Satsuma Pharmaceuticals (STSA) 8-K Satsuma Pharmaceuticals Provides STS101 Development Program and Corporate Update

Exhibit 99.2

pharmaceuticals STS101 program and corporate overview NASDAQ: STSA | December 20, 2022

Satsuma Pharmaceuticals corporate summary and STS101 program overview 2

Satsuma Pharmaceuticals (Nasdaq: STSA) Focus • Developing STS101 (DHE nasal powder) for the acute treatment of migraine o Differentiated, NDA-stage asset with low regulatory risk and significant commercial potential Financial • Cash and equivalents as of October 31, 2022: $59.4M • Basic shares outstanding as of 9/30/2022: 33.1M (not including 5.3M options outstanding) • No debt • Net operating loss carryforwards Other • 25 employees, with particular expertise in developing drugs and respiratory-route drug-device combination products • Offices in South San Francisco and Durham, NC with remaining lease terms expiring or terminable in 2023 o No laboratories or manufacturing facilities • Established in June 2016; Initial Public Offering in September 2019 • High-quality, science-focus shareholder base, with insiders owning >25% of outstanding shares 3

STS101: dihydroergotamine (DHE) nasal powder Differentiated, NDA-stage asset with fast, low-cost / low-risk path to FDA approval and significant commercial potential • Indication: acute treatment of migraine with or without aura in adults • Large clinical trial program: >1,600 subjects who treated >9,000 migraine attacks with STS101 for up to 18 months o Includes SUMMIT Phase 3, double-blind, placebo-controlled efficacy trial (1,424 subjects in mITTpopulation) • Based on feedback from legal-regulatory experts, we are confident STS101 is approvable via the 505(b)(2) regulatory pathway and believe there is a strong case for including SUMMIT Ph3 trial efficacy results in the STS101 label • Upon reviewing SUMMIT results, headache specialists and KOLs voice strong interest in and intent to prescribe STS101—despite STS101 not demonstrating statistical significance in SUMMIT trial against co-primary endpoints at 2h • Timeline* Q1 2023 Q2 2023 Q3 2023 Q4 2023 Q1 2024 Q2 2024 File NDA NDA approval Commercial introduction • Low cash investment required to fund STS101 program through NDA approval • Protected by broad and long-lived intellectual property portfolio o 10 issued US patents; last issued patent has estimated expiration date of Dec 2039 *with commercialization partner 4

STS101 is the first and only DHE product with potential for broad utilization TRUSTED AND POWERFUL Active, dihydroergotamine (DHE) has long been considered a gold-standard treatment for migraine PROVEN EFFICACY IN SUMMIT PH3 TRIAL Robust and long-lasting efficacy through 48h with single dose Numerical separation vs placebo as early as 1h after treatment Efficacy results superior to those from placebo-controlled trials of approved DHE products SIMPLICITY Easy-to-use and easy-to-carry Self-administration of a full dose in seconds No assembly or priming required FAVORABLE SAFETY AND TOLERABILITY Low rates of adverse events, including nausea (1.9%) Most common AEs in SUMMIT trial were nasal discomfort (8.3%) and dysgeusia (3.7%) AEs were predominantly mild and transient 5

Available DHE products are not easy-to-use, well-tolerated or consistently effective DHE forInjection DHE liquid nasal sprays (IV, IM, SC) sprays Marketed since 1946 MIGRANAL: approved in 1997 Trudhesa: approved 2021 Highly variablePK results in unreliable clinical Considered gold standard treatmentfor performance and suboptimal therapeutic severe / refractory migraine response for many patients • Effectiveness not supported by any Exact same formulation and vial as MIGRANAL; • Poor and inconsistent efficacy in clinical trials controlled clinical trials for efficacy only different spray device (large, single-use) • Alleviates pain & symptoms but does not • Never evaluated as monotherapy in abort attacks • PK only incrementally better than MIGRANAL placebo-controlled trial • Low, slow, and highly variable absorption due • Not evaluated for efficacy in any RCT; effectiveness • Injections are painful and burdensome supported by MIGRANAL efficacy trial results to inherent nature of liquid spray formulation • Patients prefer non-injectables • High rates (>50%) of bothersome local irritative • Complex, multi-stepadministration procedure • Nausea, vomiting and other side effects nasal symptoms, e.g., congestion    Ì¶ Assembly & priming required occur more frequently with injection ̶ Removing metal band on vial poses laceration risk • Complex, multi-stepadministration procedure • Frequently requires HCP administration ̶ 4 sprays administered over 15 minutes similar to MIGRANAL STS101 addresses the unmet need for an easy-to-use, non-injected DHE product that delivers prompt, robust and sustained efficacy 6

STS101 PK profile is optimized to maximize efficacy while minimizing side effects Establishes PK bridge to listed products (MIGRANAL and DHE for injection) required for 505(b)(2) pathway approval Rapidly achieves and sustains target drug plasma concentrations that maximize efficacy while minimizing AEs, in particular iatrogenic nausea STS101 PK profile predicted to translate to robust and sustained efficacy More drug on board faster: 2-3 times greater drug exposure with reduced PK variability versus approved DHE liquid nasal sprays—with lower rates of most adverse events Lower incidence of nausea than DHE for injection 7

Intuitive simple administration –a full dose within seconds 1 2 3 FOLD OFF TAB INSERT IN ONE NOSTRIL SQUEEZE TO DELIVER 8

SUMMIT Phase 3 efficacy trial summary (1,424 subjects in mITTpopulation) • Randomized, double-blind, controlled trial comparing STS101 5.2 mg (single dose) and placebo • STS101 (single dose) demonstrated robust and sustained anti-migraine efficacy, but did not achieve statistical significance on pre-specified co-primary endpoints of % Free from Pain and % Free from Most-Bothersome Symptom* (MBS) assessed at two hours post-treatment • Statistically superior (p<0.001) to placebo on both co-primary endpoints at all time points from 3h through 48h Co-primary endpoints assessed at 2h p=0.0552 p=0.0002 Co-primary endpoints assessed at 2h p=0.1661 p=0.0009 Subjects who did not report data at a timepoint or who used any rescue medication prior to timepoint were imputed to be treatment failures 9 *from among photophobia, phonophobia or nausea

STS101 is a differentiated and best-in-class DHE product We believe STS101 availability will drive broader utilization of DHE Key attributes STS101 MIGRANAL & DHE for injection Robust efficacy demonstrated in Yes No No placebo-controlled trials? Favorable safety and tolerability Yes No No profile, with low rates of nausea? Superior form factors? Yes No No Quick and easy to self- Yes No No administer? Compact and easy to carry? Yes No ?? New and unique dosage form? Yes No No Laceration or needlestick risk? No Yes Yes 10

Market dynamics for Rx migraine treatments are favorable Today Future Total acute treatment market is Favorable long-term dynamics: comprised of both Migraine-specific Market for migraine-specific treatments is large, growing and Nonspecific treatments and has significant long-term growth potential Capable of supporting multiple competitors with differentiated branded treatments KEY DRIVERS Migraine-specific treatments Migraine-specific Large pharma marketing Segment expansion as result of: Promotion, including DTC • Increasing # of pts seeking treatment treatments Migraine awareness • Increasing diagnosis rates triptans, gepants, DHE, lasmiditan initiatives • Increasing treatment rates • Share capture from nonspecific segment Education Increased share of overall market Nonspecific treatments Education Nonspecific treatments General trends away from Reduced use of opioids and NSAIDS, acetaminophen, opioids, barbiturates opioid use barbiturates Decreasing share of overall market 11

