SEC Filing | Alkermes plc

Alkermes Presentation June 6, 2023

Alkermes develops, manufactures and commercializes innovative medicines Global pharma company headquartered in Ireland, founded in 1987 Financial Summary 5 Year Total Return 20% 0% -20% -40% ALKS: -38% -60% -80% Share Price ($) (06/02/23) 29.51 Basic shares outstanding (mm) 166.1 Market Cap ($M) 4,902 + Debt ($M) 293 - Cash ($M) 693 Enterprise Value ($M) 4,502 10 Source: Bloomberg (June 2, 2023)

Alkermes is made up of a patchwork of subscale business units Commercial products for addiction and mental illnesses Manufacturing Royalties from drugs with licensed Alkermes technology Research and Development Oncology (to be spun) 10

Alkermes’ assets are valuable, but the current business model traps and destroys shareholder value Alkermes if optimally run for shareholders is worth meaningfully more than the current valuation ALKS current valuation ALKS run for shareholders Upgrade Alkermes 10 Note: not to scale

Sarissa Capital has best-in-class expertise in constructive shareholder engagement in the healthcare sector 10 A bottom-up approach focusing on high quality drugs at deep value entry points. Actively works to execute an operational turnaround often through board influence and shareholder support Investment Process Sarissa Capital, founded in 2013, is an institutional fund focused on constructive shareholder engagement in the healthcare sector Strategy

Sarissa has a history of creating value for shareholders in the healthcare space Acquired 2020, $9.7 Bn 10 Acquired 2018, $11.6 Bn Acquired 2017, $5.2 Bn Acquired 2014, $3.85 Bn Position initiated 2015 Sarissa joined board 2016 Chairman of the Board 2018 - 2020 Position initiated 2017 Sarissa joined board 2017 Position initiated 2013 Sarissa joined board 2014 Chairman of the Board 2016 - 2017 Position initiated 2013

Although Sarissa feels strongly about board representation, we have made significant efforts to settle 10 We are trying hard to avoid this proxy contest and have offered reasonable settlement compromises including delaying our appointment to the board and making it contingent upon stock price targets not being met

Instead of accepting Sarissa’s latest proposal, Alkermes offered to meet with us twice per year Sarissa Alkermes Particularly odd given most companies meet with major shareholders at least four times per year as matter of course 10

BLUE VOTE THE UNIVERSAL CARD TO UPGRADE ALKERMES UPGRADEALKERMES.COM Vote before General Meeting of Alkermes shareholders scheduled for June 29, 2023. We urge all shareholders to vote today. 10 ONLY VOTE 1 CARD. DISCARD THE WHITE PROXY CARD Vote “FOR” the election of Sarissa Nominees Vote “AGAINST” the compensation of the Company’s named executive officers Vote “FOR” all other proposals in our proxy statement

Summary 10 Alkermes has destroyed meaningful shareholder value Alkermes is a hodgepodge of businesses Pops is the wrong person to lead Adding Sarissa representatives to the board of directors will add needed perspectives and skills and unlock shareholder value

Alkermes’ price performance since its early years in public market is dreadful compared to biotech index Nasdaq Biotechnology Index (NBI) started 11/1/1993 Difference of +1,429% 0% -500% 500% 1000% 1500% 2000% 3000% 2500% ALKS NBI Source: Bloomberg (6/2/23) 11 ALKS: +530% NBI: +1,959%

400% 350% 300% 250% 200% 150% 100% 50% 0% -50% -100% ALKS IBB XBI NBI ALKS price performance last 10 years ALKS: -4.9% XBI: +136% NBI: +124% IBB: +118% Difference up to 141% Source: Bloomberg (6/2/23) 11

ALKS price performance last 5 years 100% 80% 60% 40% 20% 0% -20% -40% -60% -80% ALKS IBB XBI NBI ALKS: -35.3% NBI: +21.2% IBB: +18.2% XBI: -10.4% Difference up to 56% Source: Bloomberg (6/2/23) 11

$0 $10 $20 $30 $40 $50 $60 $/Share ALKS recent stock price movement… déjà vu all over again Here we go again… Source: Bloomberg (6/2/23) 11

Since 2015 Alkermes has almost doubled revenue to >$1 Bn…but ALKS stock price has more than halved Source: Bloomberg (6/2/23) / Price performance shown from 1/2/2015 to 12/30/2022 Wide divergence in revenue growth and stock price indicates a real problem Alkermes stock price performance has been poor vs Indexes Alkermes has grown revenues by +77% since 2015 $628 $746 $903 $1,094 $1,171 $1,039 $1,174 $1,112 $600 $400 $200 $0 $800 $1,000 $1,400 $1,200 2015 2016 2017 2018 2019 2020 2021 2022 Revenue ($M) -80% -30% 20% 70% 120% 170% ALKS XBI 15 IBB NBI ALKS: -54.4% XBI: +32.2% NBI: +31.5% IBB: +28.6%

$903 $1,094 $1,171 $1,039 $1,174 $1,112 -$148 -$99 -$175 -$112 -$29 -$142 -$400 -$200 $800 $600 $400 $200 $0 $1,000 $1,200 $1,400 2017 2018 2019 2020 2021 2022 $M Despite multiple years with revenues >$1Bn, the company continues to operate at a loss Alkermes Revenue vs Operating Loss Revenue Operating Loss Revenue > $1 Bn 16 Operating loss Source: Alkermes corporate filings

Generating >$1 Bn in revenue for 5 years and still operating at a loss indicates a fundamental problem with the business model Impressive, I know. You try to do it! 16 How do you generate >$ 1 Bn in revenue every year and still lose money???

