MediciNova, Inc. 2009 Statements in this presentation that are not historical in nature constitute forward looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform A

Sales 2008** Compound Sponsor Side Effects $2.3 Billion Copaxone Teva Sanofi Aventis Pain, redness, swelling, itching, chest pain, weakness, infection, nausea, anxiety are most common, also heart palpitations and trouble breathing after injection $2.2 Billion Avonex Biogen Idec Depression and flu like symptoms most common, also liver injury, severe allergic reactions, drop in red/white blood cell count $1.9 Billion Rebif Serono Pfizer Depression and flu like symptoms most common, also liver problems, injection site problems, severe allergic reactions, trouble breathing/loss of consciousness $1.6 Billion Betaseron Bayer Lymphopenia, injection site reaction, asthenia, flu like symptoms are most common, also necrosis at injection site $589 Million Tysabri Biogen Idec Infections, depression, pneumonia, acute hypersensitivity reactions, appendicitis most common, also liver damage, PML Multiple Sclerosis Market* Multiple Sclerosis Market* 46 *All these top selling drugs for MS are immunomodulators **Source: Company annual reports 2008 MediciNova, Inc. 2009 47 MN 166 was very well tolerated in Phase II study: 89% (264 of 297) of subjects completed the first 12 months of the study 82.5% (245 of 297) of subjects completed the full 24 months of the study Discontinuation due to adverse effects was infrequent (5.1% in 60 mg/day for 24 months, 2.1% in 30 mg/day for 24 months, 2.0% in placebo to 60 mg/day, 1.9% in placebo to 30 mg/day) Adverse effects were generally mild and self limiting GI adverse effects as a group and depression were the only adver se events to occur more frequently in MN 166 treated than in placebo treated subjects Tolerance to the GI side effects occurred rapidly (2 4 days) and tended to occur early in treatment whether MN 166 treatment was initiated in Year 1 or Year 2 Mild to moderate depression was reported in 8 subjects; depression is co mmon in MS patients and was reported only towards the end of the study No significant increase in adverse laboratory or ECG findings wa s observed 20 serious adverse events were reported; all were not or unlikely to be attributable to treatment No deaths occurred in the study MN 166 Overview Safety MN 166 Overview Safety MediciNova, Inc. 2009 Compound Sponsor Current Phase Safety Profile from Phase II trials MN 166 MediciNova Phase II Mild, transient GI upset FTY 720 Novartis Phase III Blood pressure Heart rate Dyspnea Liver enzymes Lymphopenia Cladribine Merck Serono Phase III Fever Nausea, Vomiting Leucopenia BG 12 Biogen Idec Phase III H/A, Nasopharyngitis GI disorders Liver enzymes Laquinimod Teva Phase III Liver enzymes Arthralgia Fibrinogen Hemoglobin MN 166 Safety Comparison MN 166 Safety Comparison with Other Oral Agents with Other Oral Agents 48

New Lesions at Month 2 72 64 56 # Patients w. 1 PBH (% of Pts. w. New Lesions) 41 (56.9%) 33 (51.6%) 28 (50%) Mean Proportion of Lesions Evolving to PBH 0.24 0.20 0.16 Median Proportion of Lesions Evolving to PBH 0.17 0.08 0.04 Relative Risk (for Evolution to PBH) vs. placebo 0.74 0.63 p Value 0.074 0.011 New T1 gadolinium enhancing or new T2 lesions were defined as NL in the first on study MRI at month 2 Lesions that were hypointense and inactive at month 10 were PBH Relative Risk (RR) of NL evolution to PBH was analyzed using a general linear model with the error term from the Poisson distribution MN 166 MN 166 Reduction of Persistent Black Hole Reduction of Persistent Black Hole (PBH) Formation, a Sign of Axonal Loss (PBH) Formation, a Sign of Axonal Loss 45 MediciNova, Inc. 2009 Approx.