Acute treatment of migraine market is large and has considerable room to grow STS101 is well-positioned to capture significant market share 1 Large number of patients are 2 Physicians and patients are highly interested in STS101 candidates for treatment with • Physicians see STS101 has having broad therapeutic utility STS101 • High prescribers of migraine therapeutics anticipate prescribing STS101 for ~30% of patients* Migraine: ~40M U.S. • Large patient population prevalence Only ~40% received a medical diagnosis for • Historically under-diagnosed and under-treated migraine in preceding year • Large proportion of patients prescribed non-specific treatments, including opioids, barbiturates, combination analgesics, etc. Only ~26% currently using • Disease awareness and DTC promotion by large pharma players will continue to increase #s of pts Dx’d and treated with acute migraine-specific Rx migraine-specific Rx medications treatment • Pfizer and Abbvieproject peak gepantsales of $6B and $2B, respectively High discontinuation rates • ~20-40% of patients have inadequate relief with current treatments with current treatments • Many patients cycle through multiple treatments reflect dissatisfaction and • Up to 2/3 of patients prescribed a triptan do not refill initial Rx significant unmet needs • ~50% of patients prescribed a gepantdo not refill initial Rx within 60d Candidates for treatment • Large pool of patients with unmet needs that STS101 can address with STS101 *based on survey of 100 physicians shown STS101 product profile incorporating SUMMIT trial results 12

The acute treatment of migraine market is large and rapidly growing, with a relatively small group of high prescribers driving growth U.S. Prescriptions for Migraine-Specific Acute Treaments1 Commercial success of new migraine products underscores large market opportunity, significant unmet 2021 US net sales of Biohaven & Abbvie gepants2 exceeded $1B needs and favorable dynamics • New product introductions have expanded market • Double-digit revenue growth in both acute and 72% gepant2 TRx growth YTD preventive categories • >$2B 2021 net sales of new products in U.S. • Concentrated high-prescriber audience: ~12k physicians wrote ~80% of 2021 gepantprescriptions Market for non-oral treatments is significant, with opportunity for introduction of new and better products, e.g., STS101, to drive segment growth Preventive MAbs available >4M dose units / year (liquid nasal sprays, (Lilly, Amgen, Teva, Lundbeck) • 2021 US net sales: $992M injectables and rectal suppositories) ~20% YTD ‘22 sales growth thru Q3 • DHE segment is >520k dose units/year (mostly liquid nasal sprays) and growing 1. TRx’s include those attributable to preventive use of rimegepant, as prevention indication approved by FDA in late May 2021 13 Source: IQVIA data and company reports 2. Ubrogepant and rimegepant

STS101 program overview STS101 All clinical trials necessary for Late-stage asset with significant Acute treatment of migraine (DHE nasal powder) NDA filing are complete commercial potential Large and growing multi-billion We believe STS101 is approvable, First and only DHE product suitable dollar market, with favorable with strong case for including Key objectives for broad use dynamics SUMMIT efficacy data in STS101 label • 40M U.S. prevalence Secure STS101 commercialization • DHE is differentiated and well-established treatment for migraine • Underdiagnosed and undertreated partner, and: STS101 demonstrated robust and • Project ~20M Rx’s for migraine— File NDA: Q1 2023 • Not orally bioavailable sustained efficacy with single dose, specific treatments written in 2022 but did not achieve statistical—NDA approval: early Q1 2024 • Approved injectable and liquid • ~20-40% of patients do not obtain significance on co-primary nasal spray dosage forms are—Commercialize in early Q2 2024 adequate relief with current endpoints suboptimal treatments • Only STS101 provides what • ~50% of gepant Rx’s not refilled physicians have long desired in a within 60 days STS101 demonstrates favorable DHE product safety and tolerability in long-term, • Market for non-oral treatments open-label safety trial 4M unit doses/year STS101 Significant commercial potential Robust efficacy profile demonstrated in large RCT is consistent with physicians’ views of the efficacy of DHE administered by injection Can address unmet needs of many people with migraine Favorable safety and tolerability demonstrated in 1,600 subjects who have self-administered 11,000 doses of STS101 Can broaden utilization of DHE and enable more patients to Quick and easy to self-administer enjoy DHE benefits 14

Dihydroergotamine (DHE) for injection is viewed by HCPs as highly effective DHE for injection Clinical attribute Triptans DHE • First approved in 1946 Long treatment window with minimal attenuation of effect when administered late in • Long recommended as a first-line option for course of attack1 × the acute treatment of migraine Opportunity for early treatment possible in only ~50% of attacks2 • Unique and multi-faceted MoA Low risk of 24+ hr headache recurrence3 Recurrence in up to 45% of triptan-treated attacks3 × • Significant advantages over triptans and new acute treatments (gepants & lasmiditan) Effective in migraine with allodynia4 Present in majority of attacks (53-79%)5 × • Broad clinical utility, including for difficult-to-treat migraines & triptan insufficient Effective in triptan non-responders6 responders ~40% of patients don’t respond* to oral triptans;7 × ~50% of triptan non-responders shown to respond to DHE6 • DHE could address many shortcomings of triptans and gepants and see broad use if Low risk of medication overuse headache8 × available in a non-injectable dosage form that was easy-to-use, well-tolerated and Sources: 1. Tepper, Mayo Clin Proc 2011 5. Lipton, Headache 2017 consistently effective 2. Valade, Cephalalgia 2009 6. Fisher, Curr Med Res Opin 2007 3. Winner, Arch Neurology1996 7. Ferrari, Cephalalgia 2002 4. Tepper, Headache 2012 8. Saper, Headache 2006 *40% based on pain relief at 2 hours from administration; up to 80% do not achieve sustained freedom from pain 15

STS101 (DHE nasal powder) is unique, highly innovative and designed to meet the needs of people with migraine Proprietary, advanced dry-powder formulation technology and single-use nasal delivery device Simple MucoAdhesiveRelease Technology (SMART) combines mucoadhesive drug carrier and engineered drug particle technologies to provide rapid and sustained drug absorption More drug on board faster: ~2-3 fold greater drug exposure with reduced PK variability versus approved DHE liquid nasal sprays—with lower rates of most adverse events 16

How STS101 DHE nasal powder works 1 Creates a steep drug concentration DHE gradient across nasal membrane that drives rapid absorption DRUG CARRIER Mucoadhesive particles adhere to 2 nasal mucosa, providing sustained delivery of DHE over time Not feasible with liquid DHE 3 formulations due to poor solubility of DHE and inherent nature of liquids NASAL MUCOSA Sources: Thorne et al., Nature Scientific Reports, Aug 2016; Bitter et al., Curr Probl Dermatol., 2011; Torikai et al., J Pharm Sciences 2020 17

