Subsequent Events	12 Months Ended
Dec. 31, 2025
Subsequent Events [Abstract]
Subsequent Events	16. Subsequent events On February 4, 2026, the Company entered into an Open Market Sale Agreement, or the 2026 Sale Agreement, with Jefferies LLC, pursuant to which the Company may elect to issue and sell shares of its common stock having an aggregate offering price of up to $200.0 million in such quantities and on such minimum price terms as the Company sets from time to time through Jefferies LLC as the Company's sales agent. The Company has agreed to pay Jefferies LLC an aggregate commission equal to up to 3.0% of the gross proceeds of the sales under the agreement. To date, no sales of common stock have occurred under the 2026 Sale Agreement. On February 4, 2026, or the Closing Date, the Company entered into a loan and security agreement, or the Hercules Loan Agreement, with certain lenders and Hercules Capital, Inc. in its capacity as administrative agent and collateral agent for itself and the lenders party thereto. The Hercules Loan Agreement provides for a senior secured term loan facility in an aggregate principal amount of up to $200.0 million, or the Hercules Term Loan Facility. An initial term loan of $40.0 million, or the Tranche 1A Loan, was funded under the Hercules Term Loan Facility on the Closing Date. In addition to the Tranche 1A Loan, the Hercules Term Loan Facility includes up to six additional term loan tranches providing up to an aggregate $160.0 million in additional loan commitments (collectively with the Tranche 1A Loan, the Term Loans). The final tranche of $50.0 million will be available subject to future approval by the lenders’ investment committee. The tranches will be available up to 60 months after the Closing Date, so long as the Company satisfies certain conditions precedent, including compliance with financial covenants, the continued accuracy of the representations and warranties provided in the Hercules Loan Agreement, and satisfaction of certain performance and financing milestones. The Hercules Term Loan Facility has a maturity date of February 1, 2031, or the Maturity Date. Upon repayment of the Term Loans (whether at the Maturity Date or upon earlier prepayment), the Company is required to pay an exit fee equal to (i) 3.95% of the principal amount being repaid, if repaid on or within 24 months of the Closing Date, (ii) 5.75% of the principal amount being repaid, if repaid more than 24 months after the Closing Date and on or within 48 months of the Closing Date, and (iii) 6.45% of the principal amount being repaid, if repaid thereafter. Net proceeds from the Tranche 1A Loan were approximately $38.4 million, after deducting estimated debt issuance costs and fees and expenses. The Hercules Term Loan Facility will accrue interest at an annual rate determined by reference to the Prime Rate as reported in the Wall Street Journal, with interest rate floors that range from 7.95% (with respect to the Tranche 1A Loan funded on the Closing Date, among other tranches) to 9.25% depending on the tranche. The Hercules Term Loan Facility provides for payment of interest only until (a) 48 months after the Closing Date or (b) if certain performance and financing milestones are satisfied, 60 months after the Closing Date. Accrued interest on the Term Loans is payable on the first business day of each month. Upon an Event of Default (as defined in the Hercules Loan Agreement), the interest rate will automatically increase by an additional 4.00% per annum. The Term Loans may be prepaid at any time, subject to a prepayment premium equal to (i) 3.00% of the aggregate outstanding principal amount being prepaid, if prepaid on or within 12 months of the Closing Date; (ii) 2.00% of the aggregate outstanding principal amount being prepaid, if prepaid more than 12 months after the Closing Date and on or within 24 months of the Closing Date; (iii) 1.00% of the aggregate outstanding principal amount being prepaid, if prepaid more than 24 months after the Closing Date and on or within 36 months of the Closing Date; and (iv) 0.00% thereafter, and the exit fee described above. Pursuant to the Hercules Loan Agreement, all of the Company’s obligations under the Hercules Loan Agreement are secured by a first lien perfected security interest on substantially all of the Company’s existing and after-acquired assets, subject to customary exceptions. The Hercules Loan Agreement contains certain representations and warranties, affirmative covenants, negative covenants, financial covenants, and conditions that are customarily required for similar financings. In addition, unless either (i) the Company’s market capitalization is greater than or equal to $450.0 million and an aggregate of no more than $85.0 million in principal amount is outstanding under the Term Loans or (ii) the Company’s market capitalization is greater than or equal to $750.0 million, the Company must at all other times maintain unrestricted cash and cash equivalents of at least 50% of the outstanding loan amount, decreasing to 40% and 35% upon satisfaction of certain performance and financing milestones. The Hercules Loan Agreement also contains certain customary Events of Default which include, among others, non-payment of principal, interest, or fees, violation of covenants, inaccuracy of representations and warranties, bankruptcy and insolvency events, material judgments, cross-defaults to material contracts, certain material regulatory-related events and events constituting a change of control. The occurrence of an Event of Default could result in, among other things, the declaration that all outstanding principal and interest under the Hercules Term Loan Facility are immediately due and payable in whole or in part. In connection with the entry into the Hercules Loan Agreement, the loan and security agreement discussed in Note 11, Loan and security agreement, was terminated, effective as of February 2, 2026, and the lender’s security interest in the Company’s assets and property was released. On March 13, 2026, the Company received notification from Shionogi that the first patient has been dosed in the Phase 2 study of MZE001 for Pompe disease. Pursuant to the terms of the Shionogi License Agreement, the Company expects to receive a $20.0 million clinical development milestone payment in connection with the initiation of this clinical study.

