Mustang Bio : Corporate Presentation

Cautionary Statement

This presentation contains "forward-looking statements" within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. For such forward-looking statements, we claim the protection of the safe harbor for forward-looking statements contained in the Private Securities Litigation Reform Act of 1995. Such statements include, but are not limited to, any statements relating to our growth strategy, products and product development programs , including the timing of and our ability to make regulatory filings such as INDs and other applications and to obtain regulatory approvals for our product candidates, statements concerning the potential of therapies and product candidates, statements regarding the potential addressable market of our therapies and any other statements that are not descriptions of fact. Forward-looking statements are based on management's current expectations and are subject to risks and uncertainties that could negatively affect our business, operating results, financial condition and stock price. Factors that could cause actual results to differ materially from those currently anticipated include , among other things, risks related to whether the Company's third-party manufacturer is able to successfully perform its obligation to produce the Company's products under the manufacturing services agreement on a timely basis and to acceptable standards, disruption from the sale of the Company's manufacturing facility making it more difficult to maintain business and operational relationships, negative effects of the announcement of the consummation of the sale of the Company's manufacturing facility on the market price of the Company's common stock, significant transaction costs, the development stage of the Company's primary product candidates, our ability to obtain, perform under, and maintain financing and strategic agreements and relationships, risks relating to the results of research and development activities, risks relating to the timing of starting and completing clinical trials, uncertainties relating to preclinical and clinical testing; our dependence on third-party suppliers, our ability to attract, integrate and retain key personnel, the early stage of products under development, our need for substantial additional funds, government regulation, patent and intellectual property matters, competition, as well as other risks described in Part I, Item 1A, "Risk Factors," in our Annual Report on Form 10-K filed on March 30, 2023, subsequent Reports on Form 10-Q, and our other filings we make with the SEC. We expressly disclaim any obligation or undertaking to release publicly any updates or revisions to any forward-looking statements contained herein to reflect any change in our expectations or any changes in events, conditions or circumstances on which any such statement is based, except as may be required by law. The information contained herein is intended to be reviewed in its totality, and any stipulations, conditions or provisos that apply to a given piece of information in one part of this presentation should be read as applying mutatis mutandis to every other instance of such information appearing herein, as required by law.

This presentation also contains estimates and other statistical data made by independent parties and by us relating to market size and other data about our industry. These data involve a number of assumptions and limitations, and you are cautioned not to give undue weight to such data and estimates. In addition, projections, assumptions and estimates of our future performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk. Neither we nor our affiliates, advisors or representatives makes any representation as to the accuracy or completeness of that data or undertake to update such data after the date of this presentation.

Certain information contained in this presentation relates to or is based on studies, publications, surveys and other data obtained by third-party sources and the Company's own internal estimates and research. While the Company believes these third-party sources to be reliable as of the date of this presentation, it has not independently verified and makes not representation as to the adequacy, fairness, accuracy or completeness of, any information obtained from third-party sources.

Mustang Bio is Pioneering Innovative CAR-T Therapies for Cancer and Gene Therapies for Primary Immunodeficiencies

• ▪ Expect additional disclosure of data from MB-106 indolent lymphoma Arm of Mustang-sponsored trial, with start of first pivotal trial in Waldenstrom macroglobulinemia in second half of 2024

• ▪ Expect to treat 1st pt on groundbreaking combination Ph 1 trial of CAR-T + oncolytic virus in malignant brain tumors

• ▪ Expect to publish proof-of-concept data in a murine cancer model for in vivo CAR-T program

Key Programs

• ▪ First-in-class CD20-targeted CAR-T for non-Hodgkin lymphoma & chronic lymphocytic leukemia - First multicenter Mustang data presented at ASH in December 2023 provide early confirmation of Phase 1 Fred

Hutch trial across multiple institutions & multiple indolent histologies

-

Expect to treat 1st pt in pivotal Ph 2 trial for Waldenstrom macroglobulinemia 2H 2024; top-line data 2H 2026

• ▪ First-in-class combination of CAR-T therapy + an oncolytic virus for malignant brain tumors

• ▪ FDA granted safe-to-proceed for phase 1 trial October 2023; expect to treat first patient in 2024

• ▪ Novel platform to make CAR-Ts in the patient's own body - i.e., not in a manufacturing facility

• ▪ Expect to publish first proof-of-concept data in 2024

• ▪ Transformational gene therapies for XSCID* (rare genetic disease)

• ▪ Phase 1 investigator IND trials with modified lentiviral vector expected to start in 2024

