Forward-Looking Statements Certain statements set forth in this presentation constitute "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, but

Richard Pops Chief Executive Officer

Alkermes: Advancing Key Business Priorities in 2022 January 2022 40th Annual J.P. Morgan Healthcare Conference Exhibit 99.1

Forward-Looking Statements Certain

statements set forth in this presentation constitute "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, as amended, including, but not limited to, statements concerning: the

company's expectations with respect to its current and future financial and operating performance, business plans or prospects, including expected commercial growth drivers and development opportunities, and execution against 2022 financial

expectations and long-term profitability goals; the potential therapeutic and commercial value of the company's marketed products and development candidates, including nemvaleukin alfa ("nemvaleukin") as a cancer immunotherapy when

used as monotherapy or in combination and whether delivered intravenously or subcutaneously, and its potential utility across a range of tumor types, dosing options and potential combinations with other targeted therapies; expectations regarding

patent life for nemvaleukin; expectations regarding the effectiveness and potential of the company's research and development ("R&D") objective, approach and capabilities, including its molecule design and engineering

capabilities; timelines, plans and expectations for development activities relating to the company's development candidates, including (i) for nemvaleukin, planned and ongoing clinical studies in the ARTISTRY development program, including

plans to evaluate potential dosing flexibility, and plans to pursue strategic collaborations, (ii) for ALKS 1140, plans to advance the phase 1 program, (iii) for ALKS 2680, plans to complete IND-enabling activities and prepare for initiation of a

first-in-human study, and (iv) for the engineered cytokine program, plans to advance the IL-12 and IL-18 preclinical programs to key decision points; and expectations concerning commercial activities relating to the company's products,

including plans for the ongoing commercial launch of LYBALVI and the company's ability to leverage its existing commercial infrastructure. The company cautions that forward-looking statements are inherently uncertain. Actual performance

and results may differ materially from those expressed or implied in the forward-looking statements due to various risks, assumptions and uncertainties. These risks, assumptions and uncertainties include, among others: whether LYBALVI will be

commercialized successfully; the impacts of the ongoing COVID-19 pandemic and continued efforts to mitigate its spread on the company's business, results of operations or financial condition; the unfavorable outcome of litigation, including

so-called "Paragraph IV" litigation or other patent litigation which may lead to competition from generic drug manufacturers, or other disputes related to the company's products or products using the company's

proprietary technologies; clinical development activities may not be completed on time or at all; the results of the company's development activities may not be positive or predictive of real-world results, and preliminary data from ongoing

studies may not be predictive of future or final data from such studies, results of future studies or real-world results; the U.S. Food and Drug Administration ("FDA") or other regulatory authorities may not agree with the

company's regulatory approval strategies or components of the company's marketing applications, including clinical trial designs, conduct and methodologies, manufacturing processes and facilities, or the adequacy of the data or other

information included in the company's regulatory submissions to support their requirements for approval, and may make adverse decisions regarding the company's products; the company and its licensees may not be able to successfully

commercialize their products or support growth of revenue from such products; there may be a reduction in payment rate or reimbursement for the company's products or an increase in the company's financial obligations to governmental

payers; the company's products may prove difficult to manufacture, be precluded from commercialization by the proprietary rights of third parties, or have unintended side effects, adverse reactions or incidents of misuse; and those risks,

assumptions and uncertainties described under the heading "Risk Factors" in the company's Annual Report on Form 10-K for the year ended Dec. 31, 2020 and in subsequent filings made by the company with the U.S. Securities and

Exchange Commission ("SEC"), which are available on the SEC's website at www.sec.gov and on the company's website at www.alkermes.com in the "Investors-SEC filings" section. Existing and prospective

investors are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date hereof. Except as required by law, the company disclaims any intention or responsibility for updating or revising any

forward-looking statements contained in this presentation. Note Regarding Trademarks: The company and its affiliates are the owners of various U.S. federal trademark registrations ( ) and other trademarks (TM), including ARISTADA ,

ARISTADA INITIO , VIVITROL , and LYBALVI . VUMERITY is a registered trademark of Biogen MA Inc., used by Alkermes under license. Any other trademarks referred to in this presentation are the property of their respective owners.

Appearances of such other trademarks herein should not be construed as any indicator that their respective owners will not assert their rights thereto.

Focused on disciplined capital

allocation and optimized cost structure Restructured commercial organization to support launch of LYBALVI Initiated nemvaleukin alfa studies in mucosal melanoma and platinum-resistant ovarian cancer to support potential registration Initiated ALKS

1140 phase 1 first-in-human study Advanced ALKS 2680 into IND-enabling activities Development Pipeline Advance pipeline of neuroscience and oncology candidates LYBALVI : Approved and commercially launched ARISTADA : Drove TRx growth that

outpaced the market VIVITROL : Redefined alcohol dependence strategy to drive next phase of growth Commercial Grow commercial portfolio of proprietary products Three Strategic Priorities Grounded in Strong Culture of Responsibility

Profitability Drive long-term profitability Patient-focused ethos and strong commitment to corporate responsibility and governance