Alkermes burned through >$5.5 Bn in revenue over the last 5 years, the equivalent of buying the Boston Red Sox and still having ~$1 Bn left over… Source: Alkermes corporate filings and NBCsports.com + ~$1 billion cash 16

Management touts successful revenue generation but costs are out of control 2022 Revenue Expenses 2021 19 2020 2019 2018 Revenue Expenses Revenue Expenses Revenue Expenses Revenue Expenses1 Expenses = COGS + R&D + SG&A + Other, including amort of acquired intangibles Source: Alkermes corporate filings Expenses Revenues

Alkermes’ board needs shareholder representation to prevent further destruction of shareholder value 19

Summary 19 Alkermes has destroyed meaningful shareholder value Alkermes is a hodgepodge of businesses Pops is the wrong person to lead Adding Sarissa representatives to the board of directors will add needed perspectives and skills and unlock shareholder value

Generating >$1 Bn in revenue for 5 years and still operating at a loss indicates a fundamental problem with the business model Let me show you how it’s done… 19 How do you generate >$ 1 Bn in revenue every year and still lose money???

At its core, Alkermes is a patchwork of subscale businesses with bloated expenses “The House That Pops Built” 19 Commercial Large revenue potential but commercial model is subscale and fails to reach the economies of scale of larger pharma companies Royalties Valuable royalty revenue for out-licensed technologies that should fall directly to the bottom line and reward shareholders (do not) Manufacturing Alkermes manufactures drugs for itself and commercial partners but we believe not at a profit, are undersized and have had mishaps and delays Research and Development Inefficient R&D spend and a large proportion of revenues. Ex., its foray into cancer does not build on its expertise in neuropsychiatry

[1] Alkermes receives royalties on its proprietary technologies 19 Description of Current Key Royalty Streams Drug Indication(s) 2022 Net Product Sales Expiration Invega Products (JNJ1) Schizophrenia & Schizoaffective Disorder ~$4.1 Bn Patent royalties 2030 US - Know-how royalties with Interim Awards* Risperdal Consta (JNJ) Schizophrenia & Bipolar I ~$500 M 2023 Vumerity (Biogen) Multiple Sclerosis ~$550 M 2033 1Johnson and Johnson / Source: Corporate filings *ALKS received interim awards on 12/21/22 and 4/19/23 in its arbitration proceedings. Investors await further details

Collecting these royalties is incredibly lucrative and straightforward, like collecting checks Royalty Revenue Breakout 394 344 365 436 220 1 200 100 300 400 500 Revenues ($M) 0 2018 Risperdal consta 2019 2020 2021 Invega Ampyra/Fampyra Other 2022 Vumerity Expenses associated with royalties should be de minimis !Royalties in 2022 negatively impacted by dispute with JNJ Source: Alkermes corporate filings 25

What makes Alkermes’ spending so remarkable  for roughly 1/3rd of its revenue (royalties), expenses are de minimis1 36% 29% 35% 37% 20% $0 $200 $1,200 $1,000 $800 $600 $400 2018 2019 2020 2021 $M Royalties as % of Total Revenue Royalties Total Revenue !Royalties in 2022 negatively impacted by dispute with JNJ Source: Alkermes corporate filings 25 20221

Category Vivitrol Aristada Lybalvi Indication Alcohol and Opioid Use Disorder Schizophrenia Adult schizophrenia and Bipolar I Disorder Description Opioid receptor antagonist Long-acting injectable aripiprazole Combination of Zyprexa (olanzapine) and samidorphan Method of Administration Intramuscular injectable Q4W Intramuscular injectable Q4W or Q6W Daily oral tablet Year Launched 2006: alcohol dependence 2010: opioid dependence 2015 Fall 2021 2022 Revenues ($M) $379M $302M $96M 2023 Revenue Guidance ($M) $380M - $410M $315M - $345M $180 - $205M [2] Alkermes has 3 drugs that it commercializes Source: Alkermes corporate filings 27

Revenues from its commercial franchise have grown and are promising Commercial Revenues by Drug $363 $450 $524 $552 $627 $778 $900 $800 $700 $600 $500 $400 $300 $200 $100 $0 Revenues ($M) 2017 2018 2019 2020 2021 2022 Vivitrol Aristada Lybalvi Revenue CAGR: +16.5% Source: Alkermes corporate filings 27

But commercial revenues have come at a tremendous cost (i.e., inefficient) 74% 61% 58% 50% $0 $100 $200 $300 $400 $500 $600 $700 $800 2019 2022 $M Selling & Marketing (S&M) expenses as % of commercial revenues S&M expenses 2020 2021 Commercial franchise revenues Sales and marketing expenses have been grossly inefficient at >50% of commercial revenues (S&M as a % of total revenue would be misleading as historically ~1/3rd of total revenues are royalties that should drop to the bottom line) Source: Alkermes corporate filings 27

Aristada, Lybalvi, and Vivitrol target massive markets, far larger than what a midcap biotech can service efficiently Sources: Corporate presentation (3/2023) and 10-K (2/16/23) Schizophrenia Bipolar I Disorder Opioid Dependence Alcohol Dependence US market (adults) ~2,600,000 ~3,900,000 – 5,200,000 ~2,600,000 ~27,800,000 Alkermes’ medicines are valuable and address large market opportunities, but Alkermes cannot efficiently capture value 30

