On September 26, 2022, the Company announced its commitment to a plan to wind down the Company’s R&D activities (the “September 2022 Restructuring”). This plan resulted in a reduction in force where the Company reduced approximately 66% of the Company’s existing workforce in early fourth quarter of 2022. Notified employees were offered separation benefits, including severance payments and temporary healthcare coverage assistance, the majority of which were paid in October 2022 as a lump sum payment. All of the severance costs associated with the September 2022 Restructuring represented cash expenditures and were recorded within research and development expense within the accompanying consolidated statement of operations.

On December 10, 2021, the Company announced its commitment to a plan to wind down the Company’s immuno-oncology program for cavrotolimod (AST-008) and the Company’s XCUR-FXN preclinical program for the treatment of Friedreich’s ataxia. The Company intended at the time to realign its research and development resources to support (i) the development of its preclinical program targeting SCN9A for neuropathic pain, (ii) the continued advancement of its partnered programs with Ipsen Biopharm Limited to develop SNA-based treatments in neuroscience targeting Huntington’s disease and Angelman syndrome, (iii) its continued advancement of its partnered program with AbbVie to develop SNA-based treatments for hair loss disorders, as well as (iv) the continued research and development of other undisclosed therapeutic product candidates. This plan resulted in a reduction in force where the Company eliminated approximately 50% of the Company’s existing workforce on a staggered basis through January 2022 as well as other cost-cutting measures.

Notified employees were offered separation benefits, including severance payments and temporary healthcare coverage assistance. In most cases, the separation benefits were paid as a lump sum in January 2022. Certain of the notified employees had employment agreements which provided for separation benefits in the form of salary continuation; these benefits were paid between February 2022 and January 2023. All of the severance costs represent cash expenditures.


	December 2021 Restructuring		September 2022 Restructuring		Total
Balance at December 31, 2021	$	1,191	$	—	$	1,191
Payments	(1,154)		(489)		(1,643)
Additions	—		488		488
Adjustments (non-cash)	11		1		12
Balance at December 31, 2022	$	48	$	—	$	48
Payments	(48)		—		(48)
Balance at December 31, 2023	$	—	$	—	$	—