How STS101 DHE nasal powder works Human nasal anatomy STS101 formulation engineered to 1 maximize deposition on surface of respiratory mucosa (97% of nasal mucosal surface) STS101 target tissue 2 Less drug run off/loss out of nose and down throat vs liquid nasal sprays Respiratory mucosa • 5x more vascularized and ~2x more permeable than upper / olfactory mucosa Sources: Thorne et al., Nature Scientific Reports, Aug 2016; Bitter et al., Curr Probl Dermatol., 2011; Torikai et al., J Pharm Sciences 2020 18

STS101 is the first and only DHE product suitable for broad use • STS101 has key differentiating features long desired by physicians in a DHE product: ✓Proven robust and long-lasting efficacy with single dose ✓Quick and easy self-administration ✓Favorable safety and tolerability, with low rates of local nasal irritative symptoms and iatrogenic nausea/vomiting • SUMMIT efficacy results are consistent with physicians’ views of the efficacy and therapeutic utility of DHE for injection (but not DHE liquid nasal sprays) ✓Robust and long-lasting efficacy, with ability to “break” and abort attacks ✓Beneficial for difficult-to-treat and long-duration attacks ✓Beneficial for refractory attacks and as a rescue medication • STS101 SUMMIT trial efficacy results are superior to efficacy results demonstrated with approved DHE products in placebo-controlled trials • STS101 ease-of-use and favorable safety / tolerability are differentiating features that we believe will increase utilization of STS101 beyond current DHE products 19

Market for acute treatment of migraine therapies and STS101 commercial opportunity 20

Growing market with concentrated high-prescriber audience ~15k physicians prescribe ~40% of all migraine-specific acute treatments Est. 2024 Rx’s for Large pharma DTC promotion and disease awareness initiatives will continue to migraine-specific focus on building and expanding market treatments Pfizer and Abbvie project peak sales of their gepants at $6B and $2B, respectively ~21M Rx’s Objectives: written by 1. Increase % of people with migraine diagnosed ~447k HCPs 2. Increase % treated with migraine-specific medications TIER 1 Core target audience • Segment represents $7.5B branded opportunity at branded WAC price of ~$1,000 per Rx ~7.4M Rx’s • Each 1% share of Rx’s written by Tier 1 physicians has a value of ~$80M at WAC prices written by • TIER 1 HCPs anticipate prescribing STS101 for ~30% of their migraine patients (based on 100-~15k HCPs physician survey in which respondents were shown STS101 profile incorporating SUMMIT trial results) TIER 2 ~5.5 M Rx’s Secondary target audience written by • Tier 2 physicians anticipate prescribing STS101 for ~30% of their migraine patients* ~50k HCPs 21 Source: IQVIA data *based on primary market research completed prior to read-out of SUMMIT trial results using product profile showing statistically significant effects on co-primary endpoints at 2h post-treatment

STS101 is uniquely positioned for broad use STS101 overcomes deficiencies of STS101 in the migraine treatment paradigm injectable and liquid nasal spray Significant CV disease DHE products, enabling broader or risk factors? utilization of DHE ? Triptan No Yes Gepant or Inadequate response ? or poor tolerability? lasmiditan Yes Gepant and/or STS101 depending on patient and her/his typical attacks ? Inadequate responseto gepant? Yes STS101 (monotherapy or as add-on to gepant) STS101 prior to prescribing opioids, barbiturates, etc. 22

Pricing of newer branded and DHE liquid nasal spray products indicated for the acute treatment of migraine Product WAC per dose Note that price / dose does not necessarily reflect cost of a treating an attack, as multiple doses of a Newer oral branded products product are frequently required and utilized in Nurtec $114.91 treating a single attack Ubrelvy $93.13 For example, across all UBRELVY Phase 3 trials, Reyvow $88.20 subjects treating their attacks with Ubrelvy took an DHE liquid nasal spray products optional second-dose or another rescue medication Trudhesa $223.13 in treating ~50-60% of attacks Migranal $477.87 Migranal generics $300 -$428 Source: IBM Micromedex, August 4, 2022 Sources: Ubrelvy Summary Basis of Approval; Ailani et al., Headache 2020; MIGRANAL SUMMARY Basis of Approval 23

Previous Satsuma primary market research conducted with HCPs, patients and payers* points to large STS101 commercial opportunity Satsuma primary market research summary* HCPs (qualitative and quantitative, including survey results from ~700 physicians) 70% of surveyed physicians expressed high interest in STS101 Viewed STS101 as having broad utility for a wide range of migraine patients and attack types High (top 3.5 decile) and medium (decile 3.5 – 7) prescribers of migraine-specific therapies anticipate prescribing STS101 to ~30% of their patients—Prescribing intent did not depend on size of STS101 treatment effect versus placebo In post-SUMMIT trial survey utilizing STS101 profile with SUMMIT trial results, high prescribers (n=100) anticipated prescribing STS101 to ~30% of their patients Patients (qualitative research) 80% of patients interviewed were either very or extremely interested in STS101 Payers (qualitative research) Payer research has not identified any unexpected barriers to access Key drivers of STS101 interest Familiarity with and positive view of DHE (physicians) STS101 simplicity and ease-of-use (physicians and patients) *based on primary market research completed prior to read-out of SUMMIT trial results using product profile showing statistically significant effects on co-primary endpoints at 2h post-treatment 24

STS101 commercial opportunity and positioning STS101 is an appropriate and evidence-based treatment for a wide variety of patients and attack types: Insufficient responders to triptans and/or gepants • 20-40% of patients do not achieve adequate relief with current treatments • Prescription discontinuation rates for both triptans and gepants are high (up to 67% and ~50%, respectively) • Triptans are poorly effective in attacks with allodynia (>50% all attacks), and there is no data to support gepant effectivenessin attacks with allodynia • Migraine recurrence is common (up to ~45%) following initial treatment with a triptan • Opioids and barbiturates are still extensively prescribed for migraine (~20% to >50% of patients), despite risk of medicationoveruse headache, dependence and migraine chronification Patients who experience attacks that would benefit from non-oral treatment • Presence of nausea, vomiting (29% of all patients), gastroparesis, which delays absorption of oral medications, and dysphagia • Severe attacks • Rapidly progressing attacks • Non-oral treatments may currently be under-utilized, as many patients dislike injectable treatments and liquid nasal sprays (dueto bad taste, drip out, propensity to cause nausea, etc.) Patients who experience difficult-to-treat or long-duration attacks, e.g., menstrually associated attacks Patients who experience frequent attacks • Frequent use of triptans, NSAIDs, opioids, barbiturates and other treatments poses risk of Medication Overuse Headache • DHE is thought to have a low risk for causing Medication Overuse Headache 25

STS101 commercial opportunity and positioning Headache specialists view STS101 as having further utility in additional patient and attack types Medication Overuse Headache • ~1-2% population prevalence • DHE administered by injection is commonly used to treat Medication Overuse Headache Patients requiring backup or rescue medication • “Backup and rescue medication should be available in case the initial treatment fails” • ~4 million emergency room visits for migraine each year in the U.S. Status migrainosus (migraine duration >72h, despite treatment) • Estimated incidence >500,000 per/year in U.S. • DHE administered by injection is commonly used to treat status migrainosus Sources: Silberstein, Nat Clin Pract Neuro 2008; Burch et al., Headache 2021; VanderPluym et al, Neurology 2021; Diener et al.,Lancet Neurol 2019 26