135 225 241 297 360 421 4.6 0 50 100 150 200 250 300 350 400 450 ALKS SNY PFE NVS MRK NVO LLY Enterprise Value ($Bn) Enterprise values of companies with salesforces Large pharmaceutical companies benefit from economies of scale and marketing muscle, leaving smaller companies like Alkermes at a disadvantage Source: Bloomberg (5/30/23) >29 fold! Hence, large pharma has historically commercialized neuropsychiatric medicines 31

Alkermes’ self commercialization model lacks economies of scale, destroying tremendous shareholder value More efficient use of salesforce Sales rep (Alkermes) Commercializing only a few drugs with call points that do not sufficiently overlap lacks scale Sales reps (Company B) 31

I think the key here is building out in a competitive space, both in schizophrenia and in addiction, building out a fully capable sales organization. And as we've grown, I think, to continue to show that long term gap in growth that Rich talked about that we're looking for in the top line, making sure that we have the right infrastructure in place, again to match the competitive nature in the antipsychotic market, but also to make sure that we have those field reimbursement managers and key account managers in VIVITROL, as Jim Robinson mentioned before. So yes, we absolutely have been investing in SG&A. Pops and his team admit the obvious: it is expensive for Alkermes to commercialize its drugs Sources: Q4’18 earnings call (2/14/19), Stifel 2023 CNS Day (3/29/23) Shareholders shouldn’t have to foot the bill to finance Pops’ inefficient strategies and empire-building aspirations Richard Pops (CEO), March 2023: Although Pops acknowledges it is expensive to build a commercial infrastructure, he still aspires to build a large commercial platform I think what people are learning is, it is quite expensive and time- consuming to build a commercial presence in some of these serious mental illness, government pay type settings. We now have proven ourselves with three products and if LYBALVI continues to execute, I think, furthering, burnishing the image of that platform, then that platform can take additional products in time. James Frates (CFO), February 2019, in response to why 2019 guided SG&A was ~60% above 2016 levels: 31

[3] Alkermes manufactures drugs for itself and third parties Wilmington, Ohio, USA Athlone, Ireland Tremendous shareholder capital has been spent developing manufacturing capabilities but unclear if Alkermes can excel at manufacturing Notable products manufactured at each facility: Source: Alkermes corporate materials 34

Manufacturing is not a core competency for Alkermes as recent missteps have shown Lybalvi Complete Response Letter Due to Manufacturing Vumerity Manufacturing Issues Lybalvi received a complete response letter from FDA in 11/2020 due to manufacturing concerns When Lybalvi was finally approved in 6/2021, launch was delayed until 10/2021 due to commercial manufacturing not being ready 10-Q (3Q22): "The decrease in manufacturing revenue in the three months ended September 30, 2022, as compared to the three months ended September 30, 2021, was primarily due to the manufacture of fewer commercial batches. We continue to work to address a manufacturing issue related to VUMERITY, which, if it persists, will continue to negatively impact our manufacturing revenue and may negatively impact our royalty revenues." Source: Alkermes corporate filings and press releases 35

133 104 119 106 112 100 80 60 40 20 0 120 140 2018 2019 2020 2021 2022 Revenues ($M) Risperdal consta Ampyra/Fampyra Other Vumerity Manufacturing revenues have been small and not growing Source: Alkermes corporate filings Stagnant revenues 36

133 104 119 106 112 20 0 80 60 40 120 100 140 2018 2019 2020 2021 2022 Manufacturing Revenues ($M) Alkermes’ manufacturing business lacks scale and is likely not profitable *Manufacturing expense estimate based on Sarissa assumptions of the following: ~1,000 employees as specified by the 2019 Alkermes corporate presentation. **Employee cost of ~$111k/employee based on Data USA public database: https://datausa.io/profile/naics/pharmaceutical-medicine-manufacturing Revenues ~$100-130M Personnel cost: ~1,000 employees* x $111K** = ~$111M Depreciation and other expenses Costs > Revenue 37

Alkermes’ manufacturing business can be optimized in the hands of the right company A company with scale and expertise in manufacturing can make better use of shareholder capital and minimize regulatory disruptions and commercial delays Company with established scale and expertise in manufacturing Value can be unlocked 37

[4] R&D pipeline reflects a company with expertise in neuropsychiatry spending heavily far afield in cancer with uncertain promise Source: Company Website (June 2023) First rule of R&D: Do something you’re not good at and see what happens 37

And it costs a lot: R&D spend at ~35-45% of revenue has been excessive 39% 44% 38% 35% 35% $0 $200 $1,200 $1,000 $800 $600 $400 2018 2019 2020 2021 2022 $M R&D as % of Total Revenue GAAP R&D Total Revenue >$2 Bn spent on R&D in the last 5 years! Source: Alkermes corporate filings 40

