Jaren Madden Adelene Q. Perkins - Chairman of The Board, Chief Executive Officer and President Julian Adams - President of Research and Development Lawrence E.

Bloch - Chief Financial Officer, Chief Business Officer, Principal Accounting Officer, Executive Vice President, Treasurer and Secretary

Whitney G. Ijem - JP Morgan Chase & Co, Research Division Joel D.

Sendek - Stifel, Nicolaus & Co., Inc., Research Division M. Ian Somaiya - Piper Jaffray Companies, Research Division John Chung - RBC Capital Markets, LLC, Research Division Lisa Zhang - Goldman Sachs Group Inc., Research Division Jeremiah Shepard - Crédit Suisse AG, Research Division Eun K.

Yang - Jefferies & Company, Inc., Research Division Gregory R. Wade - Wedbush Securities Inc., Research Division

Thank you, Mimi, and good afternoon, everyone. Welcome to today's call to discuss our recent business progress and review our first quarter 2013 financial results.

With me here today are Adelene Perkins, President and Chief Executive Officer; Julian Adams, President of R&D; and Larry Bloch, CFO and CBO. Following our remarks, we will open up the call for Q&A.

The press release issued earlier today details our results and is available on our website at infi.com. Please note that during this call, we may make forward-looking statements about our future expectations and plans, including clinical development milestones, the therapeutic potential of our product candidates and financial projections.

It's possible that our actual results may differ materially from what we project today due to the considerations described in the Risk Factors section of the Form 10-Q for the first quarter of 2013 that we filed this afternoon. While these forward-looking statements represent our views as of today, they should not be relied upon in the future as representing our then current views.

We may update these statements in the future but are not taking on an obligation to do so. Now I would like to turn the call over to Adelene.

Thanks, Jaren. Welcome, everyone, and thank you for joining us on the call today.

This is a very important year for Infinity as we advance our programs towards late-stage development and commercialization. We're continuing to make considerable progress with our lead product candidate, IPI-145, which was recently granted an orphan drug designation by both the FDA and EMA for the treatment of CLL and SLL.

Our Phase I trial of IPI-145 in hematologic malignancies is ongoing, and we've enrolled more than 50 patients in the 5 expansion cohorts that we opened earlier this year at a dose of 75 mg twice a day. Additionally, we announced today that an investigator-sponsored Phase Ib trial evaluating IPI-145 in combination with Rituxan and bendamustine is now open for enrollment.

From our company-sponsored Phase I trial of IPI-145, we will present updated data at the American Society of Clinical Oncology, or ASCO, in June. We have a poster presentation on June 2 and an oral presentation on June 3.

Following our presentation on Monday, June 3, we will host an investor event with -- at ASCO with management and investigators from the Phase I trial, and we look forward to reviewing our data with you in greater detail at that time. Additionally, there will be 3 presentations on data from our Phase I trial of IPI-145 at the International Conference on Malignant Lymphoma, which will be held from June 19 to the 22 in Lugano, Switzerland.

We are also studying IPI-145 in inflammation. Today, we announced that the ASPIRA trial, which stands for Adult Study of PI3 Kinase Inhibition in RA, is open for enrollment.

This is a Phase II double-blind, randomized, placebo-controlled study of IPI-145 in patients with moderate to severe rheumatoid arthritis. We also have an important milestone still ahead this year in our Hsp90 program.

We now expect to report top line data from this study in the second half of the year, and Julian will discuss this trial in more detail. Our goal at Infinity is to build a sustainable, fully integrated biopharmaceutical company, and we believe we have the necessary pieces in place to realize this vision: an experienced team, a solid financial foundation and promising product candidates with worldwide rights to our entire product portfolio.

With these fundamental elements in place, we believe we have the capabilities required to rapidly advance our programs to their next value inflection point. We are also committed to deepening our pipeline.

In addition to our internal discovery efforts, we actively evaluate potential in-licensing opportunities to identify high-value programs where we believe we have the scientific and clinical expertise to expand or accelerate a product candidate's development. In summary, our strong foundation and the magnitude of the opportunities before us positions Infinity well to realize our goal of bringing meaningful new medicines to patients.

