Collaboration and License Agreements	12 Months Ended
Sep. 30, 2020
Collaboration And License Agreements [Abstract]
Collaboration and License Agreements	NOTE 2. COLLABORATION AND LICENSE AGREEMENTS Amgen Inc. On September 28, 2016, the Company entered into two Collaboration and License Agreements, and a Common Stock Purchase Agreement with Amgen Inc., a Delaware corporation (“Amgen”). Under one of the collaboration and license agreements (the “Second Collaboration and License Agreement” or “Olpasiran Agreement”), Amgen has received a worldwide, exclusive license to Arrowhead’s novel, RNAi Olpasiran (previously referred to as AMG 890 or ARO-LPA) program. These RNAi molecules are designed to reduce elevated lipoprotein(a), which is a genetically validated, independent risk factor for atherosclerotic cardiovascular disease. Under the other collaboration and license agreement (the “First Collaboration and License Agreement” or the “ARO-AMG1 Agreement”), Amgen received an option to a worldwide, exclusive license for ARO-AMG1, an RNAi therapy for an undisclosed genetically validated cardiovascular target. In both agreements, Amgen is wholly responsible for clinical development and commercialization. Under the terms of the agreements taken together, the Company has received $35.0 million in upfront payments, $21.5 million in the form of an equity investment by Amgen in the Company’s Common Stock, and $30.0 million in milestone payments, and may receive up to an additional $400.0 million in remaining development, regulatory and sales milestone payments. The Company is further eligible to receive up to low double-digit royalties for sales of products under the Olpasiran Agreement. In July 2019, Amgen informed the Company that it would not be exercising its option for an exclusive license for ARO-AMG1, and as such, there will be no further milestone or royalty payments under the ARO-AMG1 Agreement. The Company substantially completed its performance obligations under the Olpasiran Agreement and the ARO-AMG1 Agreement. Future milestones and royalties achieved will be recognized in their entirety when earned. In July 2020, Amgen initiated a Phase 2 clinical study, which resulted in a $20 million milestone payment to the Company. During the years ended September 30, 2020, 2019 and 2018, the Company recognized $20.1 million, $0.3 million, and $16.1 million of Revenue associated with its agreements with Amgen, respectively. As of September 30, 2020, there were $0 million in contract assets recorded as accounts receivable and $0 contract liabilities recorded as current deferred revenue on the Company’s Consolidated Balance Sheets. Janssen Pharmaceuticals, Inc. On October 3, 2018, the Company entered into a License Agreement (“Janssen License Agreement”) and a Research Collaboration and Option Agreement (“Janssen Collaboration Agreement”) with Janssen Pharmaceuticals, Inc. (“Janssen”) part of the Janssen Pharmaceutical Companies of Johnson & Johnson. The Company also entered into a Stock Purchase Agreement (“JJDC Stock Purchase Agreement”) with Johnson & Johnson Innovation-JJDC, Inc. (“JJDC”), a New Jersey corporation. Under the Janssen License Agreement, Janssen has received a worldwide, exclusive license to the Company’s JNJ-3989 (ARO-HBV) program, the Company’s third-generation subcutaneously administered RNAi therapeutic candidate being developed as a potential therapy for patients with chronic hepatitis B virus infection. Beyond the Company’s Phase 1/2 study of JNJ-3989 (ARO-HBV), Janssen is also wholly responsible for clinical development and commercialization of JNJ-3989. Under the Janssen Collaboration Agreement, Janssen will be able to select three new targets against which Arrowhead will develop clinical candidates. These candidates are subject to certain restrictions and do not include candidates that already were in the Company’s pipeline. The Company will perform discovery, optimization and preclinical research and development, entirely funded by Janssen, which on its own or in combination with Janssen development work, is sufficient to allow the filing of a U.S. Investigational New Drug application or equivalent, at which time Janssen will have the option to take an exclusive license. If the option is exercised, Janssen will be wholly responsible for clinical development and commercialization of each optioned candidate. Under the terms of the agreements taken together, the Company has received $175.0 million as an upfront payment, $75.0 million in the form of an equity investment by JJDC in Arrowhead Common Stock under the JJDC Stock Purchase Agreement, and two $25.0 million milestone payments, and may receive up to $1.6 billion in development and sales milestones payments for the Janssen License Agreement, and up to $1.9 billion in development and sales milestone payments for the three additional targets covered under the Janssen Collaboration Agreement. The Company is further eligible to receive tiered royalties up to mid-teens under the Janssen License Agreement and up to low teens under the Janssen Collaboration Agreement on product sales. The Company has evaluated these agreements in accordance with the new revenue recognition standard that became effective for the Company on October 1, 2018. The adoption of the new revenue standard did not have a material impact on the balances reported when evaluated under the superseded revenue standard. At the inception of these agreements, the Company has identified one distinct performance obligation. Regarding the Janssen License Agreement, the Company determined that the key deliverables included the license and certain R&D services including the Company’s responsibility to complete the Phase 1/2 study of JNJ-3989 (ARO-HBV) and the Company’s responsibility to ensure certain manufacturing of JNJ-3989 (ARO-HBV) drug