STS101 brand development Activities completed • STS101 tradename established Conditionally approved by FDA Tested with HCPs Trademark application filed Web domains secured • Branding Brand positioning, personality, character and hallmark work, including logo and colors, completed 27

STS101 clinical development 28

STS101 clinical trial program Required by FDA to support ST101 clinical trials Trial Objective NDA filing and approval? Key clinical trials conducted with investigational product incorporating to-be-marketed nasal delivery device Phase 1 PK trial STS101-006 Establish PK bridge to listed products Yes ASCEND Phase 3 open-label, * STS101-003 Characterize local nasal toxicity of STS101 Yes long-term safety trial SUMMIT Phase 3 double-blind, Establish product-specific efficacy results to include in STS101-007 No placebo-controlled efficacy trial Section 14 of prescribing information Supportive clinical trials conducted with investigational product incorporating first-generation nasal delivery device Phase 1 PK trial STS101-001 Establish PK bridge to listed products No EMERGE Phase 3 double-blind, Establish product-specific efficacy results to include in STS101-002 No placebo-controlled efficacy trial Section 14 of prescribing information *Study initiated in August 2020 with STS101 incorporating 1st-generation device (Mk1); transition to STS101 incorporating 2nd-generation, to-be-marketed device (Mk2) completed in 1H 2021 29

Phase 1 PK trial STUDY STS101-006 Objective: Establish PK bridge to listed products, MIGRANAL and D.H.E. 45 Required by FDA to support STS101 NDA and potential approval via 505(b)(2) regulatory pathway Investigational product incorporates to-be-marketed nasal delivery device 30

STS101 5.2 mg achieved target PK profile in 2021 Ph1 trial (STS101-006) PK profile optimized to maximize efficacy while minimizing sideeffects 2021 Ph1 PK study with 2nd generation delivery device Established PK bridge to listed products (MIGRANAL and D.H.E. 45) required for 505(b)(2) pathway Mean DHE plasma concentration (pg/mL) approval Rapidly achieved and sustained target plasma concentrations with low variability PK profile predicted to translate to robust and sustained efficacy Favorable safety & tolerability—STS101 5.2 mg demonstrated low AE rates—Incrementally higher AE rates observed with STS101 dose Time after dosing (0-12 hours) strengths > 5.2 mg (e.g., nasal congestion, nausea and STS101 PK variability less than DHE liquid nasal spray and comparable to MAP0004* vomiting) 31 *MAP0004 is unapproved, discontinued oral pulmonary-route DHE product that demonstrated positive results in large Ph3 trial

ASCEND Phase 3 open-label, long-term safety trial STUDY STS101-003 Objective: Characterize local nasal toxicity profile of STS101 Required by FDA to support STS101 NDA and potential approval via 505(b)(2) regulatory pathway Study initiated in August 2020 with STS101 incorporating 1st-generation device; transition to STS101 incorporating 2nd-generation, to-be-marketed device completed in 1H 2021 32

ASCEND long-term, open-label safety trial objectives and design (Study STS101-003) • PRIMARY OBJECTIVES:—Assess safety and tolerability of STS101 5.2 mg over 6 and 12 months—Satisfy FDA requirement to characterize local nasal toxicity of STS101 in ≥150 subjects who treat ≥2 migraine attacks/month for at least 6 months; and potentially ≥50 subjects who treat ≥2 migraine attacks/month for at least 12 months.—FDA: If no safety signals of concern are seen in the 6-month data, one-year data may not be required. • SECONDARY OBJECTIVE: assess the efficacy of STS101 over time • OPEN-LABEL DESIGN—>480 subjects who treat their migraines with STS101 on an as-needed basis for us to ~18 months—May be on stable regimen of up to two preventive treatments (including anti-CGRP mAb or gepant)—Optional second dose of STS101 allowed to treat each migraine attack, subject to maximum of 12 doses/month—Company proactively discontinued subjects who did not have sufficient attacks to contribute toward attainment of exposure requirements • Study initiated in August 2020 with STS101 incorporating 1st-generation device; transition to STS101 incorporating 2nd-generation, to-be-marketed device completed in 1H 2021—Satsuma intends to seek marketing approval for and commercialize STS101 incorporating 2nd-generation device 33

ASCEND is one of the largest-ever trials conducted with a DHE product 482 subjects enrolled, with 446 subjects using ≥10,000 doses of STS101 to treat ≥8,000 attacks for up to ~18 months—~19% of subjects discontinued by Satsuma due to insufficient number of attacks—~100 active subjects in trial as of June 30, 2022cut-off date for analysis STS101 incorporating 2nd generation, to-be-marketed device Mk2): (STS101—166 subjects treated ≥2 migraine attacks/month for ≥6 months, exceeding FDA requirement for NDA submission and potential approval—344 subjects used ≥6,900 doses of STS101Mk2 to treat ≥5,500 attacks for up to ~18 months (STS101Mk2 safety population)—172 subjects used STS101Mk2 exclusively to treat 1,932 attacks—STS101Mk2 safety population had migraine history and typical pre-study migraine symptoms indicative of severe attacks: Migraine history Symptoms of typical attacks before study 18.5 yrs (±11 years) mean time since onset 74% severe pain (24% moderate; 2% mild) 5.5 moderate / severe attacks per month 97% photophobia 7.5 headache days per month 95% phonophobia 85% nausea Mean HIT-6 (Headache Impact Test) score: 65 (scores >60 indicate “severe impact” and high disability) 34

STS101Mk2 demonstrates favorable safety and tolerability profile • No clinically relevant systemic safety findings (vital signs, EKGs, labs), or local nasal tolerability or safety findings • AEs were typically mild (82.7%) and transient • Low rates of treatment-related nausea and vomiting • Only 4.1% of subjects cited AE as reason for discontinuing trial Related adverse events in >2% of N (%) of subjects reporting AE at least once % of attacks with AE subjects (344 subjects) (5,571 attacks) Nasal discomfort 38 (11.0) 338 (6.1) Dysgeusia 26 (7.6) 154 (2.8) Nasal congestion 15 (4.4) 198 (3.6) Nasal pain 10 (2.9) 40 (0.7) Rhinorrhea 8 (2.3) 45 (0.8) Related nausea and vomiting Nausea 6 (1.7) 9 (0.2) Vomiting 4 (1.2) 6 (0.1) Source: STS101-003 Interim Analysis Data Cut June 30, 2022; reported data is from use of 2nd-generation device 35

STS101Mk2 demonstrated robust efficacy despite treated attacks having high rates of symptoms predictive of poor response Among the 172 subjects who used STS101Mk2 exclusively to treat their attacks: Exploratory efficacy endpoints % of all treated Treated attacks had high rates of attacks (n=1,932) symptoms predictive of inadequate response to treatment Freedom from pain by 2h post-treatment 34.2 Freedom from most-bothersome-symptom 53.4 by 2h post-treatment Baseline symptom % of attacks Severe pain 47 Subjects successfully treated most attacks with a Photophobia 97 single dose of STS101 Phonophobia 94 • No second dose of STS101 used within 48h of 1st dose in >81% of treated attacks Nausea 65 • No rescue medications used within 48h of STS101 in >94% of treated attacks 36