Our ability to achieve our mission is driven by Infinity team members, who we refer to as citizen owners. Citizen ownership speaks to the passion and commitment that every person in the company has for our collective effort on behalf of patients and the way in which we work together.

Developing important medicines is constant team endeavor, and our culture of collaboration is one of the reasons we were recently included in the Boston Business Journal's Best Places to Work list for the sixth year in a row. Together, we're looking forward to achieving several important milestones this year, and I look forward to updating you on our continuing progress.

With that, I'll turn the call over to Julian to review our pipeline.

Thank you, Adelene. We're very pleased with the progress we've made in our PI3 kinase and heat shock protein 90 programs over the past few months, and we look forward to sharing data from both of these programs this year.

This afternoon, I will review our pipeline with a focus of IPI-145, our potent PI3 kinase delta/gamma inhibitor. At the ASH meeting last December, we reported encouraging preliminary data demonstrating that IPI-145 was well tolerated and clinically active across a broad range of hematologic malignancies, with activity observed at each dose evaluated.

Earlier this year, we defined the maximum tolerated dose at 75 milligrams BID and initiated 5 additional expansion cohorts at the 75-milligram dose level to broaden our patient experience. With ASCO around the corner, we are entering one of our busiest and one of my favorite times of the year.

Two abstracts describing data from our ongoing Phase I trial of IPI-145 were accepted for presentation. Just to remind you, these are plain vanilla abstracts since they include only the data presented at ASH.

Both presentations at ASCO will incorporate an updated data from the dose escalation phase, the fully enrolled 25-milligram expansion cohort initiated in July of 2012, and newly initiated cohort expansions at 75 milligrams. The first presentation will occur on Sunday, June 2.

It will be a poster on patients with chronic lymphocytic leukemia and small lymphocytic lymphoma or CLL and SLL. We plan to provide updated data on the following: safety, lymphocytosis in terms of both onset and resolution, activity observed in terms of nodal responses and International Working Group criteria responses and pharmacokinetic data.

The second presentation, which will take place on Monday, June 3, will be an oral presentation on patients with lymphoma. Similar to the poster presentation, we will update -- we will provide updated data on tolerability, activity observed in terms of partial and complete responses and pharmacokinetics.

Taken together, we expect the 2 presentations to present data from over 100 patients, with over 60 patients having been treated for at least 2 months, which is the time of the first standardized evaluation, for example, CT scan, PET scan or clinical evaluation. Of these estimated 100 patients, approximately 30 will be included in the CLL/SLL presentation, and the remainder will be included in an oral presentation on lymphoma and other diagnoses.

Looking ahead, we are focused on refining our development plans and registration strategies, which includes planning for both monotherapy and combination trials. We expect to initiate at least 2 new company-sponsored trials in hematologic malignancies this year, and we will provide additional details on our development strategy and patient enrollment when these trials begin.

As Adelene mentioned, an investigator-sponsored trial of IPI-145 is also now underway. This trial, which is being conducted by the Sarah Cannon Research Institute, is a Phase Ib open-labeled dose escalation trial of IPI-145 in approximately 70 patients with B-cell, NHL, CLL and T-cell lymphoma.

The study is designed to evaluate safety, pharmacokinetics and clinical activity of IPI-145 in combination with Rituxan, bendamustine or all 3 therapies. The first -- this first investigator-sponsored trial could help inform the design and potential combination studies in the future and highlights the enthusiasm for 145 that we are seeing from thought leaders.

Beyond hematologic malignancies, there's also strong biological rationale for developing IPI-145 in inflammation. Today, we announced that the ASPIRA trial is open for enrollment.

This is our Phase II double-blind, placebo-controlled study designed to evaluate the efficacy, safety and pharmacokinetics of 3 different dose levels of IPI-145 twice-daily plus methotrexate versus placebo plus methotrexate in more than 300 patients with moderate to severe rheumatoid arthritis. The primary efficacy endpoint of 12 weeks is the ACR20 response rate, which is defined as the proportion of people who at least -- who achieve at least 20% improvement in the American College of Rheumatology response criteria.

If the data are positive, this trial could enable us to move directly into Phase III development. We are also conducting a Phase IIa trial of IPI-145 in patients with mild allergic asthma.

We expect to provide an update of this trial in the second half of this year. In addition to our clinical efforts, we have an ongoing internal research program directed to identifying additional PI3 kinase inhibitors that will complement IPI-145.