Lead oncology asset nemvaleukin has been expensive (external + est. internal R&D) $7 $8 $12 $45 $81 $161 $162 $170 $20 $0 $60 $40 $180 $160 $140 $120 $100 $80 2021 2022 $M Nemvaleukin Alfa (ALKS 4230) R&D Spend 2015 2016 2017 2018 2019 2020 External R&D Spend Estimated Internal R&D Spend* While tremendous shareholder capital has been invested in oncology, the payout remains unclear Sources: Alkermes corporate filings *Internal R&D spend for nemvaleukin was estimated by multiplying total internal R&D spend by nemvaleukin’s fraction of total external R&D spend External R&D includes CROs, consulting fees, lab services, product materials, and manufacturing activities Internal R&D includes employee-related expenses occupancy, depreciation, and overhead Likely >$650M has already been spent on nemvaleukin through 1Q23 41

After years, Alkermes admits the mismatch of costly cancer R&D within its core neuroscience business Alkermes press release June 2023 Even Alkermes now (belatedly) admits that the oncology business distracts the company from its neuroscience business and achieving profitability 42 Source: Company press release

Even within neuroscience, Alkermes has destroyed shareholder capital on wishful R&D programs Alkermes threw away millions running five Phase 3 trials on a drug to treat depression that was ultimately rejected by the FDA 42

Of the programs highlighted in the 2021 R&D Day, only orexin has a clearly articulated future Source: Alkermes Investor Day 2021 We agree ALKS 2680 is promising (high risk/high reward), but since its R&D Day in 2021, Alkermes burned hundreds of millions of dollars to achieve this Getting spun out 42

Unclear if anything of value will emerge from the acquisition of Rodin Therapeutics in 2019 Sources: pharmaceutical-technology.com, Alkermes 3Q2022 earnings call (11/2/22) ~3 years later “On the HDAC, we stopped the development of 1140, which was the first one we put in the clinic because of the metabolic profile. We have backups. We've gone to the backups now. We're seeing some encouraging things in the backups, but it's too early to say whether we're going to have another candidate that emerges because the threshold for nomination is quite high. We understand that both the chemistry and the biology that we want to achieve. And if we hit it, then we'll put another one into the clinic, but too early to call that right now.” Richard Pops provides updates on acquired assets from Rodin acquisition (November 2022): Lead asset from Rodin acquisition called ‘1140 ultimately failed in its first clinical trial 45

And that, folks, is how you generate >$ 1 Bn in revenue every year and still lose money Let’s see how much I can spend this year! 45 Generating >$1 Bn in revenue for 5 years and still operating at a loss indicates a fundamental problem with the business model

Summary 45 Alkermes has destroyed meaningful shareholder value Alkermes is a hodgepodge of businesses Pops is the wrong person to lead Adding Sarissa representatives to the board of directors will add needed perspectives and skills and unlock shareholder value

$60 $80 $120 $100 $40 $20 $0 7/16/1991 1/5/1997 6/28/2002 12/19/2007 6/10/2013 12/1/2018 $/Share Despite poor performance since 1991, one thing has been a constant: CEO Pops at the helm of Alkermes Source: Bloomberg (6/2/23) Dissolution of the Soviet Union 45 “The definition of insanity is doing the same thing over and over and expecting different results” - misattributed to Albert Einstein

We cannot trust Pops to get us out of this mess when he spent decades creating the mess "Morning, boys. How's the water?" "What the h*ll is water?" Source: Transcription of 2005 Kenyon Commencement Address (May 2005) given by David Foster Wallace 49

A masterful salesman, CEO Pops teases investors with false promises but never quite delivers Source: Alkermes earnings calls (4Q20, 1Q21 and 4Q22) 1In 2023 Years of emphasizing “a focus on profitability” Alkermes still remains GAAP unprofitable >$1bn in revenues still result in negative net income “Demonstrate the value of R&D investments” Hundreds of millions of annual R&D spend Unfocused pipeline often in incongruous indications “Leveraging the commercial infrastructure” Spent hundreds of millions to sell Aristada by itself for nearly 6 years Add’l 50 sales reps added in 2021 and $75-80M add’l direct to consumer spend1 to sell Lybalvi 50

Pops appears to offer alternative narratives Source: Alkermes conference call (6/1/21) and JPM conference call series (11/19/21) Richard Pops on 1Q21 earnings call (June 2021) J.P. Morgan Conference (November 2021) June 2021 – Pops attributes delay in Lybalvi launch to manufacturing issues Lybalvi receives a complete response letter from FDA due to manufacturing concerns (November 2020) Lybalvi finally approved in 6/2021 November 2021 (six months later) – Pops attributes delay in launch to Covid 51

Pops known to overpromise and underdeliver – here on timing of oncology updates Alkermes 1Q2023 Earnings (April 2023) Alkermes 3Q2022 Earnings (November 2022) Question: “…I feel like this will be so important to the valuation of spin, when should we be expecting a DSMB look into ARTISTRY-6 and 7 in 2023? …I got to believe investors that will be getting equity will be very curious about what's there to learn from the monotherapy and the combo trials? Richard Pops: ”…By the time we spin, we'll have very precise understandings about readouts, interim looks, if any, and other data that will augment the value proposition for the spin.” November 2022 – Pops promises data prior to oncology spin Question: “…Richard, can you remind us, what's the key clinical readout? …And to what extent would those readouts determine whether or not you are absolutely moving forward with the spin?” Richard Pops: ”…So the punch line to your question on the clinical trial is that we're going to spin while both ARTISTRY-6 and ARTISTRY-7 are still underway and blinded….” April 2023 (only months later) – Pops states no clinical trial data prior to spin 51

