Milestone Pharmaceuticals : Corporate Presentation

Company Overview

March 28, 2024

Forward Looking Statement

The Presentation contains forward-looking statements within the meaning of the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, as amended. Words such as ''aim,'' ''anticipate,'' ''assume,'' ''believe,'' ''contemplate,'' ''continue,'' ''could,'' ''design,'' ''due,'' ''estimate,'' ''expect,'' ''goal,'' ''intend,'' ''may,'' ''objective,'' ''plan,'' ''predict,'' ''positioned,'' ''potential,'' ''project,'' ''seek,'' ''should,'' ''target,'' ''will,'' ''would'' (as well as other words or expressions referencing future events, conditions or circumstances) are intended to identify forward-looking statements. These forward- looking statements are based on Milestone's expectations and assumptions as of the date of this Presentation. Each of these forward-looking statements involves risks and uncertainties. Actual results may differ materially from these forward-looking statements. Forward-looking statements contained in this Presentation include statements regarding (i) the design, progress, timing, scope and results of the etripamil clinical trials in PSVT and AFib-RVR, (ii) the potential efficacy, safety and tolerability of etripamil, (iii) the potential of etripamil to deliver a clinically meaningful benefit to patients with PSVT in the home-setting environment and to empower patients to take control of their condition as well as provide value to the healthcare system, (iv) the timing of a potential NDA resubmission, (v) plans relating to commercializing etripamil, if approved, including the geographic areas of focus and sales strategy, (vi) the potential market size and the rate and degree of market acceptance of etripamil and any future product candidates and the implementation of Milestone's business model and strategic plans for its business, etripamil and any future product candidates (vii) Milestone's expected cash runway and (viii) potential royalty payments. Important factors that could cause actual results to differ materially from those in the forward-looking statements include, but are not limited to, the risks inherent in biopharmaceutical product development and clinical trials, including the lengthy and uncertain regulatory approval process, uncertainties as to whether our NDA for etripamil will be approved by the FDA, uncertainties related to the timing of initiation, enrollment, completion and evaluation of clinical trials, including the RAPID and ReVeRA trials, and whether the clinical trials will validate the safety and efficacy of etripamil for PSVT, AFib-RVR, or other indications, among others, as well as risks related to pandemics and public health emergencies, including those related to COVID-19, and risks related the sufficiency of our capital resources and our ability to raise additional capital. These and other risks are set forth in Milestone's filings with the U.S. Securities and Exchange Commission, including in its annual report on Form 10-K for the year ended December 31, 2022, under the caption "Risk Factors", as such discussion may be updated in future filings we make with the SEC including in our Quarterly Report on Form 10-Q for the quarterly period ended September 30, 2023, under the caption "Risk Factors". Except as required by law, Milestone assumes no obligation to update any forward- looking statements contained herein to reflect any change in expectations, even as new information becomes available.

This Presentation contains trademarks, trade names and service marks of other companies, which are the property of their respective owners. Certain information contained in this Presentation and statements made orally during this Presentation relate to or is based on studies, publications, surveys and other data obtained from third-party sources and Milestone's own internal estimates and research. While Milestone believes these third-party studies, publications, surveys and other data to be reliable as of the date of the Presentation, it has not independently verified, and makes no representation as to the adequacy, fairness, accuracy or completeness of, any information obtained from third-party sources. In addition, no independent sources has evaluated the reasonableness or accuracy of Milestone's internal estimates or research and no reliance should be made on any information or statements made in this Presentation relating to or based on such internal estimates and research.

Etripamil is an investigational new drug, which is not approved for commercial distribution in the United States.

Milestone Pharmaceuticals:

Aspiring to Give Patients Control over Common Heart Conditions

Empowering Patients

PSVT

AFib-RVR

Self-Treat Common Arrhythmias

Commercial Launch Preparation

Market Expansion Opportunity

• • Etripamil Nasal Spray: novel calcium channel blocker

  • • NDA resubmission - Mar 2024

    • • End of Phase 2 Meeting expected mid-2024

  • • Type A meeting - Feb 2024

• • Fast-acting, well-tolerated, portable, on-demand

  • • NDA RTF - Dec 2023

    • • FDA provides Phase 3 study guidance - 1Q 2024

• • Shift from Emergency Department to patient self-management

• • Successful Phase 3 - Published in The Lancet

  • • Positive Phase 2 Study - ReVeRA - Published in Circulation AE

• • Experienced leadership driving commercialization

• • AHA Featured Science Presentation - Nov 2023

PSVT = Paroxysmal Supraventricular Tachycardia; AFib-RVR = Atrial Fibrillation with Rapid Ventricular Rate; NDA = New Drug Application; RTF = Refusal to File; AHA - American Heart Association. Citations: Stambler B et al, The Lancet (2023); Camm AJ et al, Circulation: Arrhythmia & Electrophysiology (2023)