product is completed and delivered to Janssen (the “Janssen R&D Services”). Due to the specialized and unique nature of these Janssen R&D Services, and their direct relationship with the license, the Company determined that these deliverables represent one distinct bundle and thus, one performance obligation. The Company also determined that Janssen’s option to require the Company to develop up to three new targets is not a material right, and thus, not a performance obligation at the onset of the agreement. The consideration for this option will be accounted for if and when it is exercised. The Company determined the transaction price totaled approximately $252.6 million which includes the upfront payment, the premium paid by JJDC for its equity investment in the Company, the two $25.0 million milestone payments earned and estimated payments for reimbursable Janssen R&D services to be performed. The Company has allocated the total $252.6 million initial transaction price to its one distinct performance obligation for the JNJ-3989 (ARO-HBV) license and the associated Janssen R&D Services. This revenue will be recognized using a proportional performance method (based on actual labor hours versus estimated total labor hours) beginning in October 2018 and ending as the Company’s efforts in overseeing the phase 1/2 clinical trial are completed. During the years ended September 30, 2020 and 2019, the Company recognized approximately $65.0 million and $167.5 million of Revenue associated with this performance obligation, respectively. As of September 30, 2020, there were $0 in contract assets recorded as accounts receivable, and $19.3 million of contract liabilities recorded as current deferred revenue on the Company’s Consolidated Balance Sheets. The $19.3 million of current deferred revenue is driven by the upfront payment, the premium paid by JJDC for its equity investment in the Company, and the two $25.0 million milestone payments earned, net of revenue recognized to date. The Company has begun to conduct its discovery, optimization and preclinical research and development of ARO-JNJ1, ARO-JNJ2 and ARO-JNJ3 under the Janssen Collaboration Agreement. All costs and labor hours spent by the Company will be entirely funded by Janssen. During the years ended September 30, 2020 and 2019, the Company recognized $2.9 million and $1.0 million of Revenue associated with these efforts, respectively. As of September 30, 2020, there were $0.8 million of contract assets recorded as accounts receivable, and $0 of contract liabilities recorded as current deferred revenue on the Company’s Consolidated Balance Sheets. Takeda Pharmaceuticals U.S.A., Inc. On October 7, 2020, the Company entered into an Exclusive License and Co-Funding Agreement (the “Takeda License Agreement”) with Takeda Pharmaceuticals U.S.A., Inc. (“Takeda”). Under the Takeda License Agreement, Takeda and the Company will co-develop the Company’s ARO-AAT program, the Company’s second-generation subcutaneously administered RNAi therapeutic candidate being developed as a treatment for liver disease associated with alpha-1 antitrypsin deficiency. Within the United States, ARO-AAT, if approved, will be co-commercialized under a 50/50 profit sharing structure. Outside the United States, Takeda will lead the global commercialization strategy and receive an exclusive license to commercialize ARO-AAT with the Company eligible to receive tiered royalties of 20% to 25% on net sales. The Company will receive $300.0 million as an upfront payment and is eligible to receive potential development, regulatory and commercial milestones of up to $740.0 million. The Company has evaluated the Takeda License Agreement in accordance with the new revenue recognition requirements that became effective for the Company on October 1, 2018. The adoption of the new revenue standard will not have a material impact on the balances reported when evaluated under the superseded revenue standard. At the inception of the Takeda License Agreement, the Company has identified one distinct performance obligation. The Company determined that the key deliverables included the license and certain R&D services including the Company’s responsibilities to complete the initial portion of the SEQUOIA study, to complete the ongoing phase 2 AROAAT2002 study and to ensure certain manufacturing of ARO-AAT drug product is completed and delivered to Takeda (the “Takeda R&D Services”). Due to the specialized and unique nature of these Takeda R&D services, and their direct relationship with the license, the Company determined that these deliverables represent one distinct bundle and thus, one performance obligation. Beyond the Takeda R&D Services, Takeda will be responsible for managing future clinical development and commercialization. The Company will co-fund certain of the development and commercialization costs that Takeda manages, and these co-funding amounts will be offset against amounts owed to Arrowhead, either from milestones or royalties earned, or profits earned under the 50/50 profit sharing structure for U.S. commercialization. The Company determined the initial transaction price totaled approximately $300.0 million which includes the upfront payment. The Company will exclude any future estimated milestones, royalties or profit-sharing payments from this transaction price to date. The Company will allocate the total $300.0 million initial transaction price to its one distinct performance obligation for the ARO-AAT license and the associated Takeda R&D Services. This revenue will be recognized using a proportional performance method (based on actual costs incurred versus estimated total estimated costs incurred for the Takeda R&D Services) beginning in the Company’s first fiscal quarter of fiscal 2021 and ending as the Takeda R&D Services are completed.