Safety Database: MN 221 has been tested in almost 300 subjects in the US and Europe to date. Subjects have had infusions with no clinically significant adverse events at: 16 micrograms/minute for up to 4 hours for a total of 3840 micrograms, and at lower doses for up to 24 hours 43 MediciNova, Inc. 2009 Brain volume changes are linked to axonal loss 44 MN 166 MN 166 Chronic Efficacy Chronic Efficacy Demonstrated: Effects on Brain Volume Demonstrated: Effects on Brain Volume 1.20 MediciNova, Inc. 2009 Reduction of Persistent Black Hole (PBH) Formation Parameter Treatment Groups Placebo 30 mg/day 60 mg/day # Patients w.

Other Potential Value from Other Potential Value from Avigen Avigen Transaction Transaction MediciNova, Inc. 2009 Study Design Randomized, placebo controlled, double blind, dose escalation study 23 subjects with mild to moderate stable asthma (FEV 1 60% predicted) at 4 sites Patients are randomized to one of four different treatment groups (25% of patients on placebo for every dose level) Each treatment sequence consist of placebo and escalating doses of MN 221 (0.35 g/min, 1.0 g/min, 3.5 g/min, 10 g/min, 16 g/min, 30 g/min, 60 g/min) for 15 minutes Primary endpoint mean change in FEV 1 (forced expiratory volume in 1 second) from baseline at 15 minutes (the end of the infusion) Outcome measures inferential statistics FEV 1 , pharmacokinetic (pk), safety and tolerability MN 221 CL 004 MN 221 CL 004 39 MediciNova, Inc. 2009 Eligible subjects were randomly assigned in a 1:1:1:1 ratio to 1 of 4 dose escalation treatment sequences: MN 221 CL 004: MN 221 CL 004: Dose Treatment Groups Dose Treatment Groups 40 Group A Group B Group C Group D Visit 2 Placebo 0.35 g/min for 15 minutes 0.35 g/min for 15 minutes 0.35 g/min for 15 minutes Visit 3 1.0 g/min for 15 minutes Placebo 1.0 g/min for 15 minutes 1.0 g/min for 15 minutes Visit 4 3.5 g/min for 15 minutes 3.5 g/min for 15 minutes Placebo 3.5 g/min for 15 minutes Visit 5 10 g/min for 15 minutes 10 g/min for 15 minutes 10 g/min for 15 minutes Placebo Visit 6 Placebo 16 g/min for 15 minutes 16 g/min for 15 minutes 16 g/min for 15 minutes Visit 7 30 g/min for 15 minutes Placebo 30 g/min for 15 minutes 30 g/min for 15 minutes Visit 8 60 g/min for 15 minutes 60 g/min for 15 minutes Placebo 60 g/min for 15 minutes MediciNova, Inc. 2009 Study Design Randomized, placebo controlled, single blind, dose rate escalation study 17 subjects with moderate to severe stable asthma (FEV 1 40%, but = 75% predicted) at 4 sites Doses: 16 g/min for 15 minutes followed by 8 g/min for 105 minutes (2 hour infusion with a total dose of 1,080 g) or placebo 30 g/min for 15 minutes followed by 15 g/min for 45 minutes (1 hour infusion with a total dose of 1,125 g) or placebo Outcome measures descriptive statistics only FEV 1 , pk, safety MN 221 CL 005 MN 221 CL 005 41 MediciNova, Inc. 2009 Study Design Randomized, placebo controlled, modified single blind, dose escalation study 29 patients with acute exacerbations of asthma (FEV 1 = 55% predicted) at 8 Emergency Department sites Doses: 16 g/min for 15 minutes (240 g) 30 g/min for 15 minutes (450 g) 16 g/min for 15 minutes; 8 g/min for 105 minutes (1,080 g) Patients received Standard of Care (SOC) treatment in addition to adjunctive treatment with MN 221 or placebo Outcome measures descriptive statistics only FEV 1 , pk, safety MN 221 CL 006 MN 221 CL 006 42 MediciNova, Inc. 2009 MN 221 Safety Summary MN 221 Safety Summary Phase II Study Safety Findings: No clinically significant cardiovascular, ECG, or vital sign changes, or other safety concerns, observed at doses up to 3840 micrograms in 4 hours.

