Government assistance programs	12 Months Ended
Dec. 31, 2022
Government assistance programs
Government assistance programs	5. Government assistance programs DoD expense reimbursement contract In July 2020, the Company entered into the OTA Agreement with the DoD to fund the Company’s efforts in developing an antibody cocktail therapeutic to treat COVID-19. The amount of funding originally made available to the Company under the OTA Agreement was $13.3 million. In May 2021, the Company and the DoD amended the OTA Agreement, pursuant to which the DoD award was increased from $13.3 million to $17.6 million. In January 2023, the Company and the DoD modified the OTA Agreement to extend the termination date of the agreement to July 2023, at no additional cost to the government. All other terms and conditions remain the same and are in full force and effect. Under the OTA Agreement, the DoD is required to pay the Company, upon submission of invoices for approved budgeted supplies delivered and services rendered in carrying out the prototype project, within 30 calendar days of receipt of request for payment. As of December 31, 2022, the Company has received the maximum $17.6 million in expense reimbursement from the DoD under the OTA Agreement. The Company recorded contra-research and development expense of $0.6 million and $15.2 million for the years ended December 31, 2022 and 2021, respectively, in the statements of operations. There was no expense reimbursement receivable due from the DoD as of December 31, 2022. The Company had an expense reimbursement receivable balance of $2.7 million due from the DoD in prepaid expenses and other current assets as of December 31, 2021 in the accompanying balance sheets. DoD reimbursable services that have been performed but not yet billed are recorded as an unbilled receivable in prepaid expenses and other current assets in the accompanying balance sheets. There was no unbilled receivable from the DoD as of December 31, 2022. As of December 31, 2021, the Company had an unbilled receivable of $1.6 million from the DoD. Costs that have been reimbursed by the DoD but not yet expensed by the Company are recorded as a deferred research obligation liability for the period. The deferred research obligation liability is inconsequential for the year ended December 31, 2022. As of December 31, 2021, the deferred research liability of $2.0 million is included in accrued expenses and other liabilities in the accompanying balance sheets. CARES Act employee retention credit Under the CARES Act, the Company met eligibility criteria for a $0.8 million refundable employee retention credit. The Company recorded contra-expense to personnel related costs within research and development expense of $0.6 million and general and administrative expense of $0.2 million for the year ended December 31, 2022. No such amounts were recorded for the year ended December 31, 2021. The Company had an employee retention credit receivable due from the U.S. Department of Treasury of $0.8 million in prepaid expenses and other current assets as of December 31, 2022 in the accompanying balance sheets. There was no employee retention credit receivable due from the U.S. Department of Treasury as of December 31, 2021.

Government assistance programs

12 Months Ended

Dec. 31, 2022

5. Government assistance programs

DoD expense reimbursement contract

In July 2020, the Company entered into the OTA Agreement with the DoD to fund the Company’s efforts in developing an antibody cocktail therapeutic to treat COVID-19. The amount of funding originally made available to the Company under the OTA Agreement was $13.3 million. In May 2021, the Company and the DoD amended the OTA Agreement, pursuant to which the DoD award was increased from $13.3 million to $17.6 million. In January 2023, the Company and the DoD modified the OTA Agreement to extend the termination date of the agreement to July 2023, at no additional cost to the government. All other terms and conditions remain the same and are in full force and effect.

Under the OTA Agreement, the DoD is required to pay the Company, upon submission of invoices for approved budgeted supplies delivered and services rendered in carrying out the prototype project, within 30 calendar days of receipt of request for payment. As of December 31, 2022, the Company has received the maximum $17.6 million in expense reimbursement from the DoD under the OTA Agreement.

The Company recorded contra-research and development expense of $0.6 million and $15.2 million for the years ended December 31, 2022 and 2021, respectively, in the statements of operations. There was no expense reimbursement receivable due from the DoD as of December 31, 2022. The Company had an expense reimbursement receivable balance

of $2.7 million due from the DoD in prepaid expenses and other current assets as of December 31, 2021 in the accompanying balance sheets. DoD reimbursable services that have been performed but not yet billed are recorded as an unbilled receivable in prepaid expenses and other current assets in the accompanying balance sheets. There was no unbilled receivable from the DoD as of December 31, 2022. As of December 31, 2021, the Company had an unbilled receivable of $1.6 million from the DoD.

Costs that have been reimbursed by the DoD but not yet expensed by the Company are recorded as a deferred research obligation liability for the period. The deferred research obligation liability is inconsequential for the year ended December 31, 2022. As of December 31, 2021, the deferred research liability of $2.0 million is included in accrued expenses and other liabilities in the accompanying balance sheets.

CARES Act employee retention credit

Under the CARES Act, the Company met eligibility criteria for a $0.8 million refundable employee retention credit. The Company recorded contra-expense to personnel related costs within research and development expense of $0.6 million and general and administrative expense of $0.2 million for the year ended December 31, 2022. No such amounts were recorded for the year ended December 31, 2021.

The Company had an employee retention credit receivable due from the U.S. Department of Treasury of $0.8 million in prepaid expenses and other current assets as of December 31, 2022 in the accompanying balance sheets. There was no employee retention credit receivable due from the U.S. Department of Treasury as of December 31, 2021.