% of attacks in which Pain Freedom achieved (among 172 subjects who exclusively used STS101MK2 to treat 1,932 attacks) Pain freedom over time (%) 86 87 65 34 12 1 HR 2 HR 4 HR 24 HR 48 HR Source: STS101-003 NDA Interim Analysis June 30, 2022; Expansion cohort only: 172 subjects with data from 1932 treated attacks 37

% of attacks in which freedom from MBS achieved (among 172 subjects who exclusively used STS101MK2 to treat 1,932 attacks) Most bothersome symptom freedom over time (%) 91 90 79 53 27 1 HR 2 HR 4 HR 24 HR 48 HR Source: STS101-003 NDA Interim Analysis June 30, 2022; Expansion cohort only: 172 subjects with data from 1932 treated attacks 38

Low use of rescue medication and allowed 2nd STS101 dose in most attacks (among 172 subjects who exclusively used STS101MK2 to treat 1,932 attacks) Parameter 24 hrs 48 hrs % Attacks % Attacks Use of rescue medication 3.9 5.4 Second dose of STS101 18.5 18.6 Source: STS101-003 NDA Interim Analysis June 30, 2022; Expansion cohort only: 172 subjects with data from 1932 treated attacks 39

ASCEND subjects reported consistently favorable impressions of STS101 and its antimigraine effects over time Subject impressions of STS101 after 3, 6 & 12 months of use 40 n=289-290 at month 3; 220 at month 6; 122 at month 12

ASCEND subjects reported consistently favorable impressions of STS101 and its antimigraine effects over time Subject impressions of STS101 antimigraine effects after 3, 6 & 12 months of use 41 n=283-284 at month 3; 216 at month 6; 120-121 at month 12

SUMMIT Phase 3 double-blind, placebo-controlled, efficacy trial STUDY STS101-007 Objective: Establish product-specific efficacy results for inclusion in Section 14 of prescribing information NOT required by FDA to support STS101 NDA and potential approval via 505(b)(2) regulatory pathway Investigational product incorporates to-be-marketed nasal delivery device (Mk2) 42

SUMMIT is the largest-ever trial of any DHE product and was conducted in accordance with current migraine trial design, data analysis and quality standards Screening Randomization & treatment End-of-study visit up to 30 days 56 days Within 10 days of treatment 1:1 randomization STS101 5.2 mg* R End-of-study visit Placebo* 1,591 subjects randomized Designed per published FDA guidance for developing acute treatment of migraine drugs (Feb 2018) Key inclusion criteria: Treat single migraine of attack of moderate or severe pain intensity Key secondary endpoints • 18-65 years of age Co-primary endpoints: • % Pain-free and MBS-free over time • ≥ 1-year history of • % free from headache pain at 2h post-treatment • Pain relief at 2h and over time migraine • % free from most bothersome symptom at 2h post-treatment • Use of rescue medication • 2-8 migraines per month (from among photophobia, phonophobia or nausea) • Sustained 2-24h pain-and MBS- • No significant CV disease freedom or risk factors 43 * All investigative product utilized improved, second-generation nasal delivery device (“Mk2”)

Endpoint definitions Pain Freedom and Pain Relief Patients report pain severity in electronic diary on a 4-point scale 0 1 2 3 No Pain Mild Pain Moderate Pain Severe Pain SUMMIT subjects treated migraine attacks with Moderate or Severe Pain (i.e., rated as a “2” or “3”) immediately prior to treatment Pain free: Subject reports No Pain (“0”) at time point, i.e., a 2-or 3-point change Pain relief: Subject reports Mild Pain (“1”) or No Pain (“0”) at time point, i.e., a 1-, 2-or 3-point change (Note that change from “Severe Pain” to “Moderate Pain” DOES NOT qualify as a Pain Relief response) Most Bothersome Symptom Immediately prior to treatment, SUMMIT subjects declared their “Most Bothersome Symptom” from among Photophobia, Phonophobia or Nausea MBS-free: the Most Bothersome Symptom that subject declared immediately prior to treatment is no longer present 44

Subject disposition STS101 Placebo Randomized 796 795 Modified Intent-to-Treat* 716 708 Safety** 731 729 *Subject treated qualifying migraine attack with study medication and has at least 1 post-treatment diary entry **Subject used study medication 45

Subject demographics & migraine history (mITT population) Subjects’ demographics and migraine history were representative of typical migraine patient population STS101 Placebo Age (mean; SD) 38.2 yrs (11.4) 38.9 yrs (11.5) Gender (% M/F) 21/79 20/80 Race (%) White 82.5 81.4 African American 12 13.7 Asian 3.5 3.4 Other 2.0 1.5 BMI (mean; kg/m2) 27.7 27.2 Years since onset (mean; SD) 16.2 (11.3) 16.9 (11.4) Self-reported migraines/month and headache days/month during 90 days prior to screening visit # of moderate/severe migraines (SD) 4.5 (1.7) 4.5 (1.7) # of headache days (SD) 6.9 (2.7) 6.9 (3.0) Subjects on prevention medication at randomization (%) 10.2 10.2 46

Characteristics of treated migraine attacks (mITT population) High proportion of SUMMIT subjects had pre-treatment attack characteristics indicative of difficult-to-treat and long-duration attacks that are poorly responsive to treatment Symptoms just before treatment STS101 Placebo (% of subjects with symptom) Moderate headache pain / severe headache pain 61.6 / 38.4 63.4 / 36.6 Nausea 69 68 Photophobia 95 97 Phonophobia 91 91 Aura 50 50 Allodynia* 63 63 *Allodynia was considered present if subject had 2 positive responses in 6 question allodynia questionnaire immediately beforestudy drug administration Sources: Ashkenazi 2007; Tepper 2011; Barbanti et al., Cephalalgia 2016 47

STS101 was numerically superior to, but not statistically different than placebo at 2h post-treatment on co-primary endpoints STS101 Placebo STS101 Placebo (n=716) (n=708) Difference p-value (n=701) (n=699) Difference p-value 20.4% 17.5% 2.9% 0.1661 37.8% 32.9% 4.9% 0.0552 1. MBS: Most-bothersome symptom from among photophobia, phonophobia or nausea declared by subject at time of treated attack 48 2. Subjects who took study medication, entered efficacy data at any timepoint, but did not report data at 2 hr were imputed to be treatment failures

STS101 (single dose) demonstrated sustained effects on Pain Freedom and Freedom from MBS endpoints • STS101 (single dose) demonstrated robust and sustained anti-migraine efficacy, but did not achieve statistical significance on pre-specified co-primary endpoints of % Free from Pain and % Free from Most-Bothersome Symptom* (MBS) assessed at two hours post-treatment • Numerical separation from placebo as early as 1h post-treatment (% Free from MBS) • Statistically superior (p<0.001) to placebo on both co-primary endpoints at all time points from 3h through 48h Co-primary endpoints assessed at 2h p=0.0552 p=0.0002 Co-primary endpoints assessed at 2h p=0.1661 p=0.0009 Subjects who did not report data at a timepoint or who used any rescue medication prior to timepoint were imputed to be treatment failures 49 *from among photophobia, phonophobia or nausea

