Royalty purchase liability	3 Months Ended
Mar. 31, 2026
Royalty Purchase Liability [Abstract]
Royalty purchase liability	7. Royalty purchase liability Pursuant to the Company's Amended and Restated Purchase and Sale Agreement (as amended, the Royalty Agreement) with Clarus IV Galera Royalty AIV, L.P., Clarus IV-A, L.P., Clarus IV-B, L.P., Clarus IV-C, L.P. and Clarus IV-D, L.P. (collectively, Blackstone or Blackstone Life Sciences), the Company has received $117.5 million in aggregate proceeds. Proceeds from the Royalty Agreement were accounted as debt on the accompanying consolidated balance sheets. Interest expense was imputed based on the estimated royalty repayment period, which took into consideration the probability and timing of obtaining approval from the U.S. Food and Drug Administration (FDA) and the potential future revenue from commercializing its historical product candidates, and which resulted in a corresponding increase in the liability balance. The Company suspended recognizing interest expense on the royalty purchase liability after October 2023, as the result of the uncertainty of any future royalties following its decision to discontinue the rucosopasem GRECO trials and that it was not feasible with its current resources for the Company to conduct another Phase 3 trial of avasopasem. Accordingly, no interest was recognized during the three months ended March 31, 2026 and 2025. In August 2025, the Royalty Agreement was amended, which reduced the royalty rate on net sales of avasopasem and rucosopasem to four percent (4%). The amendment was accounted for as a modification of debt to which no immediate gain or loss is recognized. In connection with the sale of the Company’s dismutase mimetics assets to Biossil in October 2025, the Company assigned and Biossil assumed all rights and obligations under the amended Royalty Agreement, and Blackstone acknowledged that it would look solely to Biossil to pay and perform the obligations and liabilities under the amended Royalty Agreement. Accordingly, the Company has extinguished the royalty purchase liability from its consolidated balance sheet, recording a $151.0 million noncash gain on the extinguishment in its consolidated statement of operations for the year ended December 31, 2025.

Royalty purchase liability

3 Months Ended

Mar. 31, 2026

Royalty Purchase Liability [Abstract]

Pursuant to the Company's Amended and Restated Purchase and Sale Agreement (as amended, the Royalty Agreement) with Clarus IV Galera Royalty AIV, L.P., Clarus IV-A, L.P., Clarus IV-B, L.P., Clarus IV-C, L.P. and Clarus IV-D, L.P. (collectively, Blackstone or Blackstone Life Sciences), the Company has received $117.5 million in aggregate proceeds. Proceeds from the Royalty Agreement were accounted as debt on the accompanying consolidated balance sheets. Interest expense was imputed based on the estimated royalty repayment period, which took into consideration the probability and timing of obtaining approval from the U.S. Food and Drug Administration (FDA) and the potential future revenue from commercializing its historical product candidates, and which resulted in a corresponding increase in the liability balance.

The Company suspended recognizing interest expense on the royalty purchase liability after October 2023, as the result of the uncertainty of any future royalties following its decision to discontinue the rucosopasem GRECO trials and that it was not feasible with its current resources for the Company to conduct another Phase 3 trial of avasopasem. Accordingly, no interest was recognized during the three months ended March 31, 2026 and 2025.

In August 2025, the Royalty Agreement was amended, which reduced the royalty rate on net sales of avasopasem and rucosopasem to four percent (4%). The amendment was accounted for as a modification of debt to which no immediate gain or loss is recognized.

In connection with the sale of the Company’s dismutase mimetics assets to Biossil in October 2025, the Company assigned and Biossil assumed all rights and obligations under the amended Royalty Agreement, and Blackstone acknowledged that it would look solely to Biossil to pay and perform the obligations and liabilities under the amended Royalty Agreement. Accordingly, the Company has extinguished the royalty purchase liability from its consolidated balance sheet, recording a $151.0 million noncash gain on the extinguishment in its consolidated statement of operations for the year ended December 31, 2025.