Effective share issuance at the market: MediciNova effectively will have raised capital without payment of offering expenses and underwriting commissions, which are typically 15% in many small/micro cap companies. A conversion price of $6.80 and a 15% average discount yields savings of approximately $1.02 per MediciNova share. Once again, assuming 100% of Avigen s shareholders elect to receive convertible notes and convert such notes, this could represent a savings of approximately $6.0 million from a marketed offering of MediciNova shares.

Assuming that average daily volume of MediciNova s shares traded increases commensurately, the range of potential investors would be expected to expand with the increased liquidity and market capitalization. Using the conversion price of $6.80 and assuming 100% conversion into MediciNova shares, MediciNova s post transaction market capitalization would have been approximately $119 million as of 8/19/2009.

MediciNova, Inc. 2009 36 MN 221 (Exacerbations of Asthma/COPD Exacerbations): Proven mechanism of action Highly selective with improved safety profile vs. standard of care Positive Phase II efficacy and safety data for Acute Exacerbations of Asthma Phase II study ongoing for Acute Exacerbations of Asthma MN 166 (Multiple Sclerosis): Both chronic and acute efficacy have been demonstrated in clinical studies completed to date MediciNova seeking a partner to advance the clinical development of MN 166 Enhanced value with anticipated addition of Avigen s AV 411 data package Minimized Burn Rate: Annual burn rate reduced compared to previous years as a result of focus on MN 166 and MN 221 development programs ~$40.7 million net Cash, Cash Equivalents and Marketable Securities as of 6/30/09 Investment Highlights Investment Highlights Addendum: Addendum: Additional Information Avigen Transaction MN 221 Data MN 166 Data MediciNova, Inc. 2009 38 Other potential benefits that may accrue should Avigen s shareholders elect to take convertible notes as merger consideration and subsequently convert these notes: Increased liquidity in the U.S. markets: Presuming that 100% of Avigen s shareholders elect to receive convertible notes and convert such notes, MediciNova s publicly held shares would increase by approximately 45%.

MN 221: Expanded Indication MN 221: Expanded Indication COPD Exacerbations COPD Exacerbations COPD patients are generally more ill than asthmatics with overall higher hospitalizations and mortality. Source: CDC, CDC COPD surveillance in U.S. 2000; US Census; American Lung Association website COPD Discharged Hospitalized 72% 28% 1,900 Asthma 52% 48% 1,500 Hospitalization rates amongst Asthma and COPD patients Thousands 726 532 MediciNova, Inc. 2009 32 MN 221 MN 221 Phase II Program 2007 2007 2008 2008 2009 2009 2010 2010 1H 1H 2H 2H 1H 1H 2H 2H 1H 1H 2H 2H 1H 1H 2H 2H Acute Asthma CL 004 Dose Escalation CL 005 Prolonged Infusion CL 006 Single Blind CL 007 Double Blind * COPD Exacerbations To be determined MN 221 Phase II Clinical MN 221 Phase II Clinical Development Timeline Development Timeline Note: Development plans / timelines for MN 221 are subject to change *Anticipated completion dates based on current projections MediciNova, Inc. 2009 33 Commercially Attractive Commercially Attractive Diversified Portfolio Diversified Portfolio MediciNova, Inc. 2009 34 Dual Listing: MNOV (NasdaqGM) 4875 (Osaka Hercules) Net Cash, Cash Equivalents and Marketable Securities: ~$40.7 million as of 6/30/09 Market cap as of 8/19/09: ~$85.5 million Shares outstanding: ~12 million Key Financials Key Financials MediciNova, Inc. 2009 35 Leadership Years Experience Background Yuichi Iwaki, MD, PhD Yuichi Iwaki, MD, PhD CEO President 33 Professor at USC, formerly Professor at University of Pittsburgh; Advisor to JAFCO, Tanabe Shintaro Shintaro Asako, CPA Asako , CPA , CPA Chief Financial Officer 11 KPMG USA (Audit), Arthur Andersen USA Masatsune Masatsune Okajima, CMA Okajima , CMA , CMA VP, Head of Japanese Office 17 Daiwa Securities SMBC, Sumitomo Capital Securities, Sumitomo Bank Management Team with Management Team with Global Experience Global Experience Alan Dunton, MD, PhD Alan Dunton , MD, PhD Dunton , MD, PhD , MD, PhD Key Consultant Board Director 20+ CEO of Panacos Metaphore; President of the Janssen Research Foundation, a J J company.

