Co-Development and License Agreement	3 Months Ended
Mar. 31, 2019
Co Development And License Agreement Disclosure [Abstract]
Co-Development and License Agreement	NOTE 6 — CO-DEVELOPMENT AND LICENSE AGREEMENT On February 13, 2014, the Company signed a co-development and license agreement (the “Agreement”) with Janssen, which became effective upon completion of the Company’s initial public offering and provided for the payment of a $22.0 million license fee by the Company. Under the Agreement, Janssen, the licensor, granted the Company an exclusive license, with the right to sublicense, in the Minerva Territory, under (i) certain patent and patent applications to sell products containing any orexin 2 compound, controlled by the licensor and claimed in a licensor patent right as an active ingredient, and (ii) seltorexant for any use in humans. In addition, upon regulatory approval in the Minerva Territory (and earlier if certain default events occur), the Company will have rights to manufacture seltorexant, also known as JNJ-42847922. The Company has granted to the licensor an exclusive license, with the right to sublicense, under all patent rights and know-how controlled by the Company covering selective antagonists of orexin-2 receptors, including seltorexant, to sell those compounds outside the Minerva Territory. In consideration of the licenses granted on July 7, 2014, the Company made a license fee payment of $22.0 million, which was included as a component of research and development expense in 2014. The Company accounts for the Agreement as a joint risk-sharing collaboration in accordance with ASC 808, Collaborative Arrangements. Payments between the Company and the licensor with respect to each party’s share of seltorexant development costs that have been incurred pursuant to the joint development plan are recorded within research and development expenses or general and administrative expenses, as applicable, in the accompanying consolidated statements of operations due to the joint risk-sharing nature of the activities. On July 6, 2016, the Company and Janssen agreed that “Decision Point 2” had been reached as defined under the Agreement. As neither party exercised their right to withdraw from the Agreement, the Company paid Janssen $3.5 million and has incurred direct expenses of $0.3 million related to development activities under the current phase of development. During the three months ended March 31, 2019 and 2018, the Company recorded an expense of zero for certain development activities in accordance with the terms of the Agreement. In June 2017, the Company entered into an amendment (“the Amendment”) to the Agreement. The effectiveness of the Amendment was contingent upon approval of its terms by the European Commission and the closing of the acquisition of Actelion Ltd. by affiliates of Janssen. These conditions were subsequently met, and the Amendment became effective on August 29, 2017. Under the Amendment, Janssen has waived its right to royalties on seltorexant insomnia sales in the Minerva Territory. The Company retains all of its rights to seltorexant, including commercialization of the molecule for the treatment of insomnia and as an adjunctive therapy for MDD, which include an exclusive license in the Minerva Territory, with royalties payable by the Company to Janssen on seltorexant sales outside of the insomnia indication. Royalties on sales outside of the Minerva Territory are payable by Janssen to the Company. Janssen made an upfront payment to the Company of $30 million upon the effectiveness of the Amendment and agreed to make a $20 million payment at the start of a Phase 3 insomnia trial for seltorexant and a $20 million payment when 50% of the patients are enrolled in this trial. Janssen further agreed to waive development payments from the Company until completion of the Phase 2b development milestone. This milestone is referred to as “Decision Point 4”. Completion of the current Phase 2b studies is expected to occur in the second half of 2019. The $30 million payment and $11.2 million in previously accrued collaborative expenses, which were forgiven upon the effective date of the Amendment, are earned and recognized as revenue as the services are performed from the commencement of Phase 3 development to the completion of the development activities using the proportional performance method. The $30 million payment along with the $11.2 million in previously accrued collaborative expenses have been included under deferred revenue on the Company’s balance sheet at March 31, 2019 and December 31, 2018. In connection with the Amendment, the Company repurchased all of the approximately 3.9 million shares of its common stock previously owned by Johnson & Johnson Innovation-JJDC Inc. at a per share price of $0.0001, for an aggregate purchase price of approximately $389. As a result of the Amendment, the Company assumed strategic control of matters relating to the clinical development of seltorexant for insomnia and has no further financial obligations until after Decision Point 4. After Decision Point 4, both the Company and Janssen have the right to opt-out of the Agreement. If the Company opts-out, it collects a royalty on worldwide sales of seltorexant in the single digits with no further obligations to Janssen. If Janssen opts-out, the Minerva Territory would be expanded to include North America and the Company would pay Janssen single digit royalties on sales of seltorexant outside of the insomnia indication. If both parties elect to continue past Decision Point 4 into Phase 3, the Company would be obligated to fund the clinical trials related to insomnia, receive up to $40 million in milestone payments from Janssen, and be responsible for 40% of all costs incurred in the Phase 3 MDD program. The Company determined that the license under the Amendment is not considered to be a separate deliverable as it contains no value without the development activities performed under the Agreement. The participation in the joint steering committee under the Amendment is considered to be not separable from the development activities and therefore the two deliverables are combined into a single unit of account. The Company concluded that the milestone payments are related to future performance obligations and will be recognized as those performance obligations are performed by the Company. Similarly, the Company will recognize royalty revenues in the periods of the sale of the related products, provided that no future performance obligations exist and revenue recognition is limited to amounts for which it is probable that a significant reversal will not occur.

