Pliant Therapeutics : March 2024 Corporate Presentation

Developing Novel Treatments

for Fibrotic Diseases

MARCH 2024

© 2024 PLIANT THERAPEUTICS

Disclaimers

This presentation has been prepared by Pliant Therapeutics, Inc. ("we," "us," "our," "Pliant" or the "Company"). The information set forth herein does not purport to be complete or to contain all of the information you may desire. Statements contained herein are made as of the date of this presentation unless stated otherwise, and this presentation shall not under any circumstances create an implication that the information contained herein is correct as of any time after such date or that information will be updated or revised to reflect information that subsequently becomes available or changes occurring after the date hereof.

This presentation includes forward-looking statements regarding Pliant's proprietary drug candidates, the timing of the start and conclusion of ongoing or planned

clinical trials, including the timing of, and our ability to achieve, anticipated milestones, the sufficiency of our cash, cash equivalents and short-term investments, the timing and outcome of regulatory decisions, future availability of clinical trial data, our collaborations for our product candidates and the maintenance of those collaborations; business and results from operations; and other matters. Actual results could differ materially from those contained in any forward-looking statements as a result of various factors, including without limitation: that Pliant's drug candidates do not advance in development or result in approved products on a timely or cost effective basis or at all; the cost, timing and results of clinical trials; our ability to manage and mitigate the impact of the ongoing COVID-19 pandemic; that many drug candidates that have completed early-stage trials do not become approved drugs on a timely or cost effective basis or at all; the ability to enroll patients in clinical trials; possible safety and efficacy concerns; regulatory developments; the ability of Pliant to protect its intellectual property rights, and unexpected costs, charges or expenses that reduce cash runway. Pliant's pipeline programs are in various stages of pre-clinical and clinical development, and the process by which such pre-clinical or clinical therapeutic candidates could potentially lead to an approved therapeutic is long and subject to significant risks and uncertainties. Pliant undertakes no obligation to update forward-looking statements as a result of new information or otherwise. For a discussion of these and other risks and uncertainties, and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, see the section entitled "Risk Factors" and elsewhere in the Company's most recent Annual Report on Form 10-K and Quarterly Report on Form 10-Q on file with the Securities and Exchange Commission (the "SEC") and our other filings with the SEC.

This presentation also contains estimates and other statistical data made by independent parties and by us relating to market size and growth and other data about our industry. This data involves a number of assumptions and limitations, and you are cautioned not to give undue weight to such estimates. In addition, projections, assumptions, and estimates of our future performance and the future performance of the markets in which we operate are necessarily subject to a high degree of uncertainty and risk.

This presentation concerns drugs that are under clinical investigation and which have not yet been approved for marketing by the U.S. Food and Drug Administration

(the "FDA"). They are currently limited by Federal law to investigational use, and no representation is made as to their safety or effectiveness for the purposes for which they are being investigated.

© 2024 PLIANT THERAPEUTICS

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Pliant - Company Highlights

Industry-Leading Fibrosis Platform

• Inhibition of integrin-mediatedTGF-β activation resulting in antifibrotic effect and shown to be well-tolerated
• Proprietary drug discovery platform - In-house compound library of integrin binders

Programs Targeting High Unmet Medical Need with High-Impact,Near-Term Catalysts

• Bexotegrast (PLN-74809) in development for the treatment of IPF (Phase 2b) and PSC (Phase 2a)
• • In IPF, well tolerated with clear treatment effect at 24 weeks on FVC, lung fibrosis (QLF) and symptoms (cough)
  • In PSC, well tolerated at all doses tested and showed reductions in ELF score and PRO-C3 levels relative to placebo at 12 weeks
• Phase 1 enrolling for PLN-101095 - potential first-in-class small molecule dual αVβ8/αVβ1 inhibitor overcoming ICI resistance

Strong Financial Position

• $495.7M cash1 balance as of December 31, 2023
• Operations funded into second half 2026 together with loan agreement and follow on proceeds

1 - Includes cash, cash equivalents and short-term investments.