Focused on disciplined capital

allocation and optimized cost structure Restructured commercial organization to support launch of LYBALVI Continued Board of Directors refreshment efforts Appointed two new independent Directors Announced retirement of two longer-serving Directors

Initiated declassification of Board of Directors Initiated nemvaleukin alfa studies in mucosal melanoma and platinum-resistant ovarian cancer to support potential registration Initiated ALKS 1140 phase 1 FIH study Nominated ALKS 2680 and commenced

IND-enabling activities Development Pipeline LYBALVI : Approved and commercially launched ARISTADA : Drove TRx growth that outpaced the aLAI market VIVITROL : Advanced alcohol dependence strategy to drive next phase of growth

Commercial Execution 2021 Key Achievements Advanced Core Business Objectives Profitability Supported research, education and patient advocacy programs to benefit people affected by serious mental illness, addiction or cancer Introduced new

Diversity, Inclusion and Belonging employee resource groups Continued commitment to sustainability Patient-focused ethos and strong commitment to corporate responsibility and governance

Phase 1 Neurodegenerative and

neurologic disorders Neuroscience Oncology Pipeline of novel development candidates designed to target significant unmet needs Diversified Biopharmaceutical Company With Proven Drug Development and Commercialization Capabilities Licensed to and

commercialized by Biogen (royalty & manufacturing revenue) Phase 2/3 Advanced solid tumors Nemvaleukin Alfa IL-12 Discovery Advanced solid tumors ALKS 1140 ALKS 2680 Preclinical Narcolepsy Significant, diverse revenues with new growth

Current Growth Drivers

Commercial Growth Drivers

LYBALVI : Oral Treatment Option

for Adults With Schizophrenia or Bipolar I Disorder Once-daily, oral atypical antipsychotic composed of olanzapine, an established antipsychotic agent, and samidorphan, a new chemical entity Commercially launched in U.S. Q4 2021 Indicated for the

treatment of: Schizophrenia in adults Bipolar I disorder (BD-1) in adults Acute treatment of manic or mixed episodes as monotherapy and as adjunct to lithium or valproate Maintenance monotherapy treatment Boxed Warning: Elderly patients with

dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. LYBALVI is not approved for the treatment of patients with dementia-related psychosis. Full prescribing information may be found at

LYBALVI : Offers Proven Efficacy

With a Differentiated Weight Gain Profile in Adult Patients with Schizophrenia LYBALVI offers proven efficacy* and was associated with less weight gain versus olanzapine in patients with schizophrenia in the ENLIGHTEN-2 clinical trial** ENLIGHTEN-1:

LYBALVI demonstrated a statistically significant improvement in the change from baseline in PANSS total score versus placebo in patients with schizophrenia at week 4 ENLIGHTEN-2: LYBALVI was associated with less weight gain versus olanzapine

in patients with schizophrenia at week 24 *Inclusion of samidorphan in LYBALVI did not appear to negatively impact the efficacy of olanzapine. **Inclusion of samidorphan in LYBALVI appeared to result in less weight gain than was seen with

olanzapine alone.1 Increased weight was the most common adverse reaction in patients treated with LYBALVI in ENLIGHTEN-1 and ENLIGHTEN-2. Other common adverse reactions were somnolence, dry mouth and headache. Boxed Warning: Elderly patients

with dementia-related psychosis treated with antipsychotic drugs are at an increased risk of death. LYBALVI is not approved for the treatment of patients with dementia-related psychosis. Full prescribing information may be found at

www.lybalvi.com/lybalvi-prescribing-information.pdf 1Correll CU, Newcomer JW, Silverman B, et al. Effects of olanzapine combined with samidorphan on weight gain in schizophrenia: a 24-week phase 3 study. Am J Psychiatry. 2020.

doi.org/10.1176/appi.ajp.2020.19121279.

LYBALVI : Sophisticated

Commercial Presence in Psychiatry Creates Operating & Financial Leverage Commercial Support Infrastructure Marketing Managed markets Patient support services Commercial operations State and Federal policy efforts Commercial Field Organization

Psychiatry field sales organization calling on highly synergistic prescriber universe Hybrid Promotional Approach Increased reach and efficiency utilizing digital channels and virtual interactions

LYBALVI : Launch Targeting

Focused on Three Prescriber Characteristics Across Schizophrenia and BD-1 Alkermes field organization calls on focused healthcare provider universe, prioritized for high-potential prescribers of branded oral antipsychotics Prescribes olanzapine

Utilizes branded oral atypical antipsychotic products Initiates therapy Prescribes olanzapine Utilizes branded oral atypical antipsychotic products Initiates therapy Utilizes branded oral atypical antipsychotic products Prescribes olanzapine

LYBALVI : Commercial Launch Off

to Strong Start Prescription and Prescriber Growth by Week Post Launch Source: IQVIA NPA and IQVIA XPO 1 IQVIA reported TRxs (NPA Audit Nov'21 R12M). Unlike olanzapine, LYBALVI contains an opioid antagonist and is

contraindicated in persons using opioids. 2Due to data limitations, schizophrenia data includes schizoaffective disorder (for which LYBALVI is not indicated). 3 Branded market includes: LATUDA , REXULTI , VRAYLAR , CAPLYTA ,

