Company: MBIO
Filing Date: 2025-04-01
Form Type: 424B3
Source: 0001104659-25-030657
Chunk: 36

Company: MUSTANG BIO, INC.
Filing Date: 2025-04-01
Form: 424B3
Chunk 36
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 determine that a product will fulfill an unmet medical need if it will provide a therapy where either
none exists or provide a therapy that may be potentially superior to an existing therapy based on efficacy or safety factors.

A drug is eligible for RMAT designation if it
is a regenerative medicine therapy which is defined as either a cell therapy, therapeutic tissue engineered product, human cell and tissue
product, or a combination therapy using any such therapies or products, it is intended to treat, modify, reverse, or cure a serious condition;
and preliminary clinical evidence indicates that the regenerative medicine therapy has the potential to address the unmet medical needs
for such conditions. Advantages of RMAT designation include all the benefits of the fast track designation, including early interactions
with FDA. The FDA must respond to a request for RMAT designation within 60 calendar days of receipt of the request. As with other
expedited development programs, if RMAT designation has been granted but, later in development, the product no longer meets the qualifying
criteria, then CBER may rescind the RMAT designation.

Moreover, a sponsor can request designation of
a product candidate as a “breakthrough therapy.” A breakthrough therapy is defined as a drug that is intended, alone or in
combination with one or more other drugs, to treat a serious or life-threatening disease or condition, and preliminary clinical evidence
indicates that the drug may demonstrate substantial improvement over existing therapies on one or more clinically significant endpoints,
such as substantial treatment effects observed early in clinical development. The FDA must take certain actions, such as holding timely
meetings and providing advice, intended to expedite the development and review of an application for approval of a breakthrough therapy.

The FDA may give a priority review designation
within 60 days of submission of a BLA or NDA to drugs that offer major advances in treatment or provide a treatment where no adequate
therapy exists. If granted, a priority review means that the goal for the FDA to review an application is six months, rather than the
standard review of ten months under current PDUFA guidelines. Products that are eligible for fast track, RMAT or breakthrough therapy
designation may be eligible to receive a priority review if the criteria for priority review are met at the time of the BLA or NDA submission.

In addition, drugs studied for their safety and
effectiveness in treating serious or life-threatening illnesses and that provide meaningful therapeutic benefit over existing treatments
may receive accelerated approval. Approval is determined on the basis of adequate and well