Infinity Pharmaceuticals : J. P. Morgan 2021 Corporate Presentation

Eganelisib

First‐in‐Class Immuno‐oncology Therapeutic

Creating Best‐in‐Class I/O Combinations

39th Annual J.P. Morgan Healthcare Conference

January 14, 2021

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; planning for a registration-enabling study in urothelial cancer; financial guidance; 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.

2

Improves Patient Outcomes Over SOC in Areas of High Unmet Need Multiple Data Readouts in 2021

Eganelisib is a first-in-class, oral, small molecule, immuno-oncology therapeutic

Eganelisib addresses fundamental biologic mechanism of immune suppression in cancer

Clinical and translational data presented in late 2020 demonstrate eganelisib patient benefit over standard of care therapies with UC data at ASCO GU Feb '21 and TNBC in 1H & 2H '21

Planning registration-enabling study in urothelial cancer

Wholly owned drug with composition of matter IP through 2034

3

Infinity 2021 Milestones

		PHASE 1	PHASE 1B	PHASE 2	Late-2020 & 2021 MILESTONES
MARIO-275 in Collaboration with BMS
					Data at ASCO GU Feb.11, 2021
Global, randomized controlled study of eganelisib combination with Opdivo® I/O Naïve 2nd-Line Urothelial Cancer
Planning Registration-Enabling Study

MARIO-3 in Collaboration with

Roche/Genentech

Front-LineTriple-Negative Breast Cancer (TNBC) eganelisib combination with Tecentriq® and Abraxane®	Data Presented at SABCS Dec 2020
Updated Data 1H & 2H 2021

Arcus Biosciences Collaboration
		Data Presented at SABCS Dec 2020
Triple-Negative Breast Cancer (TNBC) eganelisib combination with etrumadenant and Doxil®
Enrollment Ongoing

MARIO-1 in Collaboration with BMS

Checkpoint inhibitor refractory Melanoma & SCCHN eganelisib combination with Opdivo®

Data Presented at SITC Nov 2020

4