SUMMIT Phase 3 efficacy trial secondary endpoint summary ✓STS101 demonstrated robust and sustained anti-migraine effects across key secondary endpoints, including those considered clinically relevant and recommended for assessment in efficacy trials by the FDA and/or IHS guidelines* IHS guidelines? FDA guidance? Secondary endpoint p-value ✓ ✓ Pain relief at 2h 0.0017 at 2h & stat sig at all timepoints thru 48h ✓ ✓ Sustained pain-free 2-24h1 0.0479 ✓ ✓ No use of rescue medication within 24h and 48h ≤0.0001 Sustained freedom from MBS from 2-24h1 and 2-48h1 0.0018 / 0.0082 Sustained relief from pain from 2-24h1 and 2-48h1 0.0001 / 0.0006 ✓ Total freedom from migraine2 (pain and all symptoms) 0.0137 at 3h & stat sig at all timepoints thru 48h ✓ ✓ Freedom from nausea 0.0039 at 3h & stat sig at all timepoints thru 48h ✓ ✓ Freedom from photophobia 0.0109 at 3h & stat sig at all timepoints thru 48h ✓ ✓ Freedom from phonophobia 0.0089 at 3h & stat sig at all timepoints thru 48h ✓ Time to pain freedom Median time to pain freedom reduced by ~48%(p<0.0001) 1 with no relapse or use of rescue medications; 2freedom from pain, photophobia, phonophobia & nausea ✓STS101 showed effects in difficult-to-treat attacks, e.g., attacks with allodynia and menstruallyassociated attacks ✓STS101 exhibited a favorable safety and tolerability profile, with low rates of local nasal adverse effects and minimal nausea or vomiting * FDA Guidance, Migraine: Developing Drugs for Acute Treatment, February 2018 50 * Diener et al., Guidelines of the International Headache Society for controlled trials of acute treatment of migraine attacks in adults: FourthEdition, Cephalalgia, 2019

STS101 (single dose) relieved migraine pain and enabled subjects to achieve Total Migraine Freedom • Pain relief—Numerical separation vs placebo by 1.5h post-treatment—Statistically significant (p=0.0017) at 2h post-treatment and at all subsequent timepoints through 48h • TOTAL MIGRAINE FREEDOM = Free from Pain, Photophobia, Phonophobia and Nausea—Statistically significant at 3h post-treatment and at all subsequent timepoints through 48h p=0.0017 p=0.082 p=0.0137 * Denotes p<0.05 Subjects who did not report data at a timepoint or who used any rescue medication prior to timepoint were imputed to be treatment failures 51

STS101 showed effects in difficult-to-treat attacks* • Attacks with allodynia—Lipton et al., Headache 2017: “Because personswithallodynia were likely to have inadequate responses across a range of medications (triptans, NSAIDs, opioids, barbiturates, ergots) there is an unmet need for treatment of patients with allodynia that merits further study.” • Menstrually-associated attacks—IHS acute treatment of migraine controlled trial guidelines: “Migraine attacks occurring in association with menstruation are generally noted to be severe, of long duration, and associated with high relapse rates.” Attack type / symptom and endpoint p-value Attacks with allodynia at time of treatment Free from Pain at 4h (and all timepoints thereafter) 0.022 (at 4h) Free from MBS at 4h (and all timepoints thereafter) <0.0001 (at 4h) Menstrually-associated attacks Free from Pain at 3h (numerical superiority 2-48h; stag sig 3-12h) 0.019 Free from MBS at 2h (numerical superiority 15min-48h; stag sig 3-12h) 0.029 * Burstein et al., Ann Neurol 2004; Lipton et al, Headache 2017; Lainezet al., Pat Rel Outcome Measures 2013; Diener et al., Neurology 2004; Diener et al., Cephalalgia 2008; Martelletti et al., Exp Rev Neurotherapeutics 2019; Diener et al., Cephalalgia 2019 52

STS101 exhibited favorable safety and tolerability profile • Consistent with previous STS101 Placebo clinical trial results, STS101 showed favorable safety & Safety Population (n) 731 729 tolerability profile Treatment-Emergent Adverse Events reported by >1% of subjects • Low incidence of nausea Nasal discomfort 8.3% 1.5% • No treatment-related Dysgeusia 3.7% 0.3% Serious Adverse Events or cardiovascular adverse Nasal congestion 3.1% 0.8% events were predominantly Nausea 1.9% 0.7% • AEs mild (~70%) and transient Throat irritation 1.1% 0.3% Rhinorrhea 1.1% 0.1% 53

SUMMIT trial results in comparison with other DHE products and gepants 54

STS101 efficacy in SUMMIT trial compares favorably with efficacy of approved DHE products STS101 Endpoint MIGRANAL TRUDHESA D.H.E. 45 SUMMIT trial Pivotal Statistically significant vs placebo? study 2h 4h 1 ✓ FDA finding of * ✓* effectiveness not Pain relief ✓ 2h* -48h* 2 ✗ ✓* supported by No product- results from any 3 ✗ ✓* specific controlled trial 4 ✗ ✗ efficacy data for efficacy FDA review found it a striking feature of from Pain freedom ✓ 3h* -48h* all trials in NDA [n=13] that MIGRANAL controlled No monotherapy, attenuatedattacks in both pain intensity trial; same as placebo-Total Migraine Freedom ✓ 3h* -48h* and duration of symptoms, but did not MIGRANAL by controlled trials abort attacks reference ever conducted with D.H.E 45 (or MBS freedom ✓ 3h* -48h* FDA review found effects on secondary any equivalent symptoms to be inconsistent across trials product) Rescue medication use ✓ 21.8%* ~50-56%* within 24h of dosing *Indicates statistically significant vs placebo, for SUMMIT at / through timepoint (efficacy self-reported by SUMMIT subjects atat 0.5, .75, 1, 1.5, 2, 3, 4, 6, 12, 24 and 48h post-dose) 55 Sources: D.H.E. 45 FDA DESI review documents; MIGRANAL Summary Basis of Approval

STS101 safety and tolerability compare favorably with approved DHE products STS101 DHE Treatment-emergent AE rates DHE injection SUMMIT / ASCEND trials liquid nasal sprays ~16%(SC) Nausea 1.9% / 4.9% 10% Est. >50% (IV) Vomiting 0.8% / 1.7% 4% ~7% (SC) TRUDHESA: 52.3% Local (nasal) irritative adverse effects 15.5% / 28.8% -na- MIGRANAL: ~30% Nasal discomfort 8.3% / 11.3% 6.8% -na- Dysgeusia / altered taste 3.7% / 7.6% 8% -na- Congestion 3.1% / 4.9% 15% -19.7% -na- Package-related injury / laceration 0% / 0% 1.7% ?? % of subjects who withdrew from open- 4.1% (ASCEND) 6.5% -na- label, long-term safety trial due to TEAE Sources: MIGRANAL and Trudhesa prescribing information; TRUDHESA Summary Basis of Approval; Smith et al., Headache 2021; Winneret al., Arch of Neurol 1996; Kollins et al., AHS 2022 56

