. Condensed Financial Statements (unaudited)

STATEMENTS OF CONSOLIDATED FINANCIAL POSITION

The accompanying notes form an integral part of these unaudited condensed Interim Consolidated Financial

UNAUDITED STATEMENTS OF CONSOLIDATED OPERATIONS

For the three-month period ended March 31,

$ in thousands, except per share amounts

The accompanying notes form an integral part of these unaudited condensed Interim Consolidated Financial

UNAUDITED INTERIM STATEMENTS OF CONSOLIDATED COMPREHENSIVE INCOME (LOSS)

For the three-month period ended March 31,

The accompanying notes form an integral part of these unaudited condensed Interim Consolidated Financial

UNAUDITED INTERIM STATEMENTS OF CONSOLIDATED CASH FLOWS

For the three-month period ended March 31,

The accompanying notes form an integral part of these unaudited condensed Interim Consolidated Financial

UNAUDITED STATEMENTS OF CHANGES IN CONSOLIDATED SHAREHOLDERS EQUITY

For the three-month period ended March 31,

$ in thousands, except share data

The accompanying notes form an integral part of these unaudited condensed Interim Consolidated Financial

NOTES TO THE INTERIM CONSOLIDATED FINANCIAL STATEMENTS

Cellectis S.A. (hereinafter Cellectis or we ) is a limited liability company ( soci t

anonyme ) registered and domiciled in Paris, France. We are a clinical-stage biotechnological company, employing our core proprietary technologies to develop

best-in-class products in the field of immuno-oncology.

candidates, based on gene-edited T-cells that express chimeric antigen receptors, or CARs, seek to harness the power of the immune system to target and eradicate cancer cells. Our gene-editing technologies

allow us to create allogeneic CAR T-cells, meaning they are derived from healthy donors rather than the patients themselves. Our gene editing expertise also enables us to develop product candidates that

feature additional safety and efficacy attributes, including control properties designed to prevent them from attacking healthy tissues, to enable them to tolerate standard oncology treatments, and to equip them to resist mechanisms that inhibit

immune-system activity. In addition to our focus on immuno-oncology, we are exploring the use of our gene-editing technologies in other therapeutic applications, as well as through our subsidiary, Calyxt, to deliver plant-based innovations and

solutions with substantial disruption potential across multiple industries.

Cellectis S.A., Cellectis, Inc., Cellectis Biologics Inc. (which was

incorporated on January 18, 2019) and Calyxt, Inc. are sometimes referred to as a consolidated group of companies as the Group.

While implementing health and safety measures in response to the

COVID-19 pandemic, we continued to advance our proprietary allogeneic CAR T-cell programs during the three months ended March 31, 2021.

Although the COVID-19 pandemic has slowed the enrolment of new patients, Cellectis continued to enroll patients in its

AMELI-01, BALLI-01 and MELANI-01 clinical trials during this first quarter of 2021, and each of the trials currently continues to

progress through its respective dose levels.

Despite the increasing availability of COVID-19 vaccines, the COVID-19 pandemic and government actions to contain it continue to result in significant disruptions to various public and commercial activities. With respect to clinical trials for both our proprietary allogeneic

CAR T-cell programs and programs conducted by commercial partners, enrollment of new patients and the ability to conduct patient follow-up is expected to continue to be

impacted by the COVID-19 pandemic. The exact timing of delays and overall impact of the COVID-19 pandemic to our business, preclinical studies, clinical trials and

manufacturing facility construction and initial production activity is currently unknown, and we are monitoring the pandemic as it continues to evolve.

At Calyxt, during the first quarter of 2021, the COVID-19 pandemic did not have a material impact on operations.

However, a resurgence of the COVID-19 pandemic, governmental response measures, and resulting disruptions could adversely affect Calyxt s operations and results.

The overall impact to Cellectis and Calyxt s businesses will be dependent on future developments, which are highly uncertain and difficult to

Note 2. Accounting principles

2.1 Basis for preparation

The Interim Consolidated

Financial Statements of Cellectis as of, and for the three-month period ended, March 31, 2021 were approved by our Board of Directors on May 6, 2021.

The Interim Consolidated Financial Statements are presented in U.S. dollars. See Note 2.2.

The Interim Consolidated Financial Statements as of, and for the three-month period ended March 31, 2021 have been prepared in accordance with

International Accounting Standard ( IAS ) 34 Interim Financial Reporting, as issued by the International Accounting Standards Board ( IASB ).

The Interim Consolidated Financial Statements as of and for the three-month period ended March 31, 2021 have been prepared using the same accounting

policies and methods as those applied for the year ended December 31, 2020, except as described below related to the new or amended accounting standards applied.

IFRS include International Financial Reporting Standards ( IFRS ), International Accounting Standards ( the IAS ), as well as the

interpretations issued by the Standards Interpretation Committee ( the SIC ), and the International Financial Reporting Interpretations Committee ( IFRIC ).

Application of new or amended accounting standards or new amendments

The following pronouncements and related amendments have been adopted by us from January 1, 2021 but had no significant impact on the Interim Consolidated

Financial Statements:

Accounting standards, interpretations and amendments issued but not yet effective

The following pronouncements and related amendments are applicable for accounting periods beginning after January 1, 2021. We do not anticipate that the

adoption of these pronouncements and amendments will have a material impact on our results of operations, financial position or cash flows:

2.2 Currency of the financial statements

The Interim Consolidated Financial Statements are presented in U.S. dollars, which differs from the functional currency of Cellectis, which is the euro. We

believe that this presentation enhances the comparability with peers, which primarily present their financial statements in U.S. dollars.

information (unless indicated otherwise) is presented in thousands of U.S. dollars.

The statements of financial position of consolidated entities having

a functional currency different from the U.S. dollar are translated into U.S. dollars at the closing exchange rate (spot exchange rate at the statement of financial position date) and the statements of operations, statements of comprehensive income

(loss) and statements of cash flows of such consolidated entities are translated at the average period to date exchange rate. The resulting translation adjustments are included in equity under the caption Accumulated other comprehensive income

(loss) in the Statements of Changes in Shareholders Equity.