MediciNova, Inc. 2008 2 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

USC, Formerly Prof. Pitt; Advisor to JAFCO, Tanabe Director, Avigen, Inc. Richard Gammans, PhD, MBA Richard Gammans , PhD, MBA Gammans , PhD, MBA , PhD, MBA Chief Development Officer 30 Incara, Indevus, BMS Kenneth W. Locke, PhD Kenneth W. Locke, PhD Chief Scientific Officer 23 Tanabe Research Laboratories USA, Indevus, Hoechst Shintaro Shintaro Asako, CPA Asako , CPA , CPA Chief Financial Officer 9 KPMG USA (Audit), Arthur Andersen USA Masatsune Masatsune Okajima, CMA Okajima , CMA , CMA VP, Head of Japanese Office 16 Daiwa Securities SMBC, Sumitomo Capital Securities, Sumitomo Bank Management Team with Global Management Team with Global Experience Experience MediciNova, Inc. 2008 28 MN 221 (Status Asthmaticus): Proven mechanism of action Highly selective with improved safety profile vs. standard of care Low risk / high reward proposition Positive efficacy data Low development costs to market MN 166 (Multiple Sclerosis): Current treatment of MS represents significant unmet medical need Multi billion dollar market opportunity Both chronic and acute efficacy have been demonstrated in clinical studies Robust pipeline Six compounds with applications in multiple disease areas Investment Highlights Investment Highlights

MN 166 treatment at 30 mg per day resulted in a trend toward reducing evolution to PBH (p=0.074). Loss of brain volume and development of PBHs on MRI have been shown to correlate with clinical progression and disability in MS patients. Reduction of Persistent Black Hole (PBH) Reduction of Persistent Black Hole (PBH) Formation, a Sign of Axonal Loss Formation, a Sign of Axonal Loss MediciNova, Inc. 2008 22 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. 2008 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 Safety Comparison with Other Safety Comparison with Other Oral Agents Oral Agents 23 MediciNova, Inc. 2008 24 Commercially Attractive Commercially Attractive Diversified Portfolio Diversified Portfolio MediciNova, Inc. 2008 25 MN 221 for Status Asthmaticus Single blind Phase IIb study to test efficacy commencement date: 1H 08 Results as early as 2H 08 Double blind Phase IIb study to test efficacy commencement date: 2H 08 Results as early as 2H 09 Second Phase IIa study for extended dosing commencement date: 1H 08 Results as early as 2H 08 MN 166 for Multiple Sclerosis Announced Two Year Phase II results April 7, 2008 Pursue corporate partnership to further development Medicinova is constantly evaluating opportunities to partner MN 166 and other product candidates Near Term Clinical Near Term Clinical Milestones Milestones MediciNova, Inc. 2008 26 Dual Listing: MNOV (NasdaqGM), December 2006 4875 (Osaka Hercules), February 2005 Limited liquidity due to low float Cash: $70.6 M as of 12/31/07 Market cap as of 4/15/08: ~$49.6 M Shares outstanding: 11.9 M Key Financials Key Financials MediciNova, Inc. 2008 27 Leadership Years Experience Background Yuichi Iwaki, MD, PhD Yuichi Iwaki, MD, PhD CEO President 32 Prof.

New Lesions at Month 2 72 64 56 Mean Proportion of Lesions Evolving to PBH 0.24 0.20 0.16 Relative Risk (for Evolution to PBH) vs. placebo 0.74 0.63 p Value 0.074 0.011 MN 166 treatment at 60 mg per day significantly reduced the relative risk for conversion of new inflammatory lesions identified at month two to Persistent Black Holes (PBH), an MRI indicator of neuronal loss, eight months later at month ten by 37 percent (p=0.011); such lesions that remain unchanged for eight months are considered PBHs as compared to transient inflammatory lesions that are more closely associated with relapses.