MN 221 CL 007 MN 221 CL 007 30 MediciNova, Inc. 2009 31 Exacerbations of Chronic Obstructive Pulmonary Disease (COPD) are a sustained worsening of the patient's condition, from the stable state and beyond normal day to day variations, that is acute in onset. An estimated 10 million adults with COPD in the US 1.5 million hospital emergency department visits 726,000 hospitalizations 119,000 deaths The direct/indirect costs related to COPD amounted to approximately $42.6 billion in 2007.

This may result in fewer cardiovascular side effects which are common with the current standard of care. 2) Improved Safety 2) Improved Safety MediciNova, Inc. 2009 23 Approximately 25% of patients who present to the emergency department with an acute exacerbation of asthma have to be hospitalized. Based on clinical data obtained in our first emergency department based study, patients treated with MN 221 in the emergency department may lower the hospitalization rate. 3) Reduced 3) Reduced Health Care Health Care Expenses Expenses MediciNova, Inc. 2009 24 Human Human Adrenergic Receptor Adrenergic Receptor Selectivity Selectivity Test Drug 1 IC 50 (M) 2 IC 50 (M) 2 Adrenoceptor Selectivity (IC 50 for 1 / IC 50 for 2 ) Levalbuterol 7.40E 06 1.40E 06 5.3 Albuterol 9.40E 06 1.60E 06 5.9 Terbutaline 6.00E 05 6.50E 06 9.2 MN 221 5.90E 06 1.40E 07 42.4 MediciNova, Inc. 2009 Effect on Heart rate: Effect on Heart rate: Combination of MN 221 Albuterol Combination of MN 221 Albuterol in Dogs in Dogs 25 MediciNova, Inc. 2009 MN 221 Phase II Study Designs MN 221 Phase II Study Designs 26 CL 004 CL 005 CL 006 CL 007 Type of Asthma Mild to moderate Moderate to Severe Acute Exacerbations Acute Exacerbations FEV 1 (Entry Criteria) FEV 1 60% 75% FEV 1 40% FEV 1 55% FEV 1 50% Number Patients 23 17 29 200 Number Sites 4 4 8 ~45 Doses Tested compared to Placebo 5.25, 15, 52.5, 150, 240, 450, 900 g over 15 min 1080 g over 2 hr; 1,125 g over 1 hr 240, 450 g over 15 min; 1080 g over 2 hr 1200 g over 1 hr MN 221 CL 004: MN 221 CL 004: Mean Change in FEV Mean Change in FEV 1 1 (at 15 min.) (at 15 min.) Baseline: 77.83% 77.67% 76.78% 81.60% 74.78% 75.78% 78.07% 79.78% MediciNova, Inc. 2009 27 MediciNova, Inc. 2009 MN 221 CL 005: MN 221 CL 005: Mean Change in FEV Mean Change in FEV 1 1 (at end of infusion) (at end of infusion) 28 Baseline: 64.57% Baseline: 69.35% Mean: Mean: 82.04% 82.04% Mean: Mean: 81.47% 81.47% Baseline: 68.64% Baseline: 68.64% MediciNova, Inc. 2009 MN 221 CL 006 MN 221 CL 006 Hospitalization Rate by Treatment Group Hospitalization Rate by Treatment Group 29 MN 221 reduced the hospitalization rate by 45% MediciNova, Inc. 2009 Study Design Randomized, placebo controlled, double blind, multi center clinical trial 200 patients with severe, acute exacerbations of asthma (FEV 1 50% predicted) at ~45 Emergency Department sites in North America, Australia, and New Zealand Dose: 40 g/min for 15 minutes;13.3 g/min for 45 minutes (1,200 g) Patients will receive Standard of Care (SOC) treatment in addition to adjunctive treatment with MN 221 or placebo Primary efficacy endpoint will be improvement in FEV 1 (% predicted) at 5 hours The study is designed to have 80% power to detect a treatment difference of 5 percentage points in FEV 1 (% predicted) when comparing MN 221 + SOC to Placebo + SOC at a two sided level of 0.05.