Subsequent Events

12 Months Ended

Dec. 31, 2025

16.

Subsequent events

On February 4, 2026, the Company entered into an Open Market Sale Agreement, or the 2026 Sale Agreement, with Jefferies LLC, pursuant to which the Company may elect to issue and sell shares of its common stock having an aggregate offering price of up to $200.0 million in such quantities and on such minimum price terms as the Company sets from time to time through Jefferies LLC as the Company's sales agent. The Company has agreed to pay Jefferies LLC an aggregate commission equal to up to 3.0% of the gross proceeds of the sales under the agreement. To date, no sales of common stock have occurred under the 2026 Sale Agreement.

On February 4, 2026, or the Closing Date, the Company entered into a loan and security agreement, or the Hercules Loan Agreement, with certain lenders and Hercules Capital, Inc. in its capacity as administrative agent and collateral agent for itself and the lenders party thereto. The Hercules Loan Agreement provides for a senior secured term loan facility in an aggregate principal amount of up to $200.0 million, or the Hercules Term Loan Facility. An initial term loan of $40.0 million, or the Tranche 1A Loan, was funded under the Hercules Term Loan Facility on the Closing Date. In addition to the Tranche 1A Loan, the Hercules Term Loan Facility includes up to six additional term loan tranches providing up to an aggregate $160.0 million in additional loan commitments (collectively with the Tranche 1A Loan, the Term Loans). The final tranche of $50.0 million will be available subject to future approval by the lenders’ investment committee. The tranches will be available up to 60 months after the Closing Date, so long as the Company satisfies certain conditions precedent, including compliance with financial covenants, the continued accuracy of the representations and warranties provided in the Hercules Loan Agreement, and satisfaction of certain performance and financing milestones.

The Hercules Term Loan Facility has a maturity date of February 1, 2031, or the Maturity Date. Upon repayment of the Term Loans (whether at the Maturity Date or upon earlier prepayment), the Company is required to pay an exit fee equal to (i) 3.95% of the principal amount being repaid, if repaid on or within 24 months of the Closing Date, (ii) 5.75% of the principal amount being repaid, if repaid more than 24 months after the Closing Date and on or within 48 months of the Closing Date, and (iii) 6.45% of the principal amount being repaid, if repaid thereafter. Net proceeds from the Tranche 1A Loan were approximately $38.4 million, after deducting estimated debt issuance costs and fees and expenses.

The Hercules Term Loan Facility will accrue interest at an annual rate determined by reference to the Prime Rate as reported in the Wall Street Journal, with interest rate floors that range from 7.95% (with respect to the Tranche 1A Loan funded on the Closing Date, among other tranches) to 9.25% depending on the tranche. The Hercules Term Loan Facility provides for payment of interest only until (a) 48 months after the Closing Date or (b) if certain performance and financing milestones are satisfied, 60 months after the Closing Date. Accrued interest on the Term Loans is payable on the first business day of each month. Upon an Event of Default (as defined in the Hercules Loan Agreement), the interest rate will automatically increase by an additional 4.00% per annum.

The Term Loans may be prepaid at any time, subject to a prepayment premium equal to (i) 3.00% of the aggregate outstanding principal amount being prepaid, if prepaid on or within 12 months of the Closing Date; (ii) 2.00% of the aggregate outstanding principal amount being prepaid, if prepaid more than 12 months after the Closing Date and on or within 24 months of the Closing Date; (iii) 1.00% of the aggregate outstanding principal amount being prepaid, if prepaid more than 24 months after the Closing Date and on or within 36 months of the Closing Date; and (iv) 0.00% thereafter, and the exit fee described above.

Pursuant to the Hercules Loan Agreement, all of the Company’s obligations under the Hercules Loan Agreement are secured by a first lien perfected security interest on substantially all of the Company’s existing and after-acquired assets, subject to customary exceptions.

The Hercules Loan Agreement contains certain representations and warranties, affirmative covenants, negative covenants, financial covenants, and conditions that are customarily required for similar financings. In addition, unless either (i) the Company’s market capitalization is greater than or equal to $450.0 million and an aggregate of no more than $85.0 million in principal amount is outstanding under the Term Loans or (ii) the Company’s market capitalization is greater than or equal to $750.0 million, the Company must at all other times maintain unrestricted cash and cash equivalents of at least 50% of the outstanding loan amount, decreasing to 40% and 35% upon satisfaction of certain performance and financing milestones.

The Hercules Loan Agreement also contains certain customary Events of Default which include, among others, non-payment of principal, interest, or fees, violation of covenants, inaccuracy of representations and warranties, bankruptcy and insolvency events, material judgments, cross-defaults to material contracts, certain material regulatory-related events and events constituting a change of control. The occurrence of an Event of Default could result in, among other things, the declaration that all outstanding principal and interest under the Hercules Term Loan Facility are immediately due and payable in whole or in part.

In connection with the entry into the Hercules Loan Agreement, the loan and security agreement discussed in Note 11, Loan and security agreement, was terminated, effective as of February 2, 2026, and the lender’s security interest in the Company’s assets and property was released.

On March 13, 2026, the Company received notification from Shionogi that the first patient has been dosed in the Phase 2 study of MZE001 for Pompe disease. Pursuant to the terms of the Shionogi License Agreement, the Company expects to receive a $20.0 million clinical development milestone payment in connection with the initiation of this clinical study.