We are continuing to advance our second PI3 kinase product candidate, IPI-443, through preclinical studies to enable Phase I development. IPI-443 has the potential to provide us with an important strategic flexibility and optionality as we pursue our dual-development pathways for our PI3 kinase franchise in both hematology and inflammation.

I will now provide an update on the 2 ongoing trials of our potent and selective Hsp90 inhibitor, retaspimycin hydrochloride. The first trial is a Phase II double-blind, randomized, placebo-controlled trial of docetaxel plus retaspimycin versus docetaxel plus placebo in patients with non-small cell lung cancer.

This trial of 226 second or third-line patients, who are heavy smokers and who are naïve to docetaxel treatment, has 2 co-primary end points: overall survival in the total population and overall survival in patients with squamous cell histology. A secondary endpoint is an undisclosed prespecified biomarker, which was discovered in our Phase Ib study.

As Adelene noted, we now anticipate reporting top line data from the study in the second half of 2013. The shift in timing is due to the rigorous conduct of the study.

This trial includes a review of all safety events by a data safety monitoring board, centrally reviewed histopathology and analysis of a validated biomarker assay in a CLIA-certified lab. The additional time is required to ensure that the requisite number of events is coupled with our correlative studies and our biomarker analysis.

Our goal is to determine whether there is a meaningful survival benefit in a population that warrants proceeding to a registration-enabling study. It's important to emphasize that since this trial is blinded, we do not know how the event rates may differ between the treatment arm and the placebo arm.

So there is no rationale for making inferences about the outcome of the trial based on the timeline. Our second trial in our Hsp90 program is an exploratory Phase Ib2 trial evaluating retaspimycin plus everolimus in non-small cell lung cancer patients whose tumors have activating KRAS mutations.

We are still in a dose exploration phase of this trial, and we anticipate providing an update from this study in the second half of this year as well. In summary, we continue to make strong progress advancing our pipeline and look forward to reporting data this year.

With that, let me turn the call over to Larry to review our financial results.

Thank you, Julian. Infinity is in a strong position, with a promising pipeline, approximately $300 million in cash investments and worldwide commercial rights to all of our programs.

Since we no longer have strategic relationship with Purdue, in April, we supported a secondary offering, which enabled them to fully exit their position of approximately 11.4 million shares. As a result of the secondary offering and the restructuring of our strategic relationship with them last year, Purdue no longer has any product rights but retains royalties on future sales of our PI3K product candidates ranging from 4% worldwide going down to 1% in the U.S.

only after we pay back through royalties the $260 million, which they contributed in support of Infinity's research and development projects during the time of our strategic relationship. I will now briefly review our financial results for the first quarter of 2013.

We did not record any revenue during the quarter. Total revenue was $25.2 million for the same period in 2012, which was composed of $24.2 million for reimbursed R&D services performed under our previous strategic alliance with Purdue/Mundipharma and $1 million from amortization of deferred revenue associated with the grants of rights and licenses under this alliance.

R&D expense for the quarter was $20.2 million compared to $28.6 million for the same period in 2012. The decrease in R&D expense in the quarter compared to the same period in 2012 was primarily related to the discontinuation of development of the company's Hedgehog pathway program.

G&A expense was $7.4 million for the quarter compared to $6.8 million for the same period in 2012. The increase in G&A expense in the quarter compared to the same period in 2012 was primarily due to higher stock-based compensation expense.

Net loss for the quarter was $27.3 million or basic and diluted loss per common share of $0.57 compared to $10.7 million or basic and diluted loss per common share of $0.40 for the same period in 2012. As of March 31, 2013, we had total cash, cash equivalents and available-for-sale securities of $303.1 million compared to $326.6 million at December 31, 2012.

In the absence of additional funding or business development activities and based on our current operating plans, we expect that our current cash investments will provide us with the cash runway into 2015. Importantly, we believe that we have the financial resources required to see all of the ongoing trials of our product candidates, including the trials announced today through their next key inflection points.

With that, I'll turn the call over to our operator for questions.

This is Whitney in for Cory. One, you mentioned in-licensing.

Can you talk about what kind of candidates you might be looking for there? Is that sort of with the eye of combo studies with 145?

