Significant Agreements	12 Months Ended
Significant Agreements	Dec. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Significant Agreements	Significant Agreements RogCon and Ionis Agreements On September 11, 2019, the Company entered into both a Cooperation and License Agreement (the “License Agreement”) with RogCon, Inc. ("RogCon"), and a Research, Collaboration, Option and License Agreement (the “Ionis Collaboration Agreement”) with Ionis Pharmaceuticals, Inc. ("Ionis"). The agreements were entered into contemporaneously to enable the parties to advance their collective efforts related to SCN2A. RogCon Agreement Under the License Agreement, RogCon granted to the Company an exclusive, worldwide license under RogCon’s intellectual property to research, develop and commercialize products for the treatment of all forms of epilepsy and/or neurodevelopmental disorders in each case caused by any mutation of the SCN2A gene. Under the License Agreement, the Company will conduct, at its own cost and expense, the research and development activities assigned to it under the research plan. In addition, the Company is responsible for reimbursing RogCon for any costs associated with research and development activities RogCon performs at the request of the Company. As part of the agreement, the Company agreed to provide up-front consideration of $2.1 million. Subsequent to September 11, 2019, the Company will reimburse RogCon for its out-of-pocket costs incurred for activities performed under the License Agreement. The Company expenses these costs as incurred as research and development. Expenses incurred for all periods presented were not material. Additionally, the Company may pay RogCon a milestone payment of $3.0 million and profit share payments. The $3.0 million milestone payment will become due when the first profit share payment has become due and certain contingent payments have become payable to Ionis under the Ionis Collaboration Agreement, which are subject to the Company exercising its option to obtain license rights to a development candidate, as well as other contingent events. The profit share payments will be based on a low-double-digit percentage of net profits, depending on sales volume. The License Agreement, unless earlier terminated, will continue until the latest of: (i) expiration of all patent rights within RogCon patents, (ii) the Company and its affiliates certify they have abandoned the research, development and commercialization of product with no intention to re-establish such activities, and (iii) no third party is obligated to pay the Company or its affiliates any amounts that comprise net sublicense revenue. Either party may terminate the License Agreement for material breach or insolvency of the other party. Additionally, the Company may terminate for convenience with prior written notice to RogCon. Upon termination by either party, all rights and licenses granted by RogCon to the Company will revert back to RogCon. Ionis Collaboration Agreement Under the Ionis Collaboration Agreement, both parties participated in research activities related to the downregulation of SCN2A gene products associated with the treatment of any and all forms of epilepsy and/or neurodevelopmental disorders in each case caused by any mutation of the SCN2A gene, other than one severe type of epilepsy. Ionis was also responsible for identifying a development candidate and conducting an IND-enabling toxicology study. The Company reimbursed Ionis for out-of-pocket costs incurred related to the research activities, identification of a development candidate and conducting an IND-enabling toxicology study. The reimbursement of out-of-pocket costs was recognized as research and development expense as incurred. The Company expensed a total of $0.7 million and $1.9 million, as research and development expense under the Ionis Collaboration Agreement for the years ended December 31, 2022 and 2021, respectively. Ionis granted the Company an exclusive option to obtain the rights and license to further develop and commercialize a development candidate in the field of epilepsy and neurodevelopmental disorders, other than Dravet Syndrome, following the results of the investigational new drug application-enabling toxicology study. The Company exercised this exclusive option in January 2022, paid a $2.0 million license fee and recognized the license fee in research and development expenses in the consolidated statement of operations during the year ended December 31, 2022. After option exercise, the Company is responsible for clinical development and commercialization of the development candidate. Ionis may be entitled to additional development milestone payments, additional milestone payments, and sales royalties or sublicense fees. The Ionis Collaboration Agreement will continue until the expiration of all payment obligations to Ionis, unless earlier terminated. Either party may terminate the Ionis Collaboration Agreement upon material breach or insolvency of the other party. Ionis may terminate if the Company fails to achieve a performance milestone. The Company may terminate for convenience with prior written notice to Ionis. Upon termination by the Company for convenience, the Company will stop selling all products, subject to certain wind-down provisions, and all products will revert back to Ionis.