© 2024 PLIANT THERAPEUTICS

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Pliant Development Pipeline

Program	Indication	Preclinical		Clinical		Anticipated Milestone	Global
			Rights
			Phase I	Phase IIa	Phase IIb / III

	Idiopathic	BEACON-IPF
Bexotegrast	Pulmonary
Phase 2b trial underway
(PLN-74809)	Fibrosis
Dual selective inhibitor	Primary	24-Week 320 mg
Sclerosing
of αvβ6 /αvβ1
data Mid 2024
Cholangitis
PLN-101095	Solid Tumors	Initial data 4Q 2024
Inhibitor of αvβ8 /αvβ1
PLN-101325	DMD	Regulatory filing
	Other Muscular
	1Q 2024
Anti-integrin mAb of α7β1	Dystrophies

PLN-1474

Selective inhibitor

of αvβ1

MASH-Associated Liver Fibrosis

Phase 2

Ready

© 2024 PLIANT THERAPEUTICS

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Pliant's Integrin Focused Library

Core Platform for Novel Pipeline and Partner Programs

Integrins

• Cell surface receptors that facilitate cell-cell and cell-extracellular matrix adhesion and interaction
• A major path of communication between the extracellular matrix, inflammatory cells, fibroblasts
• Closely involved in signaling processes governing tissue fibrosis

Pliant's Proprietary Library of 10,000+ Integrin Binding Compounds

• Emphasis on optimal pharmacokinetic and selectivity profile
• Broad spectrum of receptor subfamilies including αV integrins, collagen and laminin binders

© 2024 PLIANT THERAPEUTICS

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Fibrosis - A Silent Killer

Idiopathic Pulmonary Fibrosis (IPF) is a lethal pathological process with limited therapeutic options

• 140k patients in the U.S.; 30k-40k new cases/year; 40k deaths/year
• Median survival: 3-5 years - Worse than some common cancers

Primary Sclerosing Cholangitis (PSC) is a progressive inflammatory liver disease resulting in scarring of bile ducts, and cirrhosis

• 30k-45kpatients in the U.S.
• Median survival: 10-12 years without intervention
• Currently no FDA approved therapeutics

https://www.lungsandyou.com/ipf

www.jhmicall.org

© 2024 PLIANT THERAPEUTICS

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Bexotegrast

Understanding the IPF commercial opportunity

CURRENT COMMERCIAL LANDSCAPE IN IPF

• Two marketed agents - Esbriet® and Ofev® with >$4 billion total global revenues in 2022
• Growing market with positive tailwinds
• • Increasing incidence of IPF with aging population
  • New therapies expanding treatable population

CHANGING TREATMENT LANDSCAPE

• Near-termpatent expiry of current treatments
• • Esbriet: First generic sold May 2022
  • Ofev: Loss of US market exclusivity projected in 2025

SIGNIFICANT NEED FOR NEW THERAPEUTIC OPTIONS

• Esbriet and Ofev display modest slowing of IPF progression
• • No improvement on patient quality of life or survival benefit
  • Significant tolerability issues

Esbriet® is a trademark of Genentech/Roche

Ofev® is a trademark of Boehringer Ingelheim International

© 2024 PLIANT THERAPEUTICS

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Bexotegrast - A Potentially Broadly Applicable Antifibrotic

Growing Evidence that Localized TGF-β Inhibition has Potential as Backbone Antifibrotic

• Tissue-specificTGF-β inhibition avoids systemic toxicity while maintaining the antifibrotic effect

Bexotegrast Continues to Demonstrate a Favorable Safety and Tolerability Profile

• Well tolerated in over 700 participants across different patient populations
• No drug-related serious adverse events observed across all trials

Bexotegrast Has Potential to Treat Multiple Fibrotic Diseases

• Clear antifibrotic effect across organ systems and indications
• Bexotegrast can expand into additional pulmonary and liver fibrosis indications

© 2024 PLIANT THERAPEUTICS

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Bexotegrast

A Potential Preferred Treatment Option

ANTI-FIBROTIC MoA

MONO & COMBO TREATMENT

ORAL 1X DAILY DOSING

SAFETY / TOLERABILITY

• Targeted inhibition of fibrotic process- tissue specific inhibition
  of TGF-β
• Dose-dependentFVC benefit in INTEGRIS-IPF study

• Will be evaluated as backbone therapy to be used as monotherapy, and with current treatments
• Flexibility in optimizing therapy for each patient

• Improvement over current multi-pill, multiple times a day options
• No added burden of monthly liver function monitoring

• Well tolerated
• Low frequency of GI-related AEs in monotherapy setting

© 2024 PLIANT THERAPEUTICS

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αvβ6 / αvβ1 Integrins Drive TGF-β Activation in Lung Fibrosis

αVβ6 / αVβ1 integrins promote fibrosis by activating TGF-β	•	TGF-β is a central mediator of fibrosis
	• αVβ6 /αVβ1 integrins activate latent TGF-β in fibrotic tissue
	•	Systemic TGF-β blockade carries toxicity risks

Selectively blocking TGF-β in fibrotic tissues may provide a low risk, effective antifibrotic approach

FIBROSIS

COL1A1

COL3A1

TIMP1

CCN2

ENPP2

…

© 2024 PLIANT THERAPEUTICS

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