Hannah Deresiewicz - Stern Investor Relations Bassil Dahiyat - President and Chief Executive Officer John Kuch - Vice President of Finance.

Christopher Marai - Oppenheimer & Company Inc., David Nierengarten - Wedbush Securities. Arlinda Lee - MLV & Company. Jonathan Chen - Leerink Partners LLC..

Good afternoon and welcome to the Xencor First Quarter 2015 Conference Call. At this time, all participants are in a listen-only mode. Following the formal remarks, we'll open the call for questions. Please be advised this call is being recorded at the Company's request.

At this time, I would like to turn the call over to Hannah Deresiewicz of Stern Investor Relations. Please proceed..

Thank you, operator. Good afternoon. This is Hannah Deresiewicz with Stern Investor Relations and welcome to Xencor’s first quarter 2015 financial results conference call. This afternoon we issued a press release which outlines the topics that we plan to discuss today. The release is available at www.xencor.com. Today on our call, Bassil Dahiyat, Ph.D.

President and Chief Executive Officer will discuss the Company’s business and clinical highlights from last year. John Kuch, Vice President of Finance, will review the financial results. Then we will open up the call for your questions.

Before we begin, I would like to remind you that during the course of this conference call Xencor management may make forward-looking statements, including statements regarding the Company’s research and development, including clinical trial plans for XmAb 5871, XmAb 7195 and its bispecific products candidates, future financial and operating results, future market conditions, the plans and objectives of management for future operations and the Company’s future product offerings.

These forward-looking statements are not historical facts, but rather are based on Xencor’s current expectations and beliefs and are based on information currently available to us.

The outcome of the events described in these forward-looking statements is subject to known and unknown risks, uncertainties and other factors that could cause actual results to differ materially from the results anticipated by these forward-looking statements, including but not limited to, those factors contained in the Risk Factors sections of its most recently filed quarterly report on Form 10-Q.

With that let me pass the call over to Bassil..

Thanks Hannah and good afternoon everyone and thank you for joining us on today's call. We will be reviewing the first quarter as you can see we've already had a very busy start to the year. We kicked off 2015 with topline clinical data from our two lead internal programs XmAb 5871 and XmAb 7195 and I’ll review that in brief in a moment.

We also completed an equity offering in February, which raised net proceeds of over $115 million. This financing will greatly facilitate our strategy to broaden and independently advance our proprietary pipeline of novel antibodies including a range of bispecific antibodies using our newest XmAb FC domain.

Now major activities for the rest of the year will include initiating clinical testing of XmAb 5871 in a newly defined rare disorder IgG4