Note 5 – Property, Plant and Equipment, and Fixed Assets – Construction in Process

On May 18, 2023, the Company entered into an Asset Purchase Agreement with uBriGene (Boston) Biosciences, Inc. (“uBriGene”), as amended by a first amendment thereto, dated as of June 29, 2023, and further amended by a second amendment thereto, dated as of July 28, 2023,  pursuant to which the Company has agreed, subject to the terms and conditions therein, to sell its leasehold interest in its cell processing facility located in Worcester, Massachusetts (the “Facility”) and associated assets relating to the manufacturing and production of cell and gene therapies at the Facility to uBriGene. On July 28, 2023, the Company completed the sale of the assets relating to the manufacturing and production of cell and gene therapies at the Facility.

In connection with the sale of such assets, the Company received base proceeds of $6.0 million for the assets and lab supplies on-hand as of the transaction date. Based on the fair value of the consideration received and the relative fair value

allocation of the consideration, the Company recorded a gain of $1.5 million in the Statements of Operations, for the year ended December 31, 2023. The Company recorded approximately $0.2 million of the consideration as deferred income, which will be recognized upon the transfer of the lease. The Company will record adjustments to the fair value of the potential future consideration each reporting period, prospectively.

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Mustang’s property, plant and equipment consisted of the following:

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Depreciation expense for the years ended December 31, 2023 and 2022, was approximately $1.9 million and $2.7 million, respectively, and was recorded in research and development expense in the Statements of Operations.

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Fixed assets – construction in process primarily reflects buildout costs and equipment that have not yet been placed into service. For the years ended December 31, 2023, and 2022, fixed assets – construction in process was approximately $29,000 and $1.0 million, respectively.