And then secondly, for the Hsp90 program, in the ongoing trial, you said you want to see a survival benefit. What do you think you need to see there in order to take it forward?

So I'll start with the in-licensing since I've mentioned that and then turn it over to Julian for your second question. On in-licensing, we're really looking to something that will expand the portfolio.

We are not limiting it to the drugs that could be used in combination with anything in our existing pipeline. The criteria that we apply is something that we believe has a truly differentiated profile and the potential to serve a significant medical need.

And so we look primarily at small molecules, we look primarily in oncology, and we're looking at things that are from the stage from late preclinical development, at a stage where it can be readied for IND-enabling studies, up to something that already has some proof of concept in the clinic. But the most important thing for us is our belief that it really has the potential to make a difference for patients.

And I'll address the question on lung cancer. As I noted, the trial is powered for overall survival in the total population as well as survival in the squamous cell histology group.

These are the primary endpoints. However, we have a series of nested analysis, which include a pre-specified biomarker, which we are prospectively testing in this study as well.

And decisions going forward, that would warrant the initiation of registration trial will depend on the magnitude of benefit that we see and the confidence intervals with which we can comfortably convince ourselves that it's further warranted that we initiate a Phase III registration study. So we haven't commented on the specific statistics and the statistical analysis plan, but we do have a very rigorous process in place to make the best decision for patients going forward.

Okay, I was wondering what -- a lot of companies are reporting data at the Lugano meeting. It looks like you guys are reporting the T-cell lymphoma data there.

Is there anything you're originally planning to present at ASCO that you'll be holding for Lugano? I'm wondering if it's replicate [ph] at all or whether it will be the same information.

There's obviously a considerable overlap. I mean, the time difference between the 2 meetings, of course, is just a few weeks.

But the Lugano meeting will go into more detail, and I think we'll have perhaps a slightly updated version of our presentations even from ASCO, and we'll have that opportunity of a few weeks more observational period to make those adjustments.

Okay. And then on RA, I'm just wondering if you can give us anything about any sort of time line as to when you might -- I know it's hard, but any time line around when we can actually see the data that comes out of that study that you're just starting.

I'd like to do that. I think given that the trial is about 300 patients, we have modeled this out and expect data towards the end of 2014.

Just a first question on the RA trial. Can you show us the dosing of that trial, just how is that going to compare to the cancer setting?

Yes. Sure.

We -- I'd just remind everyone on the line that we did our Phase I in normal healthy subjects that covered doses up through 10 milligrams total daily dose, which included a cohort of 5 milligrams BID, as well as a 10 milligrams QD. So that would be the upper level of treatment exposure in the RA patients.

And we've selected doses lower than that to explore the full dose response range in RA patients. The doses are also consistent with a modeling effort that we took from our rodent RA models, and time dose exposure calculations were made to mimic what level of delta inhibition we would need to see in RA patients.

So consistent that with the rodent data, the preclinical data that we have as well.

All right. So just given your intention to move into Phase III trials if this trial is successful, thinking about it from a commercialization standpoint, we're talking about 2 very disparate indications market segments.

Should we be comfortable in potential pricing in these 2 different markets? And maybe not limiting the opportunity one for the other?

That's a great question, Joel (sic) [Ian], and it's one that we think a lot about -- it will depend very much on what the ultimate dose is in both the hem trials that we're conducting, as well as the RA trial. And of course, if there's an appropriate relationship between the dose and the responsiveness and the positioning from a market perspective, we might take 145 forward in both.

We also will be evaluating, as Julian mentioned, our second candidate, IPI-443, and we should have in the same timeframe some early data on that to see how 443 and 145 are similar or different, and that will give us, as Julian mentioned, the optionality from a strategic position to decide whether we direct those molecules towards different therapeutic areas. So we will be generating the data that will allow us to optimize this portfolio over the next 18 to 24 months.

Okay, and just one last question on the data, which was expected at the ASCO conference. Are you able to comment at all if we compare how the safety profile of your PI3 kinase compares to maybe some of the others in development at similar stages?

Are there -- is there enough data to maybe make a comment on whether there are any specific advantages or potential similarities in the adverse events profile?