As compared with gepantPh3 trials, treated attacks in SUMMIT trial had higher rates of baseline symptoms predictive of poor response to treatment Not reported for gepanttrials Reported at screening visit Source: NurtecSBA, UbrelySBA, Lipton et al., JAMA 2019 57

STS101 achieved absolute Pain-free and MBS-free response rates from 0-2h similar to gepants • Comparison of absolute response rates 0-2h for STS101 / SUMMIT Gepant / Ph3 trials STS101 (SUMMIT), NURTEC and UBRELVY (PI) Pain Free at 2h -Active 20.4% 19.2% – 21.8% Placebo 17.5% 11.8% -14.3% • Gepant trials had lower placebo-response rates MBS Free at 2h -Active 37.8% 35.1% -38.8% Placebo 32.9% 25.2% -27.7% SUMMIT subjects who did not report data at a timepoint or who used any rescue medication prior to timepoint were imputed to be treatment failures Sources: NURTEC and UBRELVY prescribing information; Ubrogepant and Rimegepant Ph3 efficacy trials results (n=5) 58

STS101 demonstrated high absolute response rates for all symptoms despite treated attacks having high rates of baseline symptoms predictive of poor response 59

Regulatory

STS101 and the 505(b)(2) pathway STS101 505(b)(2) strategy relies partially on referenced information, including: • Nonclinical toxicology data (long-term tox, reproductive tox, carcinogenicity studies) • Pharmacology data, including clinical pharmacology study results • Thorough QT study results • FDA’s previous findings of safety and effectiveness for the ”listed drugs”:—MIGRANAL (DHE liquid nasal spray) -approved 1997—D.H.E. 45 (DHE for injection) -originally determined safe by FDA in 1946; determined effective for migraine in early 1970s via DESI review of NDA that contained no controlled clinical studies for efficacy 61

Regulatory strategy, status and timelines Straightforward and precedented path to regulatory approval via 505(b)(2) pathway based on FDA feedback from May 2022 Type B pre-NDA clinical and CMC meetings and two previous Type C meetings ✓FDA agrees that requisite 505(b)(2) scientific bridge to listed products (D.H.E. 45 intramuscular DHE injection and MIGRANAL) appears to have been established via bracketing approach ✓FDA agrees that data from ASCEND long-term, open-label safety trial appear sufficient to support NDA submission and potential approval • In 3 meetings, FDA has consistently indicated that a Phase 3 efficacy trial, such as SUMMIT, is optional and not necessary for approval • Satsuma and its expert regulatory advisors believe there are strong arguments for including SUMMIT trial efficacy results in STS101 prescribing information Status & timelines ✓Completed clinical and CMC pre-NDA meetings in Q2 2022; no issues of concern identified Q1 2023 Q2 2023 Q3 2023 Q4 2023 Q1 2024 Q2 2024 Commercial File NDA NDA approval introduction 62

Based on input from our expert legal-regulatory consultants, we are confident our STS101 regulatory strategy will support NDA filing and potential approval • Satsuma’s longstanding STS101 regulatory strategy has been to seek FDA approval via the 505(b)(2) pathway • In three meetings, including May 2022 pre-NDA meeting, FDA has agreed with our regulatory strategy and indicated STS01 approval requirements could be met by: 1. Establishment of a “pharmacokinetic bridge” to the listed drugs, D.H.E. 45 and MIGRANAL FDA agrees our Ph1 PK trial appears to establish the requisite PK bridge via a bracketing approach 2. Characterizing the long-term nasal toxicity of STS101 via the ASCEND long-term, open-label safety trial FDA agrees results of the ASCEND trial* appear to FDA has already found D.H.E. 45 and MIGRANAL “safe” support NDA filing and may support approval and “effective” and their PK curves bracket STS101; ergo, • FDA has consistently communicated that a Ph3 efficacy FDA should also consider STS101 “effective” and “safe” trial, such as SUMMIT, is NOT REQUIRED for STS101 (with respect to its systemic adverse event profile) approval, but could potentially be included in label * 6-month safety set with second-generation / Mk2 nasal delivery device 63

Based on input from expert legal-regulatory consultants, we believe there is a strong case for including SUMMIT trial efficacy results in the STS101 label Arguments for including SUMMIT efficacy trial results in the MIGRANAL (approved 1997) D.H.E. 45 STS101 label SUMMIT is a large, placebo-controlled trial conducted in Determined FDA review found multiple issues with design accordance with current migraine trial design, data analysis “effective” in early and conduct of trials and quality standards 1970s via DESI SUMMIT co-primary endpoints are a high efficacy bar that no process other DHE product has cleared Pivotal trials (n=4) utilized a “low-efficacy-bar” FDA finding of STS101 demonstrates robust anti-migraine effects that no endpoints, Pain Relief and Reduction in Pain effectiveness not other DHE product has shown in a placebo-controlled trial, Intensity, evaluated at both 2h and 4h post-supported by any including Pain Freedom (3h*); MBS Freedom (3h*) and Total treatment controlled trial for Migraine Freedom (3h*), i.e., the ability to abort attacks Showed inconsistent efficacy on pain and efficacy Migraine trial construct (wait to treat until pain intensity is secondary symptom endpoints across trials moderate or severe) is artificial; in the real world, patients MIGRANAL does not abort migraines There are no clinical are instructed to treat early, when pain is mild trial results in the FDA reviewer: “It is a striking feature of all 2h timepoint for co-primary endpoint assessment is based D.H.E. 45 prescribing studies in this Application [n=13] that the on ethical considerations; postponing use of effective rescue information use of [MIGRANAL] attenuated migraine medications beyond 2h deemed to subject trial participants attacks in both intensity of pain and duration to undue harm of symptoms, but did not abort the attacks.” STS101 SUMMIT trial results provide HCPs and patients with important and relevant information * Time point at which statistically significant effect vs placebo observed 64 Sources: D.H.E. 45 FDA DESI review documents; MIGRANAL Summary Basis of Approval, Diener et al., Cephalalgia 2019

CMC 65

CMC summary Commercial supply chain and commercial-scale manufacturing capability established • Formulation manufacture by world-class CMO • Manufacture of nasal delivery device components (Satsuma owns commercial mold tooling) • Filling, assembly and packaging. (Satsuma owns custom, high-speed, automated manufacturing line that is located at / operated by world-class CMO.) COGS • Low anticipated cost-of-goods Stability • Robust stability program supports long shelf-life with no special storage conditions required Design Verification • All CMC sections of the NDA have been written and reviewed, and all design verification reports are completed • Human Factors program successfully completed 66

Intellectual property and barriers to competitive entry 67

Significant long-term barriers to competitive entry / generics Broad IP estate, with >60 issued and pending patents, reflects innovative nature of STS101 and our drug delivery technologies • Patentscover formulations, dosages, devices, and methods of treatment • 10 issued U.S. patents with estimated last expiration in December 2039 • Ex-U.S.: 13 issued and allowed patents; expect issued and pending STS101 patents to have similar lives as in the U.S. Additional competitive barriers • Know-how and trade secrets related to the STS101 formulation, delivery device, and manufacturing processes • Specialized manufacturing equipment required • Drug-device combinations are challenging to genericize • STS101 is the result of extensive formulation and device R&D over a long period of timeline 68