Pops has overpromised and underdelivered on a partnership for its oncology asset nemvaleukin for years *Source: Alkermes Earnings Call Transcripts 4Q2019 Earnings Call “Well, I think a lot will depend Pam on the exact partnership. I mean, as Rich outlined, there's both commercial as well as scientific logic to partnering 4230. And I think if we --the broadest sense, the way I think about it, if we have a partner, we can probably attack a lot more potential indications and spend a lot of money together with a partner.” 1Q2018 Earnings Call “…there's a number of companies who would be interested in working with 4230 in combination with their particular IO agent…So, we're having those discussions and an early partnership could be something where not a strategic business partnership but simply accessing somebody's IO agent and running a study together. And we have those discussions underway now” 1Q2021 Earnings Call “Our priorities are clear…advance nemvaleukin development program and seek partnership opportunities Pops has teased investors with a potential partnership of nemvaleukin for over 3 years… 51

Pops has lost credibility in the eyes of shareholders Alkermes’ largest blue-chip investor voted against them in 2021 and subsequently sold their entire stake Many institutional shareholders have voiced displeasure with Pops to Sarissa Press for change 51

*Preliminary Proxy 2023 51

For poor performance, Pops pads his pockets with excessive compensation Source: Alkermes Proxy Statement While the company is operating net income negative, Pops personally is REALLY net income positive 56

In fact, over the past 15 years, he has personally made >$150M* Shareholder Capital Alkermes 57 CEO Pops’ Net Worth Source: Alkermes Proxy Statements * Calculated by adding Richard Pops’ compensation from 2007-2022, inflation adjusted Over the last 15 years, Alkermes has a cumulative net loss >$1 Bn and Pops has taken home $150 M

Most interested in keeping his job, we understand Pops recently undertook a questionable roadshow to lobby against Sarissa representation on the board 57 We find this conduct highly unusual and concerning, particularly given that it occurred during the company’s quiet period and prior to the filing of any proxy materials with the SEC We believe that Mr. Pops should be focused on running the company instead of lobbying against shareholder representation on the board We view these actions as another example of the board’s insufficient oversight of Mr. Pops

$0 $20 $40 $60 $80 $100 $120 7/16/1991 1/5/1997 6/28/2002 12/19/2007 6/10/2013 12/1/2018 $/Share We can only speculate that CEO Pops cares more about his compensation and image than Alkermes’ stock price Source: Bloomberg (6/2/23) 57

Summary 57 Alkermes has destroyed meaningful shareholder value Alkermes is a hodgepodge of businesses Pops is the wrong person to lead Adding Sarissa representatives to the board of directors will add needed perspectives and skills and unlock shareholder value

Alkermes’ poor corporate governance impedes value creation CEO and Chairman Richard Pops has entrenched himself and ignores the proper governance checks and balances between the board and management Lack of shareholders, the owners of Alkermes, on the board Insufficient, half-hearted governance by Alkermes 57

The board waited 30 years to appease shareholders’ desire for profitability with a plan that is grossly inadequate and disregards the fundamental issues at Alkermes Source: Alkermes Press Release (December 2020) Only after heavy shareholder pressure, including from Sarissa, did Pops commit to “adjusted” profitability metrics in 2020 that will take 3-4 years to implement 57

Furthermore, the profitability commitments are on non-GAAP and vague metrics, giving the board plenty of “adjusting” room to obfuscate poor performance 1Calculated as earnings before interest, taxation, depreciation, amortization and one-time items, includes Alkermes Press Release December 2020 Alkermes’ non-GAAP net income and EBITDA exclude stock-based compensation but shareholders pay for this expense ($94M in 2022)! Ironically, although manufacturing is unlikely profitable, the depreciation of the expensive manufacturing plants is now helping the company reach its adjusted profitability targets share-based compensation expenses 63

Adjusted EBITDA vs EBITDA vs net income  explained Source: Twitter 5/30/2023 64 Of course, Alkermes’ net income is negative

Under pressure from shareholders, in 2020 Alkermes announced destaggering of the board but in a delayed and shareholder unfriendly way Source: Alkermes Proxy 2022 “On June 11, 2021, Mr. Gaffin and Mr. DiPaolo [Sarissa] discussed the Company’s proxy proposals for the 2021 AGM. Mr. DiPaolo expressed dissatisfaction with the timing of the process advanced by the Company to declassify the Board.” Alkermes Press Release May 2023 65 Announced in 2020, destaggering not to be completed in 2024

Governance at Alkermes has largely been controlled by Pops in Sarissa’s interactions Sarissa would like to discuss shareholder representation on the Board of Directors You can talk to me about that You can talk to Pops about that 65 Alkermes’ board For almost 2 years, Sarissa did not interact with any independent member of the Board or the Nominating and Governance Committee with discussions flowing almost exclusively through CEO Pops, contrary to good governance practices

Sarissa has had multi-year discussions on board representation with most conversations flowing through Pops Source: Sarissa press release (May 2022) 2020 2021 2022 2023 Sarissa discusses with CEO Pops the benefits of shareholder presence on the Board Sarissa continued to express concerns to CEO Pops regarding operational execution, capital allocation, and corporate governance Only after calling out the bad governance behavior did certain independent directors begin to have direct dialogue with Sarissa representatives Conversations with Pops Conversations with independent directors 65

Alkermes board rejected all Sarissa nominees in 2022 without ever meeting or speaking with them From my view, they are 65 unacceptable!