Collaboration and License Agreements

12 Months Ended

Sep. 30, 2020

Collaboration And License Agreements [Abstract]

NOTE 2. COLLABORATION AND LICENSE AGREEMENTS

Amgen Inc.

On September 28, 2016, the Company entered into two Collaboration and License Agreements, and a Common Stock Purchase Agreement with Amgen Inc., a Delaware corporation (“Amgen”). Under one of the collaboration and license agreements (the “Second Collaboration and License Agreement” or “Olpasiran Agreement”), Amgen has received a worldwide, exclusive license to Arrowhead’s novel, RNAi Olpasiran (previously referred to as AMG 890 or ARO-LPA) program. These RNAi molecules are designed to reduce elevated lipoprotein(a), which is a genetically validated, independent risk factor for atherosclerotic cardiovascular disease. Under the other collaboration and license agreement (the “First Collaboration and License Agreement” or the “ARO-AMG1 Agreement”), Amgen received an option to a worldwide, exclusive license for ARO-AMG1, an RNAi therapy for an undisclosed genetically validated cardiovascular target. In both agreements, Amgen is wholly responsible for clinical development and commercialization. Under the terms of the agreements taken together, the Company has received $35.0 million in upfront payments, $21.5 million in the form of an equity investment by Amgen in the Company’s Common Stock, and $30.0 million in milestone payments, and may receive up to an additional $400.0 million in remaining development, regulatory and sales milestone payments. The Company is further eligible to receive up to low double-digit royalties for sales of products under the Olpasiran Agreement. In July 2019, Amgen informed the Company that it would not be exercising its option for an exclusive license for ARO-AMG1, and as such, there will be no further milestone or royalty payments under the ARO-AMG1 Agreement.

