Interim Financial Information	6 Months Ended
Jun. 30, 2023
Quarterly Financial Information Disclosure [Abstract]
Interim Financial Information	1. Interim Financial Information Organization and Business MediciNova, Inc. (the “Company” or “MediciNova”) was incorporated in the state of Delaware in September 2000. The Company’s common stock is listed in both the United States and Japan and trades on the Nasdaq Global Market and the Standard Market of the Tokyo Stock Exchange. The Company is a biopharmaceutical company focused on developing novel therapeutics for the treatment of serious diseases with unmet medical needs with a commercial focus on the United States market. The Company’s current strategy is to focus its development activities on MN-166 (ibudilast) for neurological and other disorders such as progressive multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), chemotherapy-induced peripheral neuropathy, degenerative cervical myelopathy, glioblastoma, substance dependence and addiction (e.g., methamphetamine dependence, opioid dependence, and alcohol dependence), prevention of acute respiratory distress syndrome, and Long COVID, and MN-001 (tipelukast) for fibrotic and other diseases such as nonalcoholic fatty liver disease (NAFLD) and idiopathic pulmonary fibrosis (IPF). The Company’s pipeline also includes MN-221 (bedoradrine) for the treatment of acute exacerbation of asthma and MN-029 (denibulin) for solid tumor cancers. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP) for interim financial information and with the instructions of the Securities and Exchange Commission (SEC) on Form 10-Q and Rule 8-03 of Regulation S-X. Accordingly, they do not include all the information and disclosures required by GAAP for complete financial statements. In the opinion of management, the condensed consolidated financial statements include all adjustments necessary, which are of a normal and recurring nature, for the fair presentation of the Company’s financial position and of the results of operations and cash flows for the periods presented. The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries. These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2022 included in the Company’s Amendment No. 1 to Annual Report on Form 10-K filed with the SEC. The results of operations for the interim period shown in this report are not necessarily indicative of the results that may be expected for any other interim period or for the full year. The balance sheet at December 31, 2022 has been derived from the audited financial statements at that date but does not include all the information and footnotes required by GAAP for complete financial statements. Principles of Consolidation The consolidated financial statements include the accounts of MediciNova, Inc. and its wholly owned subsidiaries, MediciNova Japan, Inc., MediciNova (Europe) Limited, MediciNova Europe GmbH and Avigen Inc. The financial statements of the Company’s foreign subsidiaries are measured using their local currency as the functional currency. The resulting translation adjustments are recorded as a component of other comprehensive income or loss. Intercompany transaction gains or losses at each period end are included as translation adjustments and recorded within other comprehensive income or loss. All intercompany transactions and balances are eliminated in consolidation. Segment Reporting Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company operates in a single operating segment – the acquisition and development of small molecule therapeutics for the treatment of serious diseases with unmet medical needs. Cash and Cash Equivalents Cash and cash equivalents consist of cash and other highly liquid investments including money market accounts, with original maturities of three months or less from the date of purchase. Investments Investments purchased with an original maturity of greater than three months are classified as investments. Investments are stated at fair value and are classified as current or non-current based on the nature of the securities as well as their stated maturities. Research, Development and Patents Research and development costs are expensed in the period incurred. Research and development costs primarily consist of salaries and related expenses for personnel, facilities and depreciation, research and development supplies, licenses and outside services. Such research and development costs totaled $1.6 million and $2.5 million for the three months ended June 30, 2023 and 2022, respectively, and $3.0 million and $4.5 million for the six months ended June 30, 2023 and 2022, respectively. Costs related to filing and pursuing patent applications are expensed as incurred, as recoverability of such expenditures is uncertain. The Company includes all external costs related to the filing of patents in Research, Development and Patents expenses. Such patent-related expenses totaled $0.1 million for the three months ended June 30, 2023 and 2022, respectively, and $0.2 million for the six months ended June 30, 2023 and 2022, respectively. Clinical Trial Accruals and Prepaid Expenses Costs for preclinical studies, clinical studies and manufacturing activities are recognized as research and development expenses based on an evaluation of the progress by Company vendors towards completion of specific tasks, using data such as patient enrollment, clinical site activations or information provided to the Company by such vendors regarding their actual costs incurred. Payments for these activities are based on the terms of individual contracts and payment timing may differ significantly from the period in which the services are performed. The Company determines accrual estimates through reports from and discussions with applicable personnel and outside service providers as to the progress or state of completion of studies, or the services completed. The Company’s estimates of accrued expenses as of each balance sheet date are based on the facts and circumstances known at the time. Costs that are paid in advance of performance are deferred as a prepaid expense and amortized over the service period as the services are provided. Leases The Company determines if an arrangement is a lease at inception and if so, determines whether the lease qualifies as an operating or finance lease. The Company does not recognize right-of-use assets and lease liabilities for leases with a term of 12 months or less and does not separate non-lease components from lease components. Operating lease right-of-use assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. Operating lease expense is recognized on a straight-line basis over the lease term and is included in general and administrative expenses. As most of the Company’s operating leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is the rate that the Company would expect to pay to borrow on a collateralized and fully amortizing basis over a similar term an amount equal to the lease payments in a similar economic environment. Use of Estimates The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and the accompanying notes. Actual results could differ from those estimates. Recently Issued Accounting Pronouncements In June 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-13, Financial Instruments— Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). The ASU introduced a new credit loss methodology, the Current Expected Credit Losses (“CECL”) methodology, which requires earlier recognition of credit losses, while also providing additional transparency about credit risk. The CECL methodology utilizes a lifetime “expected credit loss” measurement objective for the recognition of credit losses for loans, held-to maturity debt securities, trade receivables and other receivables measured at amortized cost at the time the financial asset is originated or acquired. Subsequent to the issuance of ASU 2016-13, the FASB issued several additional ASUs to clarify implementation guidance, provide narrow-scope improvements and provide additional disclosure guidance. In November 2019, the FASB issued an amendment making this ASU effective for fiscal years beginning after December 15, 2022 for smaller reporting companies. The new standard was effective for the Company on January 1, 2023. There was no impact on the consolidated financial statements upon adoption of this standard on January 1, 2023.