Our efforts to add Sarissa shareholder representatives to the board have been met with resistance and stalling tactics Having one of the largest shareholders on the board will help Alkermes be run for shareholders 65

Despite Sarissa’s expertise in company spin-offs, Alkermes shuns Sarissa representation on the board *Source: Ironwood/Cyclerion Press Release; Biogen/Bioverativ Press Release Sarissa’s success at orchestrating company spin-offs has created tremendous shareholder value Sarissa led spin-off deals 65

How Alkermes spins oncology is important  separation must be done to create shareholder value Source: Sarissa Press Release May 2018 71

After success in its arbitration against JNJ, Alkermes board hid that Sarissa urged the company to enter arbitration sooner and not delay the receipt of funds ii Calculated as earnings before interest, taxation, depreciation, amortization and one-time items, includes share-based compensation expenses. Alkermes 2022 Proxy Statement Alkermes 2023 Proxy Statement On March 2, 2022, Mr. DiPaolo and Mr. Gaffin spoke twice. Mr. Gaffin reiterated the Company’s interest in engaging with Dr. Denner in respect of the Second Sarissa Nomination Notice and inquired why Dr. Denner chose not to respond to Mr. Pops’ attempts at outreach. Mr. DiPaolo responded that he was not privy to Dr. Denner’s rationale. On March 2, 2022, Mr. Gaffin and Ms. Coombs conducted a conference call with Mr. DiPaolo, Mr. Kostas and Mr. Huang of Sarissa. During the call, the parties discussed recent publicly disclosed interactions between the Company and Janssen in respect of the notices of partial termination. Mr. DiPaolo inquired about the nature of the Company’s interactions and why the Company had not yet initiated arbitration or litigation in the matter. Mr. Gaffin responded that this information would constitute material non-public information and that, as such, he would not be able to comment. Mr. DiPaolo continued to question Mr. Gaffin on his opinion as to the odds of success in an arbitration with Janssen. Mr. Gaffin again declined to comment. Sarissa believed that Alkermes should have acted swiftly and aggressively on frivolous claims by JNJ. Why try to delay arbitration and introduce extra costs, delayed revenue, and volatility to the stock? 72 VS

Throughout our multiyear engagement, we have been patient and desired a settlement Alkermes email (May 3, 2023) 72

With a desire to settle and avoid a proxy fight, Sarissa made a significant concession to link board representation to stock performance but was summarily rebuffed Despite a reasonable compromise and a significant concession on our part, Alkermes rejected our proposal to link Sarissa board representation with Alkermes stock price 72

Board appears to have insufficient oversight of Pops Pops and not independent directors led NomGov discussions with Sarissa for years Pops reportedly soliciting votes during quiet period prior to filing proxy materials Board providing Pops’ lucrative compensation despite performance Alkermes’ culture of overpromising and underdelivering Board has allowed Pops to empire build  years of excessive spending with no coherent business strategy Directors Directors 72

Increasingly evident, Sarissa representative directors are needed to finally run Alkermes for shareholders Sarissa is uncertain why the board is so resistant to having direct shareholder representatives on the board of Alkermes We are your 3rd largest shareholder, and the largest non-index fund holder. You can’t come in 72

Alkermes refuses to add a Sarissa representative to the board 72 Sarissa mutually agreed with Pops for Alkermes to add Dr. Cato T. Laurencin (a non-Sarissa representative) to the board in 2021 as a good first step to providing fresh perspectives to the Alkermes’ board Sarissa believes that Dr. Laurencin is a good addition to the board, but still believes shareholder representation is essential Source: Alkermes Press Release, Today.uconn.edu

Sarissa is nominating three qualified individuals who are dedicated to unlocking shareholder value at Alkermes Patrice Bonfiglio Alex Denner, Ph.D. Sarah Schlesinger, M.D. 72

Alex Denner, Ph.D. Work Experience Currently: Founding partner and Chief Investment Officer of Sarissa Capital Management LP Prior, include: Senior Managing Director at Icahn Capital Portfolio Manager at Viking Global Investors Healthcare portfolio manager at Morgan Stanley Investment Management Board Experience Currently: Biogen Inc. (Chair of Corporate Governance Committee) Ironwood Pharmaceuticals (Chair of Gov-Nom Committee) Attralus, Inc. Prior, include: The Medicines Company (Chairman) Bioverativ ARIAD Pharmaceuticals (Chairman) Amylin Pharmaceuticals ImClone Systems (Chairman, Chairman of Executive Committee) 72

Patrice Bonfiglio Work Experience Currently: President at Sarissa Capital Chief Operating Officer, Chief Financial Officer and Chief Compliance Officer of Sarissa Capital Prior, include: Head of Operations at Arbalet Capital Operations Manager at Arrowhawk Capital Senior Accountant at Ridgefield Capital Associate and Fund Accountant at Pequot Capital Board Experience Currently: Amarin Corp 72

Sarah Schlesinger, M.D. Work Experience Currently: Associate Professor at Rockefeller University Senior Attending Physician at Rockefeller University Hospital • Prior, include: Scientist at Vaccine Research and Design International AIDS Vaccine Initiative Research Physician at Walter Reed Army Institute of Research Board Experience Currently: Innoviva, Inc. (Chair of Nominating/Corporate Governance Committee) Armata Pharmaceuticals Prior, include: The Medicines Company ARIAD Pharmaceuticals (Chair of Science and Medicine Committee) 72