Yes, let me first say it's very difficult to do cross-trial comparisons. Obviously, we don't -- we can never be sure that the entry criteria of patients is exactly the same.

It's a Phase I setting, and so it can be different from drug to drug. But that being said, we will be fully -- we will fully explain the safety data that we've observed both in terms of the different doses and the different patient populations.

This is John on behalf of Michael Yee. First, can you provide us with more color on the enrollment progress for the newly expanded cohorts such as when it's open?

And just your observation on which cohorts are potentially enrolling relatively quickly and which ones are taking longer than others so that we can get a better idea of how much data we can expect at ASCO. And I have one follow-up.

So the cohorts are enrolling relatively briskly now that all of the amendments are underway -- are through. And obviously, the more prevalent diseases are being enrolled more quickly.

That's just the function of the patients that show up in the clinic. But we are making concerted effort to see that all the cohorts are enrolled, and we'll provide again more detail at ASCO.

And I hope that answers your question.

Okay. Great.

And just as a follow-up. How much confidence do you have that IPI-145 will work in patients who failed either ibrutinib or GS-1101 such as is there anecdotal or in vitro PK evidence that IPI-145 might work in these patients?

At this point, it is looking very likely that these are the drugs that will have been on the market 1 to 2 years before your drug.

It's a very fair point and a burning question in our own minds. Let me say at the outset that the mechanisms are different.

Inhibiting BTK and inhibiting PI3K, there's certainly overlap in terms of B-cell receptor signaling. But they are independent mechanisms, and we are treating this molecule as an independent investigation.

And eventually, I'm sure we will have data when we'll be seeking data on ibrutinib failures or patients who have progressed on ibrutinib. And we hope that very much that the independence of the mechanism will offer patients yet more options, more treatment options in the event that patients have experienced ibrutinib and have progressed on ibrutinib.

In your ongoing trials, do you know if there are any patients who have failed either ibrutinib or GS-1101?

I can't comment on any specific patients. Again we'll present the patient backgrounds at ASCO, and I don't want to sort of forerun the opportunity at ASCO to present our data in totality.

This is Lisa in for Navdeep. And just 2 quick cash questions.

Any updates on how potential partnership discussions are going? If partnership is still in the picture, would it be realistic to obtain one before the extended cohort data?

And the second question is, can you walk us through your confidence in the NSCLC programs?

Sure, this is Larry. I'll take the first question and then turn it over to Julian for the latter.

In terms of partnering, our position is that we have all of the resources, financial and operational, in order to see all of the existing programs through the next key inflection points. And one of them just started today, which is the initiation of the powered [ph] Phase II study, which as Julian pointed out, would likely not read out until the end of 2014.

And so we have said that we're certainly having ongoing discussions. We're open to discussions.

We certainly want to have partners kick the tires. And if there's anywhere a partner who says that they would significantly accelerate, broaden, improve the campaign we have now in hem malignancies, as well as inflammation, we're certainly open to that discussion.

But we don't have any plans or guidance associated with concluding any kind of partnership in the timeframe we're speaking of.

With regard to the lung cancer trial, let me remind you that this trial was initiated based on signals that we saw from an open labeled Ib trial in relatively few number of patients. I think 26 patients were treated with a docetaxel retaspimycin combination.

And where we saw nice response rates, and particularly all the responses were heavy smokers, and we saw responses in patients with squamous cell histologies. So my confidence is based on that the trial was rigorously designed, rigorously blinded and rigorously conducted through the treatment period.

And I'm also very confident that it will be rigorously analyzed for its end point. As to the outcome, of course, being blinded to the treatment arms, I can't really handicap what outcomes will be.

But I feel confident that the way in which we've set up the trial and our belief in the biomarker, we have set up these series of analysis that should there be a clinical benefit in a subpopulation, we will find it. And based on the magnitude of benefit, it will guide us as to future studies, including registrational [ph] studies for this patient population, which is a very unmet need as you appreciate.

Okay. And any updates on those series of analyses?

Will you provide us with any updates?

I think we have never planned to do an interim analysis. We will do one analysis.

It will be a final analysis, and we'll be reporting top line data later this year. And we'll seek a medical meeting to appropriately outline all of the data.

It's a big undertaking, and I think we're geared up and ready to do so.

