Cellectis S A : Corporate Presentation - May 2024

Commitment to a Cure

Corporate Presentation

May 2024

NASDAQ: CLLS

EURONEXT GROWTH: ALCLS.PA

Forward-Looking Statements

This presentation contains "forward-looking" statements within the meaning of applicable securities laws, including the Private Securities Litigation Reform Act of 1995. Forward-looking statements may be identified by words such as "designed to", "anticipate," "expected," "on track," "plan," "scheduled," "should", and "will," "would", or the negative of these and similar expressions.

These forward-looking statements, which are based on our management's current expectations and assumptions and on information currently available to management, including information provided or otherwise publicly reported by our licensed partners. Forward-looking statements about advancement, timing and progress of clinical trials (including with respect to patient enrollment and follow-up), the timing of our presentation of data and submission of regulatory filings, the adequacy of our supply of clinical vials, the operational capabilities at our manufacturing facilities, the sufficiency of cash to fund operations, the potential benefit of our product candidates and technologies, the potential payments for which Cellectis is eligible under the agreements signed between Cellectis and each of its partners, including AstraZeneca, Servier, Allogene and Iovance and the financial position of Cellectis.

These forward-looking statements are made in light of information currently available to us and are subject to numerous risks and uncertainties, including with respect to the numerous risks associated with biopharmaceutical product candidate development.

With respect to our cash runway, our operating plans, including product development plans, may change as a result of various factors, including factors currently unknown to us. Furthermore, many other important factors, including those described in our Annual Report on Form 20-F and the financial report (including the management report) for the year ended December 31, 2023 and subsequent filings Cellectis makes with the Securities Exchange Commission from time to time, as well as other known and unknown risks and uncertainties may adversely affect such forward-looking statements and cause our actual results, performance or achievements to be materially different from those expressed or implied by the forward-looking statements. Except as required by law, we assume no obligation to update these forward-looking statements publicly, or to update the reasons why actual results could differ materially from those anticipated in the forward-looking statements, even if new information becomes available in the future.

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Cellectis at a Glance

3 Clinical Trials

70+ patients dosed

in Cellectis-sponsored trials

Global GMP

Facilities

End-to-end manufacturing

autonomy

Near-Term Clinical

Catalysts

Multiple near-term UCART

clinical data updates

$156M

*as of December 31, 2023

Cash Runway into 2026**

Diversified Partnerships with Industry Leaders

~220 patients dosed to date

• Revenues > $6B in milestones + royalties
• 5 clinical trials sponsored by Cellectis' licensed partners

*Cash position includes cash, cash equivalents, restricted cash and fixed-termdeposits classified as current -financialassets. Restricted cash was $5 million as of December 31, 2023. Fixed-term	3
deposits classified as current-financial assets was $15 million as of December 31, 2023.

** cash runway includes the additional investment by AstraZeneca of $140 million, completed on May 3, 2024.

A Highly-Experienced Executive Committee

André Choulika, Ph.D.

Steven Doares, Ph.D.

Phillippe Duchateau, Ph.D.

Mark Frattini, M.D., Ph.D.

Kyung Nam-Wortman

Founder & CEO

SVP, US Manufacturing

Chief Scientific Officer

Chief Medical Officer

EVP, Chief Human

& Site Head

Resources Officer

Stephan Reynier	David Sourdive, Ph.D.	Arthur Stril	Marie-Bleuenn Terrier
Chief Regulatory &	EVP CMC & Manufacturing	Interim Chief Financial Officer	General Counsel
Pharmaceutical Compliance Officer	& Co-Founder

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UCARTs are Designed to be "Off-The-Shelf"

Scalable

Manufacturing

Reduced cost

Scalable manufacturing:

1 batch = 100s doses

Robustness

The goal is to provide

potency and consistency

to each patient

Market Access

Immediately available to all eligible patients

Control Production, Costs and Patients Safety

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Strategic Partnership with AstraZeneca

Cell & Gene Therapy R&D Collaboration

• Develop up to 10 novel products in oncology, immunology and rare diseases
• $25M upfront
• Milestones from $70M to $220M per product with tiered royalties
• AstraZeneca to cover Cellectis' research costs

