Company: MBIO
Filing Date: 2025-04-01
Form Type: 424B3
Source: 0001104659-25-030657
Chunk: 21

Company: MUSTANG BIO, INC.
Filing Date: 2025-04-01
Form: 424B3
Chunk 21
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 Finally, this study was designed so that, together with Fred Hutch,
we could determine a recommended Phase 2 dose. Fred Hutch intends to enroll approximately 50 subjects in this study, which is being led
by the Principal Investigator Mazyar Shadman, M.D., M.P.H., Associate Professor of Fred Hutch’s Clinical Research Division.

The Fred Hutch IND was amended in 2019 to incorporate
an optimized manufacturing process that had been developed in collaboration with us.

In May 2021, we announced that the FDA issued
a safe to proceed letter for our IND application allowing for initiation of a multi-center Phase 1/2 clinical study of MB-106 in patients
with relapsed or refractory B cell NHL or CLL (Clinicaltrials.gov Identifier: NCT05360238). In August 2022, the first patient was treated
in our study.

In November 2021, Mustang was awarded a grant
of approximately $2.0 million from NCI of the National Institutes of Health. This two-year award partially funded the Mustang-sponsored
multicenter trial to assess the safety, tolerability and efficacy of MB-106. In August 2023, we fully utilized the grant.

In June 2022, MB-106 received Orphan Drug Designation
for the treatment of Waldenstrom macroglobulinemia (“WM”).

In December 2023, Mustang presented preliminary
clinical data for the indolent lymphoma patients treated in the ongoing Phase 1/2 clinical study at the American Society of Hematology
(ASH) annual meeting. All 9 patients responded clinically to treatment; the observed overall response rate was 100%. All 5 follicular
lymphoma patients achieved a complete response. Among the WN patients 1 patient attained a very good partial response, and 2 patients
attained a partial response. The single patient with a hairy cell leukemia variant experienced stable disease. The safety profile
demonstrated that MB-106 was well tolerated with no occurrences of CRS above grade 1, and no ICANS of any grade was reported. Cell expansion
and persistence were also demonstrated.

In the first quarter of 2024, we completed a successful
End-of-Phase 1 meeting with the FDA regarding a potential pivotal Phase 2 single-arm clinical trial for the treatment of WM. Per the discussions,
the FDA agreed with the proposed overall design of the pivotal trial for WM at the recommended dose of 1 x 107
CAR