Infinity Provides Company Update and Reports First Quarter 2017 Financial Results

CAMBRIDGE, Mass., May 9, 2017

"IPI-549 has a number of key attributes that have enabled us to rapidly enroll patients in our ongoing study. It is orally administered, is believed to be the only selective PI3K-gamma inhibitor in clinical development, and has demonstrated a favorable tolerability profile, both as a monotherapy as well as in combination with Opdivo," stated Adelene Perkins, Infinity's chair and chief executive officer. "Additionally, there is a strong body of preclinical translational research supporting the program demonstrating that selectively targeting PI3K-gamma with IPI-549 reprograms macrophages from a pro-tumor to an anti-tumor phenotype and is able to help overcome resistance to checkpoint inhibition, representing a unique and potentially transformative approach within immuno-oncology."

"Our dose-escalation phases evaluating IPI-549 alone and with Opdivo are ongoing, and we are on track to initiate the expansion phases in the second half of the year. The expansion phases will allow us to generate additional clinical data from monotherapy treatment as well as from the combination of IPI-549 and Opdivo in specific types of solid tumors. We are pleased with the data we recently presented at the AACR Annual Meeting 2017, and we expect to report additional data from this study in the second half of the year," continued Ms. Perkins.

The ongoing Phase 1 study is designed to evaluate the safety, tolerability, activity, pharmacokinetics and pharmacodynamics of IPI-549 as a monotherapy and in combination with Opdivo in approximately 175 patients with advanced solid tumors. The study includes four phases, or modules: monotherapy dose escalation, combination therapy dose escalation, monotherapy expansion, and combination therapy expansion. The combination expansion module will include multiple cohorts designed to evaluate IPI-549 in patients with specific types of cancer, including patients with non-small cell lung cancer (NSCLC), melanoma, and squamous cell carcinoma of the head and neck (SCCHN) whose tumors show initial resistance or subsequently develop resistance to immune checkpoint blockade therapy. There is a great need for additional treatment options for the growing number of patients living with these cancers, which account for more than 17 percent of all new cancer cases in the U.S.^1,2

Recent Developments

• Dose-escalation modules of Phase 1 study of IPI-549 ongoing: Infinity reported today that it has completed an analysis of a cohort of patients who received IPI-549 40 mg QD and has begun enrolling patients in a cohort to evaluate IPI-549 60 mg QD. The company expects to complete the monotherapy dose-escalation module in the first half of the year and subsequently initiate patient enrollment in the monotherapy expansion module in the second half of 2017.
  
  Infinity also reported today that it is continuing to evaluate data from the dose-escalation cohort evaluating IPI-549 30 mg QD in combination with Opdivo. The company expects to complete the combination dose-escalation module and initiate the combination expansion module in the second half of 2017.
  
  
• Updated Phase 1 clinical data presented at AACR Annual Meeting 2017: New Phase 1 data from a March 20, 2017, data cutoff were presented during a poster session at the AACR Annual Meeting 2017. The presentation included data from 15 evaluable patients who received monotherapy doses of IPI-549 ranging from 10 mg to 40 mg QD and six evaluable patients who received IPI-549 20 mg QD in combination with Opdivo.
  
  Data from the monotherapy dose-escalation module demonstrated that IPI-549 treatment was well tolerated. Among the 15 evaluable patients, no dose limiting toxicities or serious drug-related side effects occurred, and no side effects led to treatment discontinuation or dose reduction. The PK and PD properties of IPI-549 appeared favorable, with near-complete and sustained inhibition of PI3K-gamma at doses at or above 20 mg QD, supporting once daily dosing of IPI-549.
  
  Preliminary data from the combination dose-escalation module evaluating 20 mg IPI-549 in combination with Opdivo demonstrated that the treatment regimen was well tolerated and did not result in new or unexpected side effects relative to the known safety profile of each treatment when administered as monotherapy. Among the six evaluable patients, no dose limiting toxicities or serious drug-related side effects occurred, and no side effects led to treatment discontinuation. The PK profile of IPI-549 in combination with Opdivo appeared favorable and suggested that Opdivo does not affect the PK properties of IPI-549.
  
  
• Rationale for targeting PI3K-gamma and preclinical data for IPI-549 presented at AACR Annual Meeting 2017: Jeffery Kutok, M.D., Ph.D., Infinity's chief scientific officer, presented the rationale for targeting PI3K-gamma during an educational session at the AACR Annual Meeting 2017. In contrast to the other three major PI3K isoforms, PI3K-gamma is highly expressed in tumor-associated macrophages and plays an important role in the pro-tumor function of these cells. Infinity's scientists designed IPI-549 to be not only a very potent but also a highly selective PI3K-gamma inhibitor, and it has greater than 100-fold selectivity for PI3K-gamma over the other major PI3K isoforms.
  
  During the educational session, Dr. Kutok also summarized the preclinical rationale for targeting PI3K-gamma previously reported in two publications in Nature.^3,4 Preclinical research has demonstrated that blockade of PI3K-gamma signaling by treatment with IPI-549 results in a transcriptional reprogramming of macrophages. This reprogramming shifted macrophages in the tumor microenvironment from the M2, or pro-tumor phenotype, to the M1, or anti-tumor phenotype, increased the number and activity of anti-tumor T cells that attack the tumor and also increased the production of pro-inflammatory cytokines.
  
  Preclinical data from multiple solid tumor models demonstrated that IPI-549 was active as a monotherapy and that IPI-549 administered in combination with checkpoint inhibition led to enhanced activity compared to either treatment alone. Additionally, preclinical data demonstrated that M2, pro-tumor macrophages are associated with resistance to checkpoint inhibitor monotherapy and that treatment with IPI-549 in combination with checkpoint inhibitors is able to overcome this resistance by reprogramming macrophages from the M2, pro-tumor phenotype to the M1, anti-tumor phenotype. Taken together, these preclinical data demonstrate that PI3K-gamma plays a key role in the immuno-suppressive tumor microenvironment, help to further elucidate the mechanism of action for IPI-549 and provide a strong rationale for the ongoing Phase 1 study of IPI-549.

First Quarter 2017 Financial Results

• At March 31, 2017, Infinity had total cash, cash equivalents and available-for-sale securities of $75.4 million, compared to $92.1 million at December 31, 2016. Cash used for operating activities during the first quarter of 2017 included $5.2 million of payments related to the company's 2016 restructuring activities.
• Infinity did not record any revenue during the first quarter of 2017. Revenue for the first quarter of 2016 was $9.3 million, all of which related to Infinity's previous collaboration agreement with AbbVie Inc.
• Research and development (R&D) expense for the first quarter of 2017 was $4.0 million, compared to $39.2 million for the same period in 2016. The decrease in R&D expense was primarily related to a decrease in clinical development expenses for duvelisib in addition to the company's 2016 restructuring activities.
• General and administrative (G&A) expense was $6.4 million for the first quarter of 2017 compared to $10.8 million for the same period in 2016. The decrease in G&A expense was primarily due to the company's 2016 restructuring activities.
• Net loss for the first quarter of 2017 was $10.5 million, or a basic and diluted loss per common share of $0.21, compared to a net loss of $40.7 million, or a basic and diluted loss per common share of $0.82, for the first quarter of 2016.

Cash and Investments Outlook
Infinity's 2017 financial outlook remains as follows: