Company: MBIO
Filing Date: 2025-04-01
Form Type: 424B3
Source: 0001104659-25-030657
Chunk: 20

Company: MUSTANG BIO, INC.
Filing Date: 2025-04-01
Form: 424B3
Chunk 20
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 a trial designed
to determine safety and tolerability of administering a second dose of MB-108 to patients who previously completed the aforementioned
first-in-human 19-patient Phase 1 trial (ClinicalTrials.gov Identifier: NCT06193174; enrolling by invitation) and (2) a trial that contemplates
two treatments of 1 x 105 plaque forming units (PFU) each, with the timing and
qualification for the second treatment outlined in detail by the protocol (ClinicalTrials.gov Identifier: NCT06614855; not yet recruiting)..

MB-106 (CD20 CAR T for B cell non-Hodgkin lymphoma (NHL), chronic lymphocytic leukemia (CLL) and autoimmune diseases)

We believe CD20 is a promising target for immunotherapy
of B-cell malignancies. CD20 is a B-cell lineage-specific phosphoprotein that is expressed in high, homogeneous density on the surface
of more than 95% of B-cell NHL and CLL. CD20 is stable on the cell surface with minimal shedding, internalization, or modulation upon
antibody binding and is present at only nanomolar levels as a soluble antigen. It is well established as an effective immunotherapy target,
with extensive studies demonstrating improved tumor responses and survival of B-NHL patients treated with rituximab and other anti-CD20
antibodies. Importantly, CD20 continues to be expressed on the lymphoma cells of most patients with relapsed B-NHL despite repetitive
rituximab treatments, and loss of CD20 expression is not a major contributor to treatment resistance. Thus, there is strong rationale
for testing CD20 CAR T cells as an immunotherapy for NHL.

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Under their IND, Fred Hutch is currently conducting
a Phase 1/2 clinical study to evaluate the anti-tumor activity and safety of administering CD20-directed third-generation CAR T cells
incorporating both 4-1BB and CD28 co-stimulatory signaling domains (MB-106) to patients with relapsed or refractory B-cell NHL or CLL
(ClinicalTrials.gov Identifier: NCT03277729). Secondary endpoints of this study include safety and toxicity, preliminary antitumor activity
as measured by overall response rate and complete remission rate, progression-free survival, and overall survival. The study is also assessing
CAR T cell persistence and the potential immunogenicity of the cells.