PSVT and AFib-RVR Cause Markedly Symptomatic Attacks That Disrupt Patients' Lives

PSVT = Paroxysmal Supraventricular Tachycardia; AFib-RVR = Atrial Fibrillation with Rapid Ventricular Rate

Current Treatment of Acute Attacks in the Emergency Department are Burdensome and Costly

For many patients, physicians and payers:

• • Time-consuming, disruptive

• • Often results in a hospital admission

• • Expensive use of healthcare system resources

Need for simple, fast-acting treatment, reduce trips to ED and calls to physicians

ED = Emergency Department

Etripamil Nasal Spray is a Novel L-type Investigational Calcium Channel Blocker Designed to Treat Episodes Quickly

PSVT and AFib-RVR Populations in the US

PSVT	Atrial Fibrillation
Total Patients (2030)	2.6 Million3	10 Million1
Discharged ED Visits & Hospital Admissions (2016)2	145 Thousand	785 Thousand
Target Addressable Market (2030) Patient Population	1.0-1.6 Million5	~3-4 Million4

Source(s): 1. Colilla et al., Am. J. Cardiol. 2013, 112(8), 1142-1147; Miyasaka et al., Circulation, 2006, 114, 119-125. American Heart Association 2. HCUP ED & Admissions Data (2016), accessed January 2021. 3. Rehorn et al. Journal of Cardiovascular Electrophysiology. 2021 Aug; 32(8): 2199-2206. doi: 10.1111/jce.15109. Epub 2021 Jun 14. 2018 prevalence of 2M anticipated to grow at a CAGR of ~2% 4. Quantitative Survey conducted by Triangle Insights, May 2021, N=250 Clinical Cardiologists, Interventional Cardiologists, and Electrophysiologists. 5. Estimate of TAM (~40%-60% of prevalence) based on internal PSVT patient market research (BluePrint Research Group, n=247) and longitudinal analysis of claims data.

Clinical Pipeline Advancement for Etripamil

PSVT = Paroxysmal Supraventricular Tachycardia; AFib-RVR = Atrial Fibrillation with Rapid Ventricular Rate; NDA = New Drug Application

NDA Resubmitted for Etripamil in PSVT

• • NDA Resubmission - March 2024 ─ Expect standard NDA review period following resubmission

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Resubmission included: ─ Supplementary datasets using a slightly different method to define "treatment-emergent AEs"

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ECG datafiles in additional formats to better enable FDA analyses

• • Type A meeting with FDA - February 2024 ─ Timing of adverse events in question had minimal impact on the overall characterization of the safety profile of etripamil ─ Confirmation of Milestone's approach to address RTF

• • Refusal to File Notice - December 2023 ─ FDA requested clarification about the times recorded for some AEs in the

Phase 3 clinical trials

PSVT = Paroxysmal Supraventricular Tachycardia; NDA = New Drug Application; RTF = Refusal to File; ECG = electrocardiogram; AEs = adverse events

Milestone Corporate Overview

9

Comprehensive Data Supports FDA New Drug Application for Rapid Conversion of SVT Episodes to Sinus Rhythm in Adults

NODE-1	NODE-301	NODE-302 (Ext. of NODE-301)	RAPID	NODE-303
Phase 2	Phase 3	Phase 3	Phase 3	Phase 3
Efficacy (dose finding)	Efficacy	Safety & Efficacy (Repeat Episodes)	Efficacy	Safety (Repeat Episodes)
N = 64	N = 431	N = 169	N=706	N ~450

• • >1,600 Patient Exposures to Etripamil ≥ 70 mg

• • Positive Phase 3 pivotal RAPID trial anchors NDA submission

NDA = New Drug Application; SVT = Supraventricular Tachycardia

NB: NODE-301 and RAPID studies also collected Safety information Source: Milestone Pharmaceuticals Data on File