Infinity Pharmaceuticals : SABCS Investor Presentation

Eganelisib

First‐in‐Class PI3K‐ Inhibitor Targeting

Immune Suppressive Myeloid Cells in

Metastatic Triple‐Negative Breast Cancer

December 9, 2020

Forward-Looking Statements

This presentation contains forward-looking statements within the meaning of The Private Securities Litigation Reform Act of 1995. Such forward- looking statements include those regarding the company's expectations about: the therapeutic potential of PI3K-gamma selective inhibition and eganelisib, alone and in combination with other therapies; clinical trial plans, progress and enrollment projections; plans to present data; and the company's ability to execute on its strategic plans. Such statements are subject to numerous important factors, risks and uncertainties that may cause actual events or results to differ materially from the company's current expectations. For example, there can be no guarantee that eganelisib will successfully complete necessary preclinical and clinical development phases or that any positive developments with eganelisib will result in stock price appreciation. Management's expectations and, therefore, any forward-looking statements in this presentation could also be affected by risks and uncertainties relating to a number of other factors, including the following: Infinity's results of clinical trials and preclinical studies, including subsequent analysis of existing data and new data received from ongoing and future studies; Infinity's ability to obtain, maintain and enforce patent and other intellectual property protection for eganelisib; the content and timing of decisions made by the U.S. FDA and other regulatory authorities; Infinity's ability to obtain and maintain requisite regulatory approvals and to enroll patients in its clinical trials; unplanned cash requirements and expenditures; and development of agents by Infinity's competitors for diseases in which Infinity is currently developing or intends to develop eganelisib. These and other risks which may impact management's expectations are described in greater detail under the caption "Risk Factors" included in Infinity's annual report and quarterly reports filed with the Securities and Exchange Commission (SEC), and other filings filed by Infinity with the SEC, available on the company's website at www.infi.com. Any forward-looking statements contained in this presentation speak only as of the date hereof, and Infinity expressly disclaims any obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise. Infinity regularly uses its website to post information regarding its business, product development programs and governance. Infinity encourages investors to use www.infi.com, particularly the information in the section entitled "Investors/Media," as a source of information about Infinity. References to www.infi.com in this presentation are not intended to, nor shall they be deemed to, incorporate information on www.infi.com into this presentation by reference.

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Today's Agenda

Eganelisib Introduction

Adelene Perkins, Chair & CEO, Infinity Pharmaceuticals

TNBC Evolving Standard of Care and

Eganelisib Early Signals of Activity in TNBC

Brian Schwartz, MD, Consulting Chief Physician, Infinity Pharmaceuticals

MARIO-3 Initial Results

Erika Hamilton, MD, Medical Oncologist & MARIO-3 Lead Investigator, Tennessee Oncology

Eganelisib Ongoing Development in TNBC

Adelene Perkins

Q&A Discussion

Erika Hamilton, MD; Brian Schwartz, MD; Adelene Perkins

Wrap Up

Adelene Perkins

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Eganelisib: First-in-Class, Oral and Selective Inhibitor of PI3K-

PI3K- has a unique pattern of expression and biological function

	PI3K-			PI3K-α		PI3K-β		PI3K-δ
	Highly expressed in		Ubiquitous		Ubiquitous		Highly expressed in
	TAMs, MDSCs,	endothelial								B cells and T cells
			vs
	cells
	Macrophage reprogramming		Mutated in solid tumors		PTEN-deleted solid tumors		B-cell and T-cell activation
	Immune cell trafficking		Insulin signaling		Platelet activation		and function
	Vascular permeability					Insulin signaling		B-cell malignancies

100X Selectivity for PI3K-γ Over Other PI3K Isoforms

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De Henau O et al. AACR 2016. Abstract 554.