In 2016, the Company entered into an agreement with Serum Institute for the prepayment of clinical PSA supply in exchange for the Company’s common stock. As of December 31, 2022 and 2021, the Company has classified $0.7 million of prepaid clinical supply as long-term as it does not anticipate utilizing the majority of the PSA supply within the next 12 months. No clinical supply was utilized during the years ended December 31, 2022 and 2021.

See also Note 15, Related Party Transactions for a description of the Pharmsynthez Loan.