We expect the company to argue that Denner, as a director of Biogen, has a conflict of interest since Biogen is partnered with Alkermes for Vumerity… The Excuses Hat of Alkermes 72

…but Alkermes cleared conflicts for a Biogen director (not named Alex Denner) to join the Alkermes board Source: Email agreement between Alkermes management and Sarissa Alkermes email Alkermes email Biogen Director Biogen Director Candidate’s employer Candidate’s employer 72

Blocking Denner from joining the Alkermes board is really a desire to keep Sarissa off the board, not because of purported conflicts of interests Sarissa and Alkermes agreed to a list of acceptable board candidates, which included a Biogen board member, to join in 2022 Biogen Board Member (not named Alex Denner) Seems like Biogen board membership isn’t “conflict of interest,” but rather, Pops’ desire to keep Sarissa off the board! 72 Pops subsequently rejected Alex Denner as a board candidate citing his service on Biogen board

Without clear explanations why Alkermes will not accept our candidates, we can only speculate they fear the following: Sarissa will introduce oversight by shareholders Sarissa will show that the company’s business model is flawed The era of complacency with capital allocation will come to a close Shareholders will realize old Alkermes wasted billions of dollars on poor R&D choices The issues with manufacturing and its lack of profitability at Alkermes come to light Sarissa will take credit for the oncology spin Alkermes board appears insistent on insulating itself from shareholder oversight and accountability 72

$60 $80 $120 $100 $40 $20 $0 7/16/1991 1/5/1997 6/28/2002 12/19/2007 6/10/2013 12/1/2018 $/Share DO NOT RE-ELECT RICHARD POPS  Despite poor performance since 1991, one thing has been a constant: CEO Pops at the helm of Alkermes *Blank Dissolution of the Soviet Union 72 “The definition of insanity is doing the same thing over and over and expecting different results” - misattributed to Albert Einstein

DO NOT RE-ELECT RICHARD GAYNOR  a cancer specialist is no longer needed on the board as Alkermes refocuses on neuroscience Source: Alkermes Press Release The value of 18 years of experience in oncology-focused drug development (to use Alkermes’ words) is now irrelevant except perhaps with the oncology spin 87

DO NOT RE-ELECT SHANE COOKE Alkermes needs a fresh perspective and not another long-term member of Alkermes’ management on its board Cooke filled his retirement from Alkermes with…more Alkermes. Shareholders don’t need more of the same at Alkermes as the company’s past performance has shown 88 Source: Alkermes Website

Summary 88 Generating >$1 Bn in revenue for 5 years and still operating at a loss indicates a fundamental problem with the business model Alkermes continues to destroy shareholder value Substantial shareholder value can be unlocked if Alkermes were run for the benefit of shareholders Sarissa is nominating three qualified candidates to join the Alkermes board and upgrade the company for all shareholders The current board of directors refuses involvement from major shareholder with a long history of creating value Sarissa continues to make efforts to settle

BLUE VOTE THE UNIVERSAL CARD TO UPGRADE ALKERMES UPGRADEALKERMES.COM Vote before General Meeting of Alkermes shareholders scheduled for June 29, 2023. We urge all shareholders to vote today. 88 ONLY VOTE 1 CARD. DISCARD THE WHITE PROXY CARD Vote “FOR” the election of Sarissa Nominees Vote “AGAINST” the compensation of the Company’s named executive officers Vote “FOR” all other proposals in our proxy statement

Shareholders can vote in one of three easy ways: Voting by Internet – Visit www.cesvote.com. You will be prompted to provide the unique control number featured on your BLUE universal proxy card. Vote by Phone – Dial the toll-free number 1-888-693-8683. You will be prompted to provide the unique control number featured on your BLUE universal proxy card. Voting by Mail – Sign, date and return your BLUE universal proxy card in the postage-paid envelope sent to you. 88 The General Meeting of Alkermes shareholders is scheduled for June 29, 2023. We urge all shareholders to vote today “FOR” the election of the Sarissa Nominees, “AGAINST” the compensation of the Company’s named executive officers, and “FOR” all other proposals in our proxy statement. Shareholders are strongly encouraged to submit their votes today or risk having their votes not counted

BLUE 88 If you have any questions regarding your proxy card or need assistance in executing your proxy card, please contact: D.F. King & Co., Inc. 48 Wall Street New York, New York 10005 Shareholders call toll-free: (866) 207-3648 Banks and Brokers call: (212) 493-6952 By Email: ALKS@dfking.com VOTE THE BLUE PROXY CARD TODAY FOR YOUR VOTES TO COUNT AT THE ALKERMES’ ANNUAL GENERAL MEETING OF SHAREHOLDERS ON JUNE 29, 2023