Interim Financial Information

6 Months Ended

Jun. 30, 2023

Quarterly Financial Information Disclosure [Abstract]

1. Interim Financial Information

Organization and Business

MediciNova, Inc. (the “Company” or “MediciNova”) was incorporated in the state of Delaware in September 2000. The Company’s common stock is listed in both the United States and Japan and trades on the Nasdaq Global Market and the Standard Market of the Tokyo Stock Exchange. The Company is a biopharmaceutical company focused on developing novel therapeutics for the treatment of serious diseases with unmet medical needs with a commercial focus on the United States market. The Company’s current strategy is to focus its development activities on MN-166 (ibudilast) for neurological and other disorders such as progressive multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS), chemotherapy-induced peripheral neuropathy, degenerative cervical myelopathy, glioblastoma, substance dependence and addiction (e.g., methamphetamine dependence, opioid dependence, and alcohol dependence), prevention of acute respiratory distress syndrome, and Long COVID, and MN-001 (tipelukast) for fibrotic and other diseases such as nonalcoholic fatty liver disease (NAFLD) and idiopathic pulmonary fibrosis (IPF). The Company’s pipeline also includes MN-221 (bedoradrine) for the treatment of acute exacerbation of asthma and MN-029 (denibulin) for solid tumor cancers.

Basis of Presentation

The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (GAAP) for interim financial information and with the instructions of the Securities and Exchange Commission (SEC) on Form 10-Q and Rule 8-03 of Regulation S-X. Accordingly, they do not include all the information and disclosures required by GAAP for complete financial statements. In the opinion of management, the condensed consolidated financial statements include all adjustments necessary, which are of a normal and recurring nature, for the fair presentation of the Company’s financial position and of the results of operations and cash flows for the periods presented. The accompanying unaudited condensed consolidated financial statements include the accounts of the Company and its wholly owned subsidiaries.

These financial statements should be read in conjunction with the audited consolidated financial statements and notes thereto for the year ended December 31, 2022 included in the Company’s Amendment No. 1 to Annual Report on Form 10-K filed with the SEC. The results of operations for the interim period shown in this report are not necessarily indicative of the results that may be expected for any other interim period or for the full year. The balance sheet at December 31, 2022 has been derived from the audited financial statements at that date but does not include all the information and footnotes required by GAAP for complete financial statements.