MN 221 s intravenous formulation allows MN 221 to access the beta 2 receptors in the lungs without having to pass through the constricted airways. 1) Improved Efficacy 1) Improved Efficacy MediciNova, Inc. 2009 22 MN 221 has a higher selectivity for the beta 2 receptors than the beta 1 receptors as compared with other beta 2 agonists. MN 221 is only a partial agonist for the beta 1 receptor.

Improved Efficacy 2. Improved Safety 3. Reduced Health Care Expenses MN 221: A New Approach to Treating MN 221: A New Approach to Treating Acute Exacerbations of Asthma Acute Exacerbations of Asthma MediciNova, Inc. 2009 21 MN 221 may improve efficacy over current standard of care due to its route of administration. Currently patients who are struggling to breathe are given beta agonists in an inhaled formulation.

Second generation dual target leads. Additional Value from Avigen Additional Value from Avigen Deal Deal MediciNova, Inc. 2009 18 MN 166: NEXT STEPS MN 166: NEXT STEPS Seek Partnership for Further Development: MediciNova s strategic objective for MN 166 is to secure a partner to advance the clinical development of MN 166. MediciNova, Inc. 2009 19 Definition: Long lasting and severe asthma episode that is not responsive to initial bronchodilator or corticosteroid therapy Market Opportunity*: Approximately 2 million annual emergency room visits and 500,000 annual hospitalizations in the US Approximately 2.7 million annual emergency room visits and 560,000 annual hospitalizations in UK/Spain/Germany/France/Italy Potential $1 Billion+ combined market opportunity worldwide (Acute Asthma COPD exacerbations) Current Standard of Care (SOC): Beta agonists Inhaled Anticholinergics (ipratropium bromide) Inhaled Corticosteroids (66 77% of patients) IV or oral *Source: National Center for Health Statistics / CDC, WHO website, Core Health indicators Acute Exacerbations of Asthma Acute Exacerbations of Asthma MediciNova, Inc. 2009 20 MN 221: A novel, highly selective 2 adrenergic receptor agonist; licensed from Kissei Pharmaceutical in 2004 Three Potential Advantages over current therapy 1.

AV 411 preclinical data expected to support clinical package for MN 166. Open IND for ibudilast. AV 411 trial supports MN 166 dosing up to 100 milligrams (mg) versus the maximum dosing of 60 mg in the Phase 2 trial for MN 166. Expected time savings of six to twelve months. Analog compounds behind ibudilast. First generation development candidate: AV1013.

New Lesions at Month 2 72 64 56 Total Number New Lesions in all Patients 426 338 315 Total Number of Persistent Black Holes 98 58 47 Proportion of Lesions Evolving to PBH 0.23 0.17 0.14 p Value 0.036 0.004 New T1 gadolinium enhancing or new T2 lesions were defined as NL in the first on study MRI at month 2 Lesions that were hypointense and inactive at month 10 were PBH Relative Risk (RR) of NL evolution to PBH was analyzed using a general linear model with the error term from the Poisson distribution Reduction of Persistent Black Hole Reduction of Persistent Black Hole (PBH) Formation (PBH) Formation 14 MediciNova, Inc. 2009 TREATMENT Time Period Placebo to Active ( N=100 ) Active Drug [30 mg (N=94), 60 mg (N=98)] 2 Years 21/100 (21%) 20/194 (10.4%) Disability Progression is defined as a sustained increase in EDSS (increase in EDSS 1 maintained for four consecutive months) Sustained Disability Progression Sustained Disability Progression P Value: 0.026 15 MediciNova, Inc. 2009 16 Acute Efficacy Demonstrated: Acute Efficacy Demonstrated: Time to First Relapse Time to First Relapse Median 401 days Median 244 days P Value: 0.044 MediciNova, Inc. 2009 17 AV 411 Package Both AV 411 and MN 166 are derived from Ibudilast.