The Company substantially completed its performance obligations under the Olpasiran Agreement and the ARO-AMG1 Agreement. Future milestones and royalties achieved will be recognized in their entirety when earned. In July 2020, Amgen initiated a Phase 2 clinical study, which resulted in a $20 million milestone payment to the Company. During the years ended September 30, 2020, 2019 and 2018, the Company recognized $20.1 million, $0.3 million, and $16.1 million of Revenue associated with its agreements with Amgen, respectively. As of September 30, 2020, there were $0 million in contract assets recorded as accounts receivable and $0 contract liabilities recorded as current deferred revenue on the Company’s Consolidated Balance Sheets.

Janssen Pharmaceuticals, Inc.

On October 3, 2018, the Company entered into a License Agreement (“Janssen License Agreement”) and a Research Collaboration and Option Agreement (“Janssen Collaboration Agreement”) with Janssen Pharmaceuticals, Inc. (“Janssen”) part of the Janssen Pharmaceutical Companies of Johnson & Johnson. The Company also entered into a Stock Purchase Agreement (“JJDC Stock Purchase Agreement”) with Johnson & Johnson Innovation-JJDC, Inc. (“JJDC”), a New Jersey corporation. Under the Janssen License Agreement, Janssen has received a worldwide, exclusive license to the Company’s JNJ-3989 (ARO-HBV) program, the Company’s third-generation subcutaneously administered RNAi therapeutic candidate being developed as a potential therapy for patients with chronic hepatitis B virus infection. Beyond the Company’s Phase 1/2 study of JNJ-3989 (ARO-HBV), Janssen is also wholly responsible for clinical development and commercialization of JNJ-3989. Under the Janssen Collaboration Agreement, Janssen will be able to select three new targets against which Arrowhead will develop clinical candidates. These candidates are subject to certain restrictions and do not include candidates that already were in the Company’s pipeline. The Company will perform discovery, optimization and preclinical research and development, entirely funded by Janssen, which on its own or in combination with Janssen development work, is sufficient to allow the filing of a U.S. Investigational New Drug application or equivalent, at which time Janssen will have the option to take an exclusive license. If the option is exercised, Janssen will be wholly responsible for clinical development and commercialization of each optioned candidate. Under the terms of the agreements taken together, the Company has received $175.0 million as an upfront payment, $75.0 million in the form of an equity investment by JJDC in Arrowhead Common Stock under the JJDC Stock Purchase Agreement, and two $25.0 million milestone payments, and may receive up to $1.6 billion in development and sales milestones payments for the Janssen License Agreement, and up to $1.9 billion in development and sales milestone payments for the three additional targets covered under the Janssen Collaboration Agreement. The Company is further eligible to receive tiered royalties up to mid-teens under the Janssen License Agreement and up to low teens under the Janssen Collaboration Agreement on product sales.

The Company has evaluated these agreements in accordance with the new revenue recognition standard that became effective for the Company on October 1, 2018. The adoption of the new revenue standard did not have a material impact on the balances reported when evaluated under the superseded revenue standard. At the inception of these agreements, the Company has identified one distinct performance obligation. Regarding the Janssen License Agreement, the Company determined that the key deliverables included the license and certain R&D services including the Company’s responsibility to complete the Phase 1/2 study of JNJ-3989 (ARO-HBV) and the Company’s responsibility to ensure certain manufacturing of JNJ-3989 (ARO-HBV) drug product is completed and delivered to Janssen (the “Janssen R&D Services”). Due to the specialized and unique nature of these Janssen R&D Services, and their direct relationship with the license, the Company determined that these deliverables represent one distinct bundle and thus, one performance obligation. The Company also determined that Janssen’s option to require the Company to develop up to three new targets is not a material right, and thus, not a performance obligation at the onset of the agreement. The consideration for this option will be accounted for if and when it is exercised.

