Alpine Immune Sciences : Corporate Presentation

Leading the Next Evolution of Immunotherapies

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Forward Looking Statements

This presentation contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, Section 21E of the Securities Exchange Act of 1934 and the Private Securities Litigation Reform Act of 1995. These forward- looking statements are not based on historical fact and include statements regarding Alpine's platform technology, potential therapies, potential milestone and royalty payments, future development plans, clinical and regulatory objectives and the timing thereof, expectations regarding the sufficiency of cash to fund operations through 2023, expectations regarding the plans of its collaborators, expectations of future collaborations, and expectations regarding the potential efficacy and commercial potential of Alpine's and its collaborator's product candidates. Forward-looking statements generally include statements that are predictive in nature and depend upon or refer to future events or conditions, and include words such as "may", "will", "should", "would", "expect", "plan", "intend", and other similar expressions among others. These forward-looking statements are based on current assumptions involving risks, uncertainties, and other factors that may cause actual results, events, or developments to be materially different from those expressed or implied by such forward-looking statements. These risks and uncertainties, many of which are beyond our control, include, but are not limited to: Alpine's programs may not advance into the clinic or result in approved products on a timely or cost-effective basis or at all; Alpine may not achieve additional milestone payments pursuant to its collaborations; the impact of competition; adverse conditions in the general domestic and global economic markets; as well as the other risks identified in our filings with the Securities and Exchange Commission. These forward-looking statements speak only as of the date hereof, Alpine undertakes no obligation to update forward-looking statements, and readers are cautioned not to place undue reliance on such forward-looking statements.

"SIP" and "TIP," and the Alpine logo are registered trademarks or trademarks of Alpine Immune Sciences, Inc. in various jurisdictions.

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Leading the Next

Evolution of

Immunotherapies

With a Highly Productive

Directed Evolution

Platform

Acazicolcept (ALPN-101)

Dual Costimulation (ICOS/CD28) Antagonist

Systemic Lupus

Erythematosus

Phase 2

Partnered with

Davoceticept (ALPN-202)

Conditional CD28

Costimulator and Dual

Checkpoint Inhibitor

Advanced Malignancies

Phase 1/1b

• Monotherapy
• Combination with
  KEYTRUDA®

ALPN-303

Dual B Cell

Cytokine (BAFF/APRIL) Antagonist

Systemic Lupus

Erythematosus and

Other B Cell-Mediated

Diseases

Phase 1

Healthy Volunteer

Phase 2 anticipated mid-2022

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Alpine and Horizon Therapeutics Strategic Partnership

$25M upfront payment and $15M equity investment with up to $1,524M in additional milestones

Transformative Strategic Partnership

Announced December 2021

Exclusive option and licensing agreement or the development and commercialization of up to four preclinical candidates

Validates Alpine's Directed Evolution Platform

Provides funding to accelerate development of Alpine's pipeline

Key Financial

Terms

$25M upfront payment

$15M equity investment at a 25% premium to 30-Day VWAP

$1.52B in total potential milestones at up to $381M per candidate

Tiered royalties of net sales

Partnership

Structure

Alpine responsible to advance candidate molecules to predefined preclinical milestones

Upon preclinical milestones, Horizon will assume responsibility for development and commercialization activities and costs

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Source: Alpine Immune Sciences Form 8-K current report filed with SEC December 16, 2021.

Davoceticept (ALPN-202)

Oncology: Conditional CD28

Costimulator and Dual Checkpoint

Inhibitor

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