Disclosures 88 GENERAL CONSIDERATIONS This presentation is for general information purposes only, is not complete and does not constitute an agreement, offer, a solicitation of an offer, or any advice or recommendation to enter into or conclude any transaction or confirmation thereof (whether on the terms shown herein or otherwise). The views expressed in this presentation represent the opinions of Sarissa Capital Management LP and certain of its affiliates (collectively, “Sarissa”), which beneficially own shares of Alkermes plc (the “Company”) and are based on publicly available information with respect to the Company. Sarissa recognizes that there may be confidential information in the possession of the Company that could lead it or others to disagree with Sarissa’s conclusions. Sarissa has neither sought nor obtained the consent from any other third party to use any statements or information contained herein that have been obtained or derived from statements made or published by such third parties, nor has it paid for any such statements. Any such statements or information should not be viewed as indicating the support of such third parties for the views expressed herein. Sarissa does not endorse third-party estimates or research that are used in this presentation solely for illustrative purposes. No warranty is made that data or information, whether derived or obtained from filings made with the Securities and Exchange Commission (“SEC”) or any other regulatory agency or from any third party, is accurate. Past performance is not an indication of future results. Certain financial information and data used herein have been derived or obtained from filings made with the SEC or other regulatory authorities and from other third party reports. Neither Sarissa nor any of its affiliates shall be responsible or have any liability for any misinformation contained in any third party SEC or other regulatory filing or third party report. The figures presented herein may not have been calculated using generally accepted account principles (“GAAP”) or international financial reporting standards (“IFRS”) or audited by independent accountants. Such figures may vary from GAAP and IFRS accounting in material respects, and there can be no assurance that any unrealized values reflected herein will be realized. Further, there is no assurance or guarantee with respect to the prices at which any securities of the Company will trade, and such securities may not trade at prices that may be implied herein. The estimates, projections and potential impact of the opportunities identified by Sarissa herein are based on assumptions that Sarissa believes to be reasonable as of the date of this presentation, but there can be no assurance or guarantee that actual results or performance of the Company will not differ, and such differences may be material, or that any of the assumptions provided in this presentation are accurate. This presentation does not recommend the purchase or sale of any security. Sarissa disclaims any obligation to update the data, information or opinions contained in this presentation.

Disclosures 88 NOT AN OFFER TO SELL OR BUY Under no circumstances is this presentation intended to be, nor should it be construed as, an offer to sell or a solicitation of an offer to buy any security. This presentation does not recommend the purchase or sale of any security and should not be construed as legal, tax, investment or financial advice or advice on the merits of any investment decision. Sarissa currently beneficially owns shares of the Company. Sarissa is in the business of buying and selling securities and intends to continue trading in the securities of the Company. It is possible that there will be developments in the future that cause Sarissa from time to time to sell all or a portion of its holdings of the Company in open market transactions or otherwise (including via short sales), buy additional shares (in open market or privately negotiated transactions or otherwise), or trade in options, puts, calls, swaps or other derivative instruments relating to such shares, regardless of the views expressed in this presentation. Sarissa reserves the right to take any actions with respect to investments in the Company as it may deem appropriate, and to change its intentions with respect to investments in the Company at any time as it deems appropriate, and Sarissa disclaims any obligation to notify the market or any other party of any such changes, except as required by law. CAUTIONARY STATEMENT REGARDING FORWARD-LOOKING STATEMENTS This presentation contains forward-looking statements. All statements contained herein that are not clearly historical in nature or that necessarily depend on future events are forward-looking, and the words “anticipate,” “believe,” “expect,” “potential,” “could,” “opportunity,” “estimate,” “plan,” and similar expressions are generally intended to identify forward-looking statements. The projected results and statements contained herein that are not historical facts are based on current expectations, speak only as of the date of this presentation and involve risks, uncertainties and other factors that may cause actual results, performances or achievements to be materially different from any future results, performances or achievements expressed or implied by such projected results and statements. Assumptions relating to the foregoing involve judgments with respect to, among other things, future economic, competitive and market conditions and future business decisions, all of which are difficult or impossible to predict accurately and many of which are beyond the control of Sarissa. Although Sarissa believes that the assumptions underlying the projected results or forward-looking statements are reasonable as of the date of this presentation, any of the assumptions could be inaccurate and therefore, there can be no assurance that the projected results or forward-looking statements included herein will prove to be accurate. In light of the significant uncertainties inherent in the projected results and forward-looking statements included herein, the inclusion of such information should not be regarded as a representation as to future results or that the objectives and strategic initiatives expressed or implied by such projected results and forward-looking statements will be achieved. Except to the extent required by applicable law, Sarissa will not undertake and specifically declines any obligation to disclose the results of any revisions that may be made to any projected results or forward-looking statements herein to reflect events or circumstances after the date of such projected results or statements or to reflect the occurrence of anticipated or unanticipated events.

Disclosures 88 CONCERNING INTELLECTUAL PROPERTY All registered or unregistered service marks, trademarks and trade names referred to in this presentation are the property of their respective owners, and Sarissa’s use herein does not imply an affiliation with or endorsement by the owners of these service marks, trademarks and trade names. ADDITIONAL INFORMATION Sarissa Capital Management LP (“Sarissa Capital”), together with other participants, filed a definitive proxy statement and an accompanying BLUE universal proxy card with the SEC on June 2, 2023, in connection with the solicitation of shareholders of the Company for the 2023 annual general meeting of shareholders (the “Annual Meeting”). Shareholders are advised to read the definitive proxy statement and other documents related to the Annual Meeting as they contain important information. The definitive proxy statement and other relevant documents are available at no charge on the SEC’s website at www.sec.gov. The definitive proxy statement and other relevant documents filed by Sarissa Capital are also available at no charge at www.upgradealkermes.com or by directing a request to Sarissa Capital’s proxy solicitor, D.F. King & Co., Inc., 48 Wall Street, New York, New York 10005 (Shareholders can call toll-free: (866) 207-3648).