Current Clinical Studies: MN Current Clinical Studies: MN 166 CL 001 166 CL 001 16 MediciNova, Inc. 2008 MN 166 Effects Outcomes Related to Disease Progression in RRMS Patients Clinical and MRI Outcomes: Prolong time to relapse (by 127 days.) Sustained disability progression was significantly less likely (~50%) Reduced Brain Volume Loss Reduced Conversation of Acute Lesions to Persistent Black Holes Mechanisms of Action Stimulates Neurotrophic Growth Factor Release Inhibits nitric oxide and reactive oxygen species production Inhibits Th1 cytokine production (IFN , TNF , IL 1 , IL 6) Pilot studies found reduced relapse rate and Th1 Th2 cytokine shift Phosphodiesterase IV and Leukotriene inhibitor 17 P Value: 0.044 P Value: 0.030 MN 166 MN 166 Targets Targets Primarily Primarily Chronic Chronic Aspects Aspects of of MS MS P Value: 0.026 P Value: 0.011 MediciNova, Inc. 2008 18 Acute Efficacy Demonstrated: Acute Efficacy Demonstrated: Time to First Relapse Time to First Relapse MediciNova, Inc. 2008 TREATMENT Time Period Placebo to Active ( N=100 ) 30 mg (N=94) 60 mg (N=98) 1 Year 8 (8.0%) 5 (5.3%) 4 (4.1%) 2 Years 8/51 (15.7%) 13/49 (26.5%) 10 (10.6%) 10 (10.2%) 21/100 (21%) 20/194 (10.4%) p=0.0264 19 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 MediciNova, Inc. 2008 20 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 MediciNova, Inc. 2008 21 Reduction of Persistent Blackion Parameter Treatment Groups Placebo 30 mg/day 60 mg/day # Patients w.

Proven mechanism of action ( 2 adrenergic agonist) 2. Rapid, reliable IV delivery (vs. inhaled / nebulized) 3. Safer (greater selectivity = fewer cardiovascular SE) 8 Competitive Advantages of Competitive Advantages of MN 221 MN 221 MediciNova, Inc. 2008 9 Phase IIa study design Randomized, placebo controlled, double blind, sequential dose escalation 23 subjects with mild to moderate asthma Primary objective To determine the efficacy of a single 15 minute treatment with intravenous MN 221 Secondary objective To determine the MTD (Maximum Tolerated Dose) Primary endpoint met in Phase IIa study completed October 2007 Achieved statistical significance in its primary endpoint of mean change in FEV1 from baseline at 15 minutes at doses of 3.5, 10, 16, and 30 micrograms/min of MN 221 compared to placebo No clinically significant cardiovascular, ECG or vital sign changes, or any other safety concerns observed at any dose tested 60 micrograms/min x 15 min (900 mcg) dose a possible MTD of MN 221 MN 221: Positive Phase IIa data MN 221: Positive Phase IIa data MediciNova, Inc. 2008 Change from Pre Infusion FEV1 at 15 min (ITT) Placebo .35 ug/min 1.0 ug/min 3.5 ug/min 10 ug/min 16 ug/min 30 ug/min MN 221 CL 002: Primary MN 221 CL 002: Primary Efficacy Variable Efficacy Variable 10 MediciNova, Inc. 2008 MN 221: Safety MN 221: Safety Phase IIa Safety Findings: No clinically significant cardiovascular, ECG or vital sign changes, or any other safety concerns observed at doses up to 30 micrograms/minute for 15 minutes or any time point thereafter 60 micrograms/minute infusion improved FEV1 significantly ( p 0.0001 ) without clinically significant cardiovascular, ECG or vital sign changes; however, the safety trend led us to believe that this is a possible MTD and higher doses should not be tested Safety Database: MN 221 has been tested in over 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 and at lower doses for up to 24 hours 11 MediciNova, Inc. 2008 Commence two Phase IIb studies to test efficacy of MN 221 in status asthmaticus patients in the emergency room Single Blind (~32 patients) Anticipated commencement date: 1H 08 Results expected as early as 2H 08 Double Blind (~200 patients) Anticipated commencement date: 2H 08 Results expected as early as 2H 09 Commence second Phase IIa study in stable asthmatic patients (~20 patients) for extended dosing (4 hour infusion) Anticipated commencement date: 1H 08 Results expected as early as 2H 08 MN 221: Next Steps MN 221: Next Steps 12 MediciNova, Inc. 2008 13 MN 166 Overview MN 166 Overview Multiple Sclerosis Autoimmune disease Progressive loss of neuromuscular function Relapsing forms Progressive forms Damage to myelin sheath Damage to neuronal axon MediciNova, Inc. 2008 14 Multiple Sclerosis Market: Approximately $7.2 B worldwide sales in 2006* Current Standard of Care: Beta interferons, Copaxone , Tysabri Administered either by intramuscular or subcutaneous injection or infusion MN 166: Anti inflammatory and neuroprotective properties in vitro and in vivo Stimulates Th2 cytokine production and neurotrophic factor release Cerebrovasodilator Inhibits leukotrienes, phosphodiesterases, Th1 cytokine production, nitric oxide and reactive oxygen species production Demonstrated effects on brain volume Targets both primarily chronic aspects of multiple sclerosis Oral administration MN 166 Overview MN 166 Overview *Source: MedAdNews, June 2007 MediciNova, Inc. 2008 15 Description Efficacy (relapse rate) Current agents offer only 30 50% relapse reduction Neutralizing antibodies can diminish efficacy over time Most patients ultimately progress; neurodegeneration leads to functional disability AEs including flu like symptoms SAEs Rare but fatal PML with Tysabri Safety issues with pipeline drugs Safety/ tolerability Injections daily or weekly Infusions monthly Administration Increasing interest in combination therapies given sub optimal efficacy with current core agents Black box on combination with Tysabri, REMS program Combination Demonstrated neuroprotection, that is, reduction in disease progression, would be groundbreaking Historically, anti inflammatory agents have shown little impact on disease progression Axonal Protection There Are Substantial There Are Substantial Unmet Needs in MS Unmet Needs in MS MediciNova, Inc. 2008 Placebo controlled, randomized, double blind Phase II study: Year 1 0, 10 mg 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 EDSS score of 5.5 or less at the screening and baseline visits.