The Company determined the transaction price totaled approximately $252.6 million which includes the upfront payment, the premium paid by JJDC for its equity investment in the Company, the two $25.0 million milestone payments earned and estimated payments for reimbursable Janssen R&D services to be performed. The Company has allocated the total $252.6 million initial transaction price to its one distinct performance obligation for the JNJ-3989 (ARO-HBV) license and the associated Janssen R&D Services. This revenue will be recognized using a proportional performance method (based on actual labor hours versus estimated total labor hours) beginning in October 2018 and ending as the Company’s efforts in overseeing the phase 1/2 clinical trial are completed. During the years ended September 30, 2020 and 2019, the Company recognized approximately $65.0 million and $167.5 million of Revenue associated with this performance obligation, respectively. As of September 30, 2020, there were $0 in contract assets recorded as accounts receivable, and $19.3 million of contract liabilities recorded as current deferred revenue on the Company’s Consolidated Balance Sheets. The $19.3 million of current deferred revenue is driven by the upfront payment, the premium paid by JJDC for its equity investment in the Company, and the two $25.0 million milestone payments earned, net of revenue recognized to date.

The Company has begun to conduct its discovery, optimization and preclinical research and development of ARO-JNJ1, ARO-JNJ2 and ARO-JNJ3 under the Janssen Collaboration Agreement. All costs and labor hours spent by the Company will be entirely funded by Janssen. During the years ended September 30, 2020 and 2019, the Company recognized $2.9 million and $1.0 million of Revenue associated with these efforts, respectively. As of September 30, 2020, there were $0.8 million of contract assets recorded as accounts receivable, and $0 of contract liabilities recorded as current deferred revenue on the Company’s Consolidated Balance Sheets.

Takeda Pharmaceuticals U.S.A., Inc.

On October 7, 2020, the Company entered into an Exclusive License and Co-Funding Agreement (the “Takeda License Agreement”) with Takeda Pharmaceuticals U.S.A., Inc. (“Takeda”). Under the Takeda License Agreement, Takeda and the Company will co-develop the Company’s ARO-AAT program, the Company’s second-generation subcutaneously administered RNAi therapeutic candidate being developed as a treatment for liver disease associated with alpha-1 antitrypsin deficiency. Within the United States, ARO-AAT, if approved, will be co-commercialized under a 50/50 profit sharing structure. Outside the United States, Takeda will lead the global commercialization strategy and receive an exclusive license to commercialize ARO-AAT with the Company eligible to receive tiered royalties of 20% to 25% on net sales. The Company will receive $300.0 million as an upfront payment and is eligible to receive potential development, regulatory and commercial milestones of up to $740.0 million.

The Company has evaluated the Takeda License Agreement in accordance with the new revenue recognition requirements that became effective for the Company on October 1, 2018. The adoption of the new revenue standard will not have a material impact on the balances reported when evaluated under the superseded revenue standard. At the inception of the Takeda License Agreement, the Company has identified one distinct performance obligation. The Company determined that the key deliverables included the license and certain R&D services including the Company’s responsibilities to complete the initial portion of the SEQUOIA study, to complete the ongoing phase 2 AROAAT2002 study and to ensure certain manufacturing of ARO-AAT drug product is completed and delivered to Takeda (the “Takeda R&D Services”). Due to the specialized and unique nature of these Takeda R&D services, and their direct relationship with the license, the Company determined that these deliverables represent one distinct bundle and thus, one performance obligation. Beyond the Takeda R&D Services, Takeda will be responsible for managing future clinical development and commercialization. The Company will co-fund certain of the development and commercialization costs that Takeda manages, and these co-funding amounts will be offset against amounts owed to Arrowhead, either from milestones or royalties earned, or profits earned under the 50/50 profit sharing structure for U.S. commercialization.

The Company determined the initial transaction price totaled approximately $300.0 million which includes the upfront payment. The Company will exclude any future estimated milestones, royalties or profit-sharing payments from this transaction price to date. The Company will allocate the total $300.0 million initial transaction price to its one distinct performance obligation for the ARO-AAT license and the associated Takeda R&D Services. This revenue will be recognized using a proportional performance method (based on actual costs incurred versus estimated total estimated costs incurred for the Takeda R&D Services) beginning in the Company’s first fiscal quarter of fiscal 2021 and ending as the Takeda R&D Services are completed.