This is Jeremiah filling in for Jason. I know it's still early, but have you have been able to identify any lymphoma patient subpopulations that have a differentiated response with IPI-145 or other similar agents?

You're right, it's early, and we don't want to comment on, again, forerun the ASCO opportunity to talk about our data. I will remind you that what we had seen at the ASH -- as of the ASH data was activity in CLL, [indiscernible] Hodgkin's lymphoma, Hodgkin's lymphoma, mantle cell lymphoma and early activity in T-cell malignancies as well.

So we will be providing a full update at the ASCO presentations.

And as a follow-up question to a question that was asked earlier, but are you looking at potential novel-novel combinations with IPI-145? And if so, which drug classes look most interesting to you?

It's a great question. We are thinking about this all the time.

Certainly in the lab, we are exploring these from first principles and basic mechanistic combinations that make sense. And then there's the question of, can we contemplate the combination of experimental agents?

And of course, we're working on this.

Obviously, the least risky combination would be with approved drug with a well-known side effect profile and then going down to development stage with compounds that were target agents, non-cidal mechanisms. And obviously, the risk is would development stage that was cidal because of the potential safety profile.

And to underscore that, of course, we announced the combination of Rituxan and bendamustine and the triplet as well today.

So IPI-145 in hematologic malignancies, in these 5 expanded cohorts, when do you expect to complete the patient enrollment of 150 patients? Is that going to be done by ASH so we'll be able to see all the data?

Well, we strongly hope that as enrollment continues that we would be in a good position at ASH to really report more mature data. It's our intention to try to enroll all 5 cohorts, again approximately 30 patients per cohort, and explore additional malignancies, including the myeloproliferative neoplasms for which we don't yet have any data.

Okay. So with that progress, when do you expect to start a pivotal study or pivotal studies for this program?

So we have mentioned only that we will start 2 additional trials this year. You can infer from that, that obviously we're thinking along the lines of important trials that would lead us towards a registration path.

But I don't want to again preview any registrational [ph] path without having had conversations with regulatory authorities, both FDA and European authorities, as well as Japanese authorities. And we'll comment with greater precision when we initiate those studies.

That's fair. And then based on your comments, is it fair to assume that we are going to see 75-milligram BID dosing data at ASCO this year, some patients' data perhaps?

Well, we have enrolled a number of patients, as Adelene pointed out. And to the extent that they're evaluable and are cleaned in our database and we have a source verified the data, we will be presenting the most updated data set we have at ASCO.

So you can almost view as ASCO as kind of the midterm for our year, and ASH will, of course, be the final, where we have the most mature data for this -- for 2013.

Sure. One last question.

IPI-443, are you still on track to file IND in the second half of this year?

We've mentioned that we're conducting the preclinical activities for IPI-443. We have not guided as to when we're exactly filing for first-in-human studies.

Julian, with respect to the development of 443, what was engineered out of 145 or into 443 to differentiate it?

So in fact, IPI-443 has some very similar properties to 145. We did not find any deficiencies with 145 per se, so there was no need to sort of make an improved molecule.

443 is really designed to also be a delta/gamma inhibitor. It has some slight preferences for the gamma.

Maybe the window between delta and gamma are somewhat tighter at least in biochemical data. But it remains to be seen whether 443 is further differentiated pharmacologically from 145.

As I said, as Adelene pointed out actually, 443 was really designed to give us further strategic optionality in terms of picking indications so that we can both fully explore inflammation and hematology indications.

Okay. And just as a quick follow-up with respect to the 145 studies.

At what dose would you expect to have maximal inhibition of the target beyond which you'd be looking at some off-target effects?

Which target are you referring since it's targeting both delta and gamma? We are maximum inhibiting delta at doses of 25 milligrams and above to the tune of greater than the IC90.

And we are above the IC50 for gamma at 25 milligrams. And then we will present the PK/PD relationships for the 75-milligram dose at ASCO.

Okay. And just one last quick question.

What was the DLT preclinically with 145?

So we have 2 DLTs at 100-milligram. One was a Grade 3 Rash, and the other was a Grade 3 ALT elevation in the hematologic malignancy cohort.

Thank you, everyone, for joining us today. We're looking forward to presenting our updated data on IPI-145 at ASCO next month, and hope to see many of you there.

Thank you.