Completed Clinical Study: Completed Clinical Study: MN 166 CL 001 MN 166 CL 001 11 MediciNova, Inc. 2009 MN 166 Effects Outcomes Related to Disease Progression in RRMS Patients Clinical and MRI Outcomes: Indicative of Potential Neuroprotective Effect: 1. Reduced Brain Volume Loss 2. Reduced Conversion of Acute Lesions to Persistent Black Holes 3. Sustained disability progression was significantly less likely (~50%) Acute Clinical Benefit: Prolong time to relapse (by 127 days.) MN 166 was very well tolerated in Phase II study: 89% (264 of 297) of subjects completed the first 12 months of the study 82.5% (245 of 297) of subjects completed the full 24 months of the study GI adverse effects as a group and depression were the only adverse events to occur more frequently in MN 166 treated than in placebo treated subjects 12 P Value: 0.044 P Value: 0.030 MN 166 Targets Primarily MN 166 Targets Primarily Chronic Aspects of MS Chronic Aspects of MS P Value: 0.026 P Value: 0.004 MediciNova, Inc. 2009 N=71 1.59 Chronic Efficacy Demonstrated: Chronic Efficacy Demonstrated: Effects on Brain Volume Effects on Brain Volume N=70 1.79 N=34 2.08 N=45 2.12 Percent Brain Volume Reduction Percent Brain Volume Reduction (0 24 months) Brain volume loss was significantly less (p=0.030) in patients receiving 60 mg per day of MN 166 for 24 months compared to the other treatment groups 13 MediciNova, Inc. 2009 Parameter Treatment Groups Placebo 30 mg/day 60 mg/day Number Patients w.

There is no cure for the disease. Multiple Sclerosis Market: Over $8 billion worldwide sales in 2008* Current Standard of Care: Beta interferons (Rebif, Avonex, Betaserone), Copaxone , Tysabri Administered either by intramuscular or subcutaneous injection or infusion MN 166 for Multiple Sclerosis: Oral Administration Anti inflammatory and neuroprotective propreties Multiple Sclerosis Multiple Sclerosis *Source: Individual annual reports of leading MS companies, 2008 MediciNova, Inc. 2009 Placebo controlled, randomized, double blind Phase II study: Year 1 0, 10 mg three times a day (tid), 20 mg tid Year 2 10 mg tid, 20 mg tid n ~ 100 MS patients/group 25 sites in Serbia, Ukraine, Belarus, Bulgaria and Romania Key inclusion criteria: Males or females aged 18 to 55 years, with relapsing remitting (RR) and/or secondary progressive (SP) Multiple Sclerosis with continued relapses; A definite diagnosis of relapsing MS using the new International Committee recommendations (MacDonald Criteria); One MRI scan taken two weeks prior to treatment start using a standardized MRI protocol with at least one Gd enhancing lesion; An Expanded Disability Status Scale (EDSS) score of 5.5 or less at the screening and baseline visits.

Summary Securities Ownership Review (Fully Diluted Basis) Pre Transaction Pro Forma Shares Outstanding Post Transaction (1) Consideration Shares All Cash 50% Cash 50% Conv. Notes (2) (3) 100% Conv. Notes (2) (3) Common Stock Equivalents MediciNova Stockholders 12,048,003 12,048,003 12,048,003 12,048,003 Avigen Stockholders 2,717,712 5,435,424 MediciNova Exercisable Options 1,711,350 1,711,350 1,711,350 1,711,350 13,759,353 13,759,353 16,477,065 19,194,777 Ownership % MediciNova Stockholders 87.6% 87.6% 73.1% 62.8% Avigen Stockholders 0.0% 0.0% 16.5% 28.3% MediciNova Exercisable Options 12.4% 12.4% 10.4% 8.9% 100.0% 100.0% 100.0% 100.0% MediciNova, Inc. 2009 10 Definition: Multiple sclerosis (MS) is an inflammatory demyelinating disease of the central nervous system (CNS), affecting approximately 500,000 people in the United States and 2 million people worldwide.