Co-Development and License Agreement

3 Months Ended

Mar. 31, 2019

Co Development And License Agreement Disclosure [Abstract]

NOTE 6 — CO-DEVELOPMENT AND LICENSE AGREEMENT

On February 13, 2014, the Company signed a co-development and license agreement (the “Agreement”) with Janssen, which became effective upon completion of the Company’s initial public offering and provided for the payment of a $22.0 million license fee by the Company. Under the Agreement, Janssen, the licensor, granted the Company an exclusive license, with the right to sublicense, in the Minerva Territory, under (i) certain patent and patent applications to sell products containing any orexin 2 compound, controlled by the licensor and claimed in a licensor patent right as an active ingredient, and (ii) seltorexant for any use in humans. In addition, upon regulatory approval in the Minerva Territory (and earlier if certain default events occur), the Company will have rights to manufacture seltorexant, also known as JNJ-42847922. The Company has granted to the licensor an exclusive license, with the right to sublicense, under all patent rights and know-how controlled by the Company covering selective antagonists of orexin-2 receptors, including seltorexant, to sell those compounds outside the Minerva Territory. In consideration of the licenses granted on July 7, 2014, the Company made a license fee payment of $22.0 million, which was included as a component of research and development expense in 2014.

The Company accounts for the Agreement as a joint risk-sharing collaboration in accordance with ASC 808, Collaborative Arrangements. Payments between the Company and the licensor with respect to each party’s share of seltorexant development costs that have been incurred pursuant to the joint development plan are recorded within research and development expenses or general and administrative expenses, as applicable, in the accompanying consolidated statements of operations due to the joint risk-sharing nature of the activities.

On July 6, 2016, the Company and Janssen agreed that “Decision Point 2” had been reached as defined under the Agreement. As neither party exercised their right to withdraw from the Agreement, the Company paid Janssen $3.5 million and has incurred direct expenses of $0.3 million related to development activities under the current phase of development. During the three months ended March 31, 2019 and 2018, the Company recorded an expense of zero for certain development activities in accordance with the terms of the Agreement.

In June 2017, the Company entered into an amendment (“the Amendment”) to the Agreement. The effectiveness of the Amendment was contingent upon approval of its terms by the European Commission and the closing of the acquisition of Actelion Ltd. by affiliates of Janssen. These conditions were subsequently met, and the Amendment became effective on August 29, 2017. Under the Amendment, Janssen has waived its right to royalties on seltorexant insomnia sales in the Minerva Territory. The Company retains all of its rights to seltorexant, including commercialization of the molecule for the treatment of insomnia and as an adjunctive therapy for MDD, which include an exclusive license in the Minerva Territory, with royalties payable by the Company to Janssen on seltorexant sales outside of the insomnia indication. Royalties on sales outside of the Minerva Territory are payable by Janssen to the Company. Janssen made an upfront payment to the Company of $30 million upon the effectiveness of the Amendment and agreed to make a $20 million payment at the start of a Phase 3 insomnia trial for seltorexant and a $20 million payment when 50% of the patients are enrolled in this trial. Janssen further agreed to waive development payments from the Company until completion of the Phase 2b development milestone. This milestone is referred to as “Decision Point 4”. Completion of the current Phase 2b studies is expected to occur in the second half of 2019. The $30 million payment and $11.2 million in previously accrued collaborative expenses, which were forgiven upon the effective date of the Amendment, are earned and recognized as revenue as the services are performed from the commencement of Phase 3 development to the completion of the development activities using the proportional performance method. The $30 million payment along with the $11.2 million in previously accrued collaborative expenses have been included under deferred revenue on the Company’s balance sheet at March 31, 2019 and December 31, 2018. In connection with the Amendment, the Company repurchased all of the approximately 3.9 million shares of its common stock previously owned by Johnson & Johnson Innovation-JJDC Inc. at a per share price of $0.0001, for an aggregate purchase price of approximately $389.

As a result of the Amendment, the Company assumed strategic control of matters relating to the clinical development of seltorexant for insomnia and has no further financial obligations until after Decision Point 4. After Decision Point 4, both the Company and Janssen have the right to opt-out of the Agreement.

If the Company opts-out, it collects a royalty on worldwide sales of seltorexant in the single digits with no further obligations to Janssen. If Janssen opts-out, the Minerva Territory would be expanded to include North America and the Company would pay Janssen single digit royalties on sales of seltorexant outside of the insomnia indication.

If both parties elect to continue past Decision Point 4 into Phase 3, the Company would be obligated to fund the clinical trials related to insomnia, receive up to $40 million in milestone payments from Janssen, and be responsible for 40% of all costs incurred in the Phase 3 MDD program.

The Company determined that the license under the Amendment is not considered to be a separate deliverable as it contains no value without the development activities performed under the Agreement. The participation in the joint steering committee under the Amendment is considered to be not separable from the development activities and therefore the two deliverables are combined into a single unit of account. The Company concluded that the milestone payments are related to future performance obligations and will be recognized as those performance obligations are performed by the Company. Similarly, the Company will recognize royalty revenues in the periods of the sale of the related products, provided that no future performance obligations exist and revenue recognition is limited to amounts for which it is probable that a significant reversal will not occur.