Principles of Consolidation

The consolidated financial statements include the accounts of MediciNova, Inc. and its wholly owned subsidiaries, MediciNova Japan, Inc., MediciNova (Europe) Limited, MediciNova Europe GmbH and Avigen Inc. The financial statements of the Company’s foreign subsidiaries are measured using their local currency as the functional currency. The resulting translation adjustments are recorded as a component of other comprehensive income or loss. Intercompany transaction gains or losses at each period end are included as translation adjustments and recorded within other comprehensive income or loss. All intercompany transactions and balances are eliminated in consolidation.

Segment Reporting

Operating segments are identified as components of an enterprise about which separate discrete financial information is available for evaluation by the chief operating decision-maker in making decisions regarding resource allocation and assessing performance. The Company operates in a single operating segment – the acquisition and development of small molecule therapeutics for the treatment of serious diseases with unmet medical needs.

Cash and Cash Equivalents

Cash and cash equivalents consist of cash and other highly liquid investments including money market accounts, with original maturities of three months or less from the date of purchase.

Investments

Investments purchased with an original maturity of greater than three months are classified as investments. Investments are stated at fair value and are classified as current or non-current based on the nature of the securities as well as their stated maturities.

Research, Development and Patents

Research and development costs are expensed in the period incurred. Research and development costs primarily consist of salaries and related expenses for personnel, facilities and depreciation, research and development supplies, licenses and outside services. Such research and development costs totaled $1.6 million and $2.5 million for the three months ended June 30, 2023 and 2022, respectively, and $3.0 million and $4.5 million for the six months ended June 30, 2023 and 2022, respectively.

Costs related to filing and pursuing patent applications are expensed as incurred, as recoverability of such expenditures is uncertain. The Company includes all external costs related to the filing of patents in Research, Development and Patents expenses. Such patent-related expenses totaled $0.1 million for the three months ended June 30, 2023 and 2022, respectively, and $0.2 million for the six months ended June 30, 2023 and 2022, respectively.

Clinical Trial Accruals and Prepaid Expenses

Costs for preclinical studies, clinical studies and manufacturing activities are recognized as research and development expenses based on an evaluation of the progress by Company vendors towards completion of specific tasks, using data such as patient enrollment, clinical site activations or information provided to the Company by such vendors regarding their actual costs incurred. Payments for these activities are based on the terms of individual contracts and payment timing may differ significantly from the period in which the services are performed. The Company determines accrual estimates through reports from and discussions with applicable personnel and outside service providers as to the progress or state of completion of studies, or the services completed. The Company’s estimates of accrued expenses as of each balance sheet date are based on the facts and circumstances known at the time. Costs that are paid in advance of performance are deferred as a prepaid expense and amortized over the service period as the services are provided.

Leases

The Company determines if an arrangement is a lease at inception and if so, determines whether the lease qualifies as an operating or finance lease. The Company does not recognize right-of-use assets and lease liabilities for leases with a term of 12 months or less and does not separate non-lease components from lease components. Operating lease right-of-use assets and liabilities are recognized at commencement date based on the present value of lease payments over the lease term. Operating lease expense is recognized on a straight-line basis over the lease term and is included in general and administrative expenses. As most of the Company’s operating leases do not provide an implicit rate, the Company uses its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. The incremental borrowing rate is the rate that the Company would expect to pay to borrow on a collateralized and fully amortizing basis over a similar term an amount equal to the lease payments in a similar economic environment.

Use of Estimates

The preparation of the consolidated financial statements in conformity with GAAP requires management to make estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and the accompanying notes. Actual results could differ from those estimates.

Recently Issued Accounting Pronouncements

In June 2016, the FASB issued Accounting Standards Update (“ASU”) No. 2016-13, Financial Instruments— Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments (“ASU 2016-13”). The ASU introduced a new credit loss methodology, the Current Expected Credit Losses (“CECL”) methodology, which requires earlier recognition of credit losses, while also providing additional transparency about credit risk. The CECL methodology utilizes a lifetime “expected credit loss” measurement objective for the recognition of credit losses for loans, held-to maturity debt securities, trade receivables and other receivables measured at amortized cost at the time the financial asset is originated or acquired. Subsequent to the issuance of ASU 2016-13, the FASB issued several additional ASUs to clarify implementation guidance, provide narrow-scope improvements and provide additional disclosure guidance. In November 2019, the FASB issued an amendment making this ASU effective for fiscal years beginning after December 15, 2022 for smaller reporting companies. The new standard was effective for the Company on January 1, 2023. There was no impact on the consolidated financial statements upon adoption of this standard on January 1, 2023.