Investment Agreements

• $220M equity investment (subscribed for 16 million ordinary shares and 28 million convertible preferred shares at $5.00 per share)

Note:AstraZeneca has nominated two directors to the board of directors of Cellectis. Further, certain business decisions are subject to AstraZeneca's approval. For more
information on the agreements signed with AstraZeneca, please refer to the Annual Report filed on Form 20-F and the management report for the year ended December	6
31, 2023

Experts in Gene-Editing Use TALEN®

High rates of gene editing for

knock outs and knock ins

		Efficient
In clinic since 2015	Mature	Safe	Protein / DNA interaction with
~220 patients dosed	32 base pairs recognition
		WHY
		TALEN®?
Euchromatin &	Genome	Precise	Targets desired site with a
heterochromatin	Outreach	maximum 7 bps range

Base Editors

TALEN® is a registered trademark owned by Cellectis

TALE Base Editing

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Cellectis' UCART Candidate Platform

TALEN® Powered

CD52 KO		TRAC KO
Resistance to		Minimizes risk of
alemtuzumab		GvHD

CD52

TCR

CAR-T cell

CAR

CAR20+CAR22

Targeting CD20 & CD22

For B-cell Malignancies

CAR22

Targeting CD22

For B-cell ALL

CAR123

Targeting CD123

For AML

ALL: acute lymphoblastic leukemia; AML: acute myeloid leukemia; CAR: chimeric antigen receptor; GvHD: Graft versus Host Disease; KO: Knock-Out; TCR: T-cell receptor; TRAC: T-cell receptor	8
alpha constant

Differentiated Targets & Near-Term Catalysts

	Candidate / Target	Indication	Study	Preclinical	Phase 1 Dose	Phase 1 Dose	Phase 2	Upcoming Expected Milestones
	Escalation	Expansion	Pivotal2
Owned	UCART22	ALL	BALLI-01					Data update with Recommended
CD22	NCT04150497					Phase 2 Dose (RP2D)
UCART123	AML	AMELI-01					Data update with 2-dose regimen
Fully	CD123		NCT03190278
UCART20x22	NHL	NatHaLi-01					Data update with Recommended
	Dual Target	NCT05607420					Phase 2 Dose (RP2D)
	CD20, CD22
								Licensed to:
	CEMACABTAGENE	LBCL	ALPHA3
	ANSEGEDLEUCEL
Partners	CD191
CEMACABTAGENE	CLL	ALPHA2					U.S. rights
ANSEGEDLEUCEL
NCT04416984
CD191
ALLO-7153		UNIVERSAL
Licensed	MM
BCMA	NCT04093595
ALLO-6053	MM	IGNITE
	BCMA		NCT05000450
	ALLO-3164	RCC	TRAVERSE
	CD70	NCT04696731

1. cemacabtagene ansegedleucel has been developed under a collaboration agreement between Servier and Allogene based on an exclusive license granted by Cellectis to Servier. Servier grants to Allogene exclusive rights to cemacabtagene ansegedleucel in the U.S. The ALPHA3 and ALPHA2 studies target Large B-Cell Lymphoma (LBCL) and Chronic Lymphocytic Leukemia (CLL), respectively.
2. Phase 3 may not be required if Phase 2 is registrational.
3. ALLO-715and ALLO-605 utilize TALEN® gene-editing technology pioneered and owned by Cellectis. Allogene has an exclusive license to the Cellectis technology for allogeneic products directed

at the BCMA target. Allogene holds global development and commercial rights for this investigational candidate.	9
4 ALLO-316 utilizes TALEN® gene-editing technology pioneered and owned by Cellectis. Allogene has an exclusive license to the Cellectis technology for

allogeneic products directed at the CD70 target. Allogene holds global development and commercial rights for this investigational candidate. ALL, Acute Lymphoblastic Leukemia; AML, Acute Myeloid Leukemia; NHL, Non-Hodgkin's Lymphoma; RCC, Renal Cell Carcinoma

Cellectis' UCART Platform

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