MediciNova, Inc. *Source: MedAdNews, June 2007 MediciNova, Inc. 2008 4 In License: Product candidates with significant clinical or preclinical data Conduct Proof of Concept Clinical Trials: Conduct Phase I and Phase II clinical trials to demonstrate efficacy of compound Two Pathways Towards ROI After Phase II: Continue internal development of compound towards commercialization Seek partnership for further development of compound Business Model: Business Model: Return On Investment Return On Investment MediciNova, Inc. 2008 5 NDA MN 221 Development Plan MN 221 Development Plan Note: Development plans / timelines for MN 221 are subject to change Anticipated commencement and completion dates based on current projections We also plan to conduct an advanced clinical trial of MN 221 in pediatric patients with status asthmaticus; however, we have not yet determined whether this clinical trial will be initiated in conjunction with the other planned Phase III clinical trials or after NDA submission Filing as early as 2H 10 MediciNova, Inc. 2008 6 Definition: Long lasting and severe asthma episode that is not responsive to initial bronchodilator or corticosteroid therapy MN 221: Novel, highly selective 2 adrenergic receptor agonist Greater selectivity Partial agonist for 1 receptor in the heart Full agonist for 2 receptor in the lungs Improved safety (fewer cardiovascular side effects) compared to older agonists IV formulation for acute hospital use Reliable and rapid delivery Positive Phase IIa results reported in October 2007 MN 221: A New Approach to MN 221: A New Approach to Treating Status Asthmaticus Treating Status Asthmaticus MediciNova, Inc. 2008 7 Market Opportunity: Approximately 1.9 million emergency room visits in the US each year 500,000 hospitalizations Approximately 4,000 deaths annually in the US Potential $500 M market opportunity for MediciNova Current Standard of Care: Beta agonists (all patients) Inhaled or nebulized Corticosteroids (66 77% of patients) IV or oral *Source: National Center for Health Statistics / CDC MN 221: Market Opportunity MN 221: Market Opportunity MediciNova, Inc. 2008 1.

Undue reliance should not be placed on these forward looking statements, which speak only as of the date hereof. We disclaim any intent or obligation to revise or update these forward looking statements. Forward Looking Statements Forward Looking Statements MediciNova, Inc. 2008 3 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: IV Status Asthmaticus candidate Potential $500 M US opportunity for MediciNova MN 166: Oral Multiple Sclerosis candidate In 2006, approximately $7.2 B in worldwide MS therapeutic sales* Diverse Pipeline: Six compounds with applications in multiple disease areas Corporate Overview: Corporate Overview: MediciNova, Inc.

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, without limitation, 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 we rely to conduct our clinical trials and manufacture our 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; our failure to execute strategic plans or strategies successfully; our collaborations with third parties; the availability of funds to complete product development plans and our ability to raise sufficient capital when needed; intellectual property or contract rights; and the other risks and uncertainties described in our filings with the Securities and Exchange Commission, including our annual report on Form 10 K for the year ended December 31, 2007.

Accelerating the global development and commercialization of innovative pharmaceuticals April 2008 Exhibit 99.1 MediciNova, Inc. 2008 2 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. These forward looking statements include, without limitation, statements regarding our 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, strategies, future performance, financial condition, liquidity and capital resources.