* XSCID = X-linked severe combined immunodeficiency

Robust Pipeline of Therapies Addressing Highly Challenging Diseases

Therapeutic Modality	Product (Target)	Pre-IND	Phase 1	Registrational Phase 2
Hematologic CAR-T	MB-106 for NHL (including WM) & CLL (CD20)	Expect to start pivo macroglobulinemia	tal Waldenstrom (WM) trial in 2024
Combination CAR-T + oncolytic virus (OV)	MB-101 CAR-T for GBM (IL13Rα2) Combination	COH first-in-human (FIH) MB- Expect to treat first	101 Phase 1 complete
= MB-109 MB-108 OV for GBM	patient in 2024 UAB FIH MB-108 Phase 1 ong	oing*
In vivo CAR-Ts	TBD	Publication expected 2024
Ex-vivo Gene Therapy	MB-117 (modified vector) for newborn XSCID (IL2RG)	Investigator IND trials
MB-217 (modified vector) for previously transplanted XSCID (IL2RG)	expected to start 2024

CLL = Chronic lymphocytic leukemia

COH = City of Hope National Medical Center FIH = First-in-human

GBM = Glioblastoma

NIH = National Institutes of Health NHL = Non-Hodgkin lymphomaOV = Oncolytic virus

UAB = University of Alabama at Birmingham WM = Waldenstrom macroglobulinemia

XSCID = X-linked severe combined immunodeficiency

* Partially or totally supported by grants`

R&D Collaborators: World Class Team of Scientific Experts

• ▪ Technology licensed from City of Hope (COH), Fred Hutch Cancer Center (FHCC), Nationwide Children's Hospital, St. Jude Children's Research Hospital, & Mayo Clinic

• ▪ Research based on pioneering work by:

Dr. Stephen Forman

City of Hope

Dr. Christine Brown

City of Hope

Dr. Brian Till

FHCC

Dr. Kevin Cassady

Nationwide

Dr. Brian Sorrentino St. Jude (1958-2018)

Dr. Larry Pease

Mayo Clinic

MB-106

MB-108

MB-117, MB-217

In vivo CAR-Ts

We Engineer Patients' Cells with Goal of Long-Term Benefit

Editing T cells harnesses the immune system for precise targeting of the patient's tumor

Editing blood stem cells restores the patient's immune system crippled by genetic defect

Gene therapy

(MB-117, MB-217, MB-110*)

1. Bone marrow harvest or leukapheresis

5. Infuse cells back into patient

Stem cellStem cell

Stem Stem cell cell

Stem cell

4. Low-dose busulfan

Stem cell

2. Engineer stem cells to express normal gene

3. Cryopreservation

*MB-110 = RAG1-SCID gene therapy in-licensed from Leiden Univ. Medical Centre

Asset Purchase Agreement Closed July 28, 2023, with uBriGene - US Division of Highly Experienced Chinese CDMO*; Cell Processing Has Continued Seamlessly

• ▪ 27,000 square foot potential commercial launch sitecurrently owned by Mustang - will retain Mustang personnel & support our clinical trials

• ▪ Comprehensive cell processing capabilities, including sterility testing of final product

Lentiviral vectors to carry genetic payload are produced at academic partners & CDMOs

• ▪ Successful manufacturing of MB-106 product for all pts enrolled to date on Mustang-sponsored trial

Mustang has developed a universal platform process for autologous CAR-Ts

Day -1

Day 0

Day 2 Day 3

Day 7

Day 15+

8-day sterility

Day 19+

MB-106 Overview

MB-106: CAR-T for Non-Hodgkin Lymphoma (NHL) & Chronic Lymphocytic Leukemia (CLL)

• ▪ Competitive safety & efficacy profile vis-à-vis approved & investigational cell therapies & bispecific antibodies

• ▪ Clear regulatory pathway for autologous CAR-Ts based on FDA approval to date of 6 autologous CAR-Ts

• ▪ Currently enrolling multicenter Phase 1 Mustang-sponsored trial

• ▪ BLA strategy is to pursue indications where there are no approved CAR-Ts:

  • (1) Waldenstrom macroglobulinemia (WM)

  • (2) DLBCL relapsed from CD19 CAR-Ts

  • (3) CLL

10

Clinical development: 2 trials in progress

1.

Ongoing Fred Hutch IND study: Plan to

continue enrollment; expect publication of follicular lymphoma data in 2024

2. Mustang IND 6-center Phase 1/2 trial: Currently enrolling*

• ▪ 3-arm study targeting relapsed/refractory disease

  • - Aggressive NHL

  • - Indolent NHL

  • - CLL

• ▪ Relapses from CD19 CAR-Ts eligible in all arms

• ▪ Indolent NHL arm includes Waldenstrom (fast-to-market strategy)

• ▪ Since Mustang IND trial is using same lentiviral vector as Fred Hutch trial, FDA has allowed dose escalation to start higher than initial FHCC dose

• ▪ Additional data disclosures from indolent NHL arm expected in 2024; expect to start pivotal WM Ph 2 trial in the second half of 2024

*https://clinicaltrials.gov/ct2/show/NCT05360238