Competition 69

Impel Pharmaceuticals’ Trudhesa (INP104) DHE liquid nasal spray • Dosage form (liquid solution) and container closure system (vial) identical to MIGRANAL, only difference vs MIGRANAL is nasal delivery device • TRUDHESA nasal delivery device is HFA propellant-powered, single-dose POD device, that Impel claims delivers drug to “upper nasal cavity.” • Impel claims POD device provides superior clinical performance, but FDA states in its review: “The I123 POD device is designed to apply DHE higher in the nasal cavity than typical nasal spray devices (although any clinical advantages to such administration have not been established)” TRUDHESA label reports higher rates of local irritative nasal symptoms (52.3%) vs MIGRANAL (~30%) and high reported rates of congestion as 1 Rx = 4 kits (1 single-use device + 1 vial) AE (15%) WAC price / dose unit: $223.13 • Approved September 2021 based on results from Phase 1 PK and open-label safety trials; no controlled-trials evaluating efficacy conducted • Impel launched with 60-rep field force in Q4 2021 (our competitive intelligence indicates actual rep count was ~46) • Announced field force expanded to 90 reps in July 2022 • Distributed via specialty pharmacy channel that provides home delivery 70

TRUDHESA / INP104: MIGRANAL DHE liquid nasal spray-–delivered with propellant-powered device rather than manual spray pump Nasal Spray Device Parts FDA review: “The I123 POD device is designed to apply DHE higher in the nasal cavity than typical nasal spray devices (although any clinical advantages to such administration have not been established).”* Formulation and vial identical to MIGRANAL – but delivered via single-use, propellant-powered spray device • Hydrofluoroalkane propellant is potent greenhouse gas Complex, multi-step administration procedure Glass Vial Parts • Single-doseproduct requiring vial opening, assembly, priming and administration into both nostrils • Laceration risk from metal band on vial; in Impel Ph3 safety trial, 2-3% of subjects reported ”Package-associated injury.” FDA AE reporting system contains reports of serious lacerations with MIGRANAL Only PK and open-label safety studies conducted; No RCTs • No product-specific efficacy data in label • Impel promotes efficacy results, including post-hoc analyses, from open-label safety trial • Label contains MIGRANAL efficacy data; only 1 of 4 trials show statistically significant pain relief at 2h 71 * Trudhesa Summary Basis of Approval

INP104 PK is similar to MIGRANAL and much lower than STS101 • Whether INP104 exposure is sufficient for robust 2h efficacy is uncertain • Comparative Migranal Cmax and PK PK results from same trial results reported by Impel in INP104 Ph1 PK trial are lowest ever reported for Migranal and much lower than INP104 reported in 14 other Migranal Ph1 PK studies MIGRANAL (Satsuma Ph1 trials) MIGRANAL (Impel Ph1 trial; PK much lower than reported in 13 other MIGRANAL Ph1 trials) 72

INP104 has higher PK variability than STS101 and MAP0004* Similar to MIGRANAL, INP104 exhibits higher PK variability vs STS101 and MAP0004 73 *MAP0004 is unapproved, discontinued oral pulmonary-route DHE product that demonstrated positive results in large Ph3 trial

Trudhesa prescription data to date suggest slow uptake Underlying reasons for slow uptake • Inferior product: poor ease-of-use; large size; complex multi-step administration procedure; messy: drips out ofnose and runs down back of throat • Product may not perform as advertised: poor and inconsistent efficacy similar to MIGRANAL? • PK is only incrementally better than MIGRANAL • No product-specific efficacy results from any randomized, controlled trial • Slow out of the gate: limited pre-commercial activities due to resource constraints • Insufficiently resourced launch • Poor execution $0.577 $1.759 $2.803 $3.082 74 TRUDHESA net sales (millions) reported by IMPEL since launch

Additional non-oral route, late-stage products Competitor Status Comments AMNEAL Pharmaceuticals • NDA filed Q2 2021 • DHE for injection + autoinjector device DHE auto-injector • AMNEAL currently projecting • AMNEAL projects $0.5B addressable market potential launch in 2024 opportunity and $50-100M peak sales Pfizer • NDA filed Q2 2022 • Efficacy profile similar to oral gepants Zavegepant liquid nasal spray • Relatively high rates of dysgeusia reported in pivotal trials (21%) • Higher rate of nausea (vs STS101 in SUMMIT) reported in pivotal trial (4.1%) • Pfizer promotion may help increase awareness of need for non-oral treatments and expand size of non-oral market segment • Analysts project annual sales >$200M by 2030 75

Thank you

Satsuma & Shin Nippon Biomedical Laboratories, Ltd. • Established 1957 • Traded on Tokyo Exchange (Securities code: 2395) • >2,000 employees • Core businesses include preclinical / toxicology and clinical research services (in JV with PPD) • Strong history of innovation 2012 Established WAVE Life Sciences (Nasdaq:WVE) Early 2000s Invented nasal drug delivery platform technology and initiated development of product candidates • Nasal delivery device and powder formulation prototypes • Non-human primate translational PK system • Advanced development of multiple product candidates, including two products evaluated in clinical trials under INDs • Established broad IP portfolio 2016 Established Satsuma Pharmaceuticals as a spin-out focused on developing STS101 for the acute treatment of migraine • Collaboratively developed STS101 formulation with Satsuma • Performed >80 non-human primate PK studies, evaluating >60 formulations • Developed and optimized formulation for PK, favorable “nose feel” with minimal irritation, stability and manufacturability • Provided Satsuma with access to U.S. regulatory dossiers for products advanced through Phase 1 and Phase 2 trials in U.S. under IND • Invested in seed round, Series B, IPO and 2021 PIPE financings and remains a significant stockholder 77

MAP Pharmaceuticals / MAP0004 recap Pulmonary-route DHE product developed by MAP Pharmaceuticals 28% Pain Free @2h vs 10% for placebo Complex & novel product with MAP0004 & STS101 5.2 mg have similar early PK Robust efficacy in large RCT (FREEDOM) manufacturing challenges & Cmax Sources: Allergan Global Medical Affairs, DDI study, STS101-006 PK trial • DHE Particles produced by novel “Supercritical Precipitation” process • Allergan entered into co-promote with MAP Pharmaceuticals and paid $80M in upfront and • Novel, breath-synchronized inhaler milestone payments • Blend of 2 hydrofluoroalkane (HFA) • Allergan acquired MAP for $958M after NDA filing propellants • MAP & Allergan received 3 CRLs for CMC issues prior to Allergan discontinuing • Primeless metering valve • Inhaler “clicks” upon actuation • In effort to address CMC problems, Allergan acquired contract manufacturer, Exemplar, for $20M • 4 doses (8 puffs) per inhaler • No read-through of CMC problems, which included content uniformity in cannister filling process, to STS101 Source: Allergan Global Medical Affairs 78