Sources of information: SEC Edgar Filings Pro Forma Stockholder Review Pro Forma Stockholder Review This pro forma ownership review is presented for illustrative purposes only and does not indicate actual ownership of MediciNova shares at any past, present, of future date. Actual ownership of MediciNova shares will depend on a variety of factors, including the actual amounts of the First Payment Consideration and Second Payment Consideration and the rounding of fractional shares set forth in the indenture governing the convertible notes.

(1) Assumes first payment consideration and second payment consideration aggregate $37.0 million and are both paid at closing and that MediciNova issues no shares or options from August 20, 2009 through the first conversion date of the convertible notes. (2) Assumes the convertible notes convert to MediciNova shares at $6.80. (3) Assumes all convertible notes are converted into MediciNova shares on the first monthly conversion date.

Approval Conditions Requires affirmative vote of a majority of outstanding stock entitled to vote of: MediciNova for the approval of the issuance of the convertible notes; and Avigen for the adoption of the Merger Agreement. Other Provisions Customary conditions to closing and termination rights. No break up fees to either party; however, if Avigen board changes its recommendation and the merger is not approved, MediciNova entitled to receive 50% of out of pocket expenses up to $500,000.

MediciNova, Inc. 2009 Avigen Avigen Transaction Overview Transaction Overview 8 Convertible Notes Consideration 18 month maturity from the date of closing of merger (no early cash redemption). Principal from the notes will be held in a trust account with principal invested in certain approved investment options. The notes can be converted on a monthly basis into common shares of MediciNova at an initial conversion price equal to $6.80.

If the milestone payment has not occurred and the Parkinson s product (as defined in the Genzyme Agreement) is sold by MediciNova within 20 months of the effective time of the merger, 50% of the net proceeds from such sale received within such 20 month period. Certain amounts remaining in a plan trust created by Avigen upon satisfaction of certain severance and benefits payments.

This holdback amount is being held for any adjustments to certain Avigen defined expenses, marketable security risk, sub tenant risk, and other liabilities in excess of amounts agreed by the parties. Contingent Payment Rights Provides for payment of certain assets to Avigen shareholders on a pro rata basis: $6.0 million milestone payment from Genzyme Corporation if such payment is received within 20 months of effective time of merger.

MediciNova, Inc. 2009 Avigen Avigen Transaction Overview Transaction Overview 7 Merger Consideration Each Avigen stockholder will have the option of receiving their pro rata allocation of cash or convertible notes aggregating approximately $37.0 million, subject to potential upward and downward adjustments as set forth in the merger agreement: First payment consideration of approximately $35.5 million; and Second payment consideration of approximately $1.5 million payable on June 30, 2010.

Clinical data with higher dose of ibudilast, an open IND and obtaining control of the AV 411 use patent are expected to enhance partnering potential and shorten the time to approval. Avigen s significant cash balance represents a potential financing opportunity with MediciNova potentially deriving proceeds of up to $37 million, assuming some or all of Avigen s stockholders elect to receive MediciNova convertible notes in the transaction and subsequently convert those notes.

Avigen Avigen Transaction Overview Transaction Overview 6 MediciNova, Inc. 2009 Transaction Rationale Signed Definitive Merger Agreement with Avigen, Inc. on 8/20/2009. Following the completion of the transaction, Avigen will become a wholly owned subsidiary of MediciNova. Anticipated closing will be 4Q, 2009. AV 411 (ibudilast) preclinical materials can be used as support for the development pathway for MN 166 Anticipated cost savings of up to ~$7.0 million for MediciNova to reproduce data.

Continue internal development of compound towards commercialization 2. Seek partnership for further development of compound Business Model: Business Model: Return On Investment Return On Investment MediciNova intends to pursue further development of MN 221 independently in the United States; however, following our completion of the Phase II clinical trial of MN 166 for the treatment of MS, we are not planning to pursue any further significant clinical development of MN 166 until we secure a strategic collaboration to further development.

