In July 2023 we initiated additional cost saving measures as part of our Fit for Growth program to reduce operating costs, while improving operating efficiency and effectiveness. The Fit for Growth program is expected to generate approximately $1.0 billion in gross operating expense savings by the end of 2025, some of which will be reinvested in various initiatives. The Fit for Growth program is currently estimated to include net headcount reductions of approximately 1,000 employees and we expect to incur restructuring charges ranging from approximately $260.0 million to $280.0 million.


	For the Three Months Ended March 31,
	2024
(In millions)	Severance Costs		Accelerated Depreciation and Other Costs		Total
Selling, general and administrative	$	—	$	1.4	$	1.4
Research and development	—		4.9		4.9
Restructuring charges	9.3		—		9.3
Total charges	$	9.3	$	6.3	$	15.6

Other Costs: includes costs associated with items such as asset abandonment and write-offs, facility closure costs, pretax gains and losses resulting from the termination of certain leases, employee non-severance expense, consulting fees and other costs.

Following the close of our Reata acquisition in September 2023, we implemented an integration plan designed to realize operating synergies through cost savings and avoidance. Under this initiative, we estimate we will incur total integration charges ranging from approximately $35.0 million to $40.0 million, related to severance and employment costs, which are expected to be paid by the end of 2024. These amounts were substantially incurred during 2023.


	For the Three Months Ended March 31,
	2024
(In millions)	Severance Costs		Accelerated Depreciation and Other Costs		Total
Selling, general and administrative	$	—	$	1.8	$	1.8
Research and development	—		2.7		2.7
Restructuring charges	2.2		—		2.2
Total charges	$	2.2	$	4.5	$	6.7

In connection with our acquisition of Reata we assumed responsibility for a single-tenant, build-to-suit building of approximately 327,400 square feet of office and laboratory space located in Plano, Texas, with an initial lease term of 16 years. We do not intend to occupy this building and are evaluating opportunities to sublease the property.

Charges and spending related to workforce reductions from our 2023 Fit for Growth program and Reata Integration are summarized as follows:


	For the Three Months Ended March 31,
(In millions)	2024		2023

Restructuring reserve as of December 31	$	75.4		$	35.9
Expense	11.5			7.1
Payment	(42.2)			(15.6)
Foreign currency and other adjustments	0.8			0.6
Restructuring reserve as of March 31	$	45.5		$	28.0