FANAPT , SAPHRIS ~63M oral atypical antipsychotics TRx1 ~15M in schizophrenia/schizoaffective2 ~13M in bipolar I disorder ~8M TRx for olanzapine1 22% market share in schizophrenia 12% market share in bipolar I disorder ~5.7M branded oral

atypical antipsychotic TRx 1,3 U.S. Oral Atypical Antipsychotic Market * ** * Thanksgiving week 2021 ** Christmas week 2021

Commercial Growth Drivers

Schizophrenia With Dosing Flexibility Long-acting injectable (LAI) atypical antipsychotic indicated for the treatment of schizophrenia Novel molecular entity designed to address the real-world needs of patients and providers Ability to fully dose on

day one for up to two months with ARISTADA INITIO regimen* *ARISTADA INITIO + single 30 mg oral dose of aripiprazole replaces need for concomitant three weeks of oral aripiprazole for initiation of ARISTADA. The first ARISTADA dose may be

administered on the same day as ARISTADA INITIO or up to 10 days thereafter. Full prescribing information for ARISTADA, including Boxed Warning, may be found at www.aristada.com/downloadables/ARISTADA-PI.pdf

ARISTADA : Growth has Outpaced

the aLAI Market Inclusive of ARISTADA INITIO TTM (trailing 12 month) data include Q4'20 through Q3'21 net sales results. ARISTADA Net Sales ($M) Q3 2021 ARISTADA TRx MOT Growth Outpaced Market** **TRx Data: IQVIA NPA data

Q3'21; aLAI Market data inclusive of ARISTADA; MOT: Months of therapy

Commercial Growth Drivers

VIVITROL : LAI for the

Treatment of Opioid Dependence and Alcohol Dependence Extended-release opioid antagonist provides therapeutic levels of naltrexone for a one-month period Indicated for the treatment of alcohol dependence (AD) in patients able to abstain from alcohol

in an outpatient setting prior to initiation of treatment with VIVITROL Indicated for the prevention of relapse to opioid dependence (OD), following opioid detoxification Full prescribing information for VIVITROL may be found at

www.vivitrol.com/content/pdfs/prescribing-information.pdf. Treatment with VIVITROL should be part of a comprehensive management program that includes psychosocial support.

VIVITROL : Sales Fueled

Increasingly by Alcohol Dependence Indication COVID-19 Impact VIVITROL Net Sales ($M) Growth in Utilization for Alcohol Dependence TTM (trailing 12 month) data include Q4'20 through Q3'21 VIVITROL net sales results. +54% +38% +32% +4%

Commercial Growth Drivers

VUMERITY (Diroximel Fumarate)

for Multiple Sclerosis (MS) Novel oral fumarate for the treatment of relapsing forms of multiple sclerosis Discovered and developed by Alkermes Composition of matter patent extends into 2033

Novel oral fumarate for the

treatment of relapsing forms of multiple sclerosis (MS) Approved in U.S. Q4 2019 Biogen holds exclusive, worldwide license to commercialize 15% royalty to Alkermes on worldwide net sales ~$7B oral U.S. MS market* Multiple recent regulatory approvals

in Europe VUMERITY Offers Long-Term Revenue Growth Opportunity VUMERITY Royalty & Manufacturing Revenue ($M) *IQVIA NPA data as of Nov 2021 TTM (trailing 12 month)

Topline Growth and Diversification

Reflect Evolving Business *Licensed product (royalty & manufacturing revenue) Key product revenues drove 21% 5-year CAGR Commercial launch of LYBALVI in Q4 2021 provides additional revenue stream TTM (trailing 12 month) data include

Q4'20 through Q3'21 net sales results.

Innovation Focused on Unmet Patient

Need in Neuroscience and Oncology

R&D Objective: Novel Drug

Development With Differentiated and Disciplined Approach Leverage advanced medicinal chemistry and protein engineering capabilities to develop novel molecular entities with strong intellectual property protection Employ integrated approach to target

selection, development and lifecycle management with continuous evaluation of potential medical and economic value De-risk programs early by accelerating time to data and decision milestones and adhering to clear go/no-go criteria

Neuroscience and Oncology Pipeline

Neuroscience ALKS 1140 Neurology ALKS 2680 Narcolepsy HDAC Inhibitors Neurology/Neuropsychiatry Oncology Nemvaleukin alfa* Platinum-Resistant Ovarian Cancer Nemvaleukin alfa Mucosal Melanoma IL-12 IL-18 HDAC Inhibitors Preclinical Phase 1 Phase 2

Phase 3 Discovery *In combination with pembrolizumab

Inherently active, stable fusion

protein Nemvaleukin Alfa: Accumulating Data Support Critical Design Criteria Dose-dependent expansion of NK and CD8+ T cells, with minimal effects on Tregs Design Treg: Regulatory T cell; NK cell: Natural killer cell * Also granted FDA Orphan Drug