MediciNova, Inc. *Source: Individual annual reports of leading MS companies, 2008 MNOV Headquarters: San Diego, CA Key Financials: Signed Definitive Merger Agreement w/ Avigen, Inc. on 8/20/2009; anticipated closing 4Q09 Dual listed company on NasdaqGM and Osaka Securities Exchange Hercules ~$40.7 million net Cash, Cash Equivalents and Marketable Securities as of 6/30/2009 ~$85.5 million Market Cap (NasdaqGM) as of 8/19/09 MediciNova, Inc. 2009 5 In License: Novel, small molecule product candidates with significant clinical or preclinical data packages and attractive market opportunities Conduct Proof of Concept Clinical Trials: Conduct Phase I and Phase II clinical trials to demonstrate safety and efficacy of compound Two Pathways Towards ROI After Phase II: 1.

Investors and security holders will be able to obtain free copies of any documents filed with the SEC by MediciNova, Inc. and Avigen, Inc. through the website maintained by the SEC at http://www.sec.gov. MediciNova, Inc. 2009 4 Development Company Focused on Differentiated Product Candidates Unique access to differentiated, potentially high value assets primarily from Japanese alliances New Approaches to Treat Serious Medical Conditions: MN 221: Intravenous (IV) acute asthma and COPD candidate Potential $1 Billion+ combined market opportunity worldwide MN 166: oral multiple sclerosis candidate In 2008, over $8B in worldwide MS therapeutic sales* A diversified portfolio consisting of six additional compounds Corporate Overview: Corporate Overview: MediciNova, Inc.

This material is not a substitute for the registration statement/prospectus/proxy statement MediciNova, Inc. and Avigen, Inc. will file with the SEC or any other documents that the parties may file with the SEC and send to their respective shareholders in connection with the transaction. INVESTORS AND SECURITY HOLDERS OF AVIGEN, INC. ARE URGED TO READ ANY SUCH DOCUMENTS FILED WITH THE SEC CAREFULLY IN THEIR ENTIRETY WHEN THEY BECOME AVAILABLE BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE TRANSACTION.

Undue reliance should not be placed on these forward looking statements, which speak only as of the date hereof. MediciNova disclaims any intent or obligation to revise or update these forward looking statements. Forward Looking Statements Forward Looking Statements MediciNova, Inc. 2009 This communication does not constitute an offer to sell or the solicitation of an offer to buy any securities or a solicitation of any vote or approval.

These forward looking statements may be preceded by, followed by or otherwise include the words believes, expects, anticipates, intends, estimates, projects, can, could, may, would, or similar expressions. Actual results or events may differ materially from those expressed or implied in any forward looking statements due to various factors, including the risks and uncertainties inherent in clinical trials and product development and commercialization, such as the uncertainty in results of clinical trials for product candidates, the uncertainty of whether the results of clinical trials will be predictive of results in later stages of product development, the risk of delays or failure to obtain or maintain regulatory approval, the risk of failure of the third parties upon whom MediciNova relies to conduct its clinical trials and manufacture its product candidates to perform as expected, the risk of increased cost and delays due to delays in the commencement, enrollment, completion or analysis of clinical trials or significant issues regarding the adequacy of clinical trial designs or the execution of clinical trials and the timing, cost and design of future clinical trials and research activities; the timing of expected filings with the FDA; MediciNova s failure to execute strategic plans or strategies successfully; MediciNova s collaborations with third parties; failure to complete the merger with Avigen, Inc. on a timely basis or at all; the availability of funds to complete product development plans and MediciNova s ability to raise sufficient capital when needed; intellectual property or contract rights; and the other risks and uncertainties described in MediciNova s filings with the Securities and Exchange Commission, including MediciNova s annual report on Form 10 K for the year ended December 31, 2008 and its subsequent periodic reports on Forms 10 Q and 8 K.

These forward looking statements include statements regarding MediciNova s clinical trials supporting safety and efficacy of product candidates and the potential novelty of such product candidates as treatments for disease, plans and objectives for clinical trials and product development, anticipated benefits of the merger with Avigen, Inc., value and benefits to stockholders from such transaction, strategies, future performance, financial condition, liquidity and capital resources.

MediciNova, Inc. 2009 Accelerating the global development and commercialization of innovative pharmaceuticals Exhibit 99.1 MediciNova, Inc. 2009 Statements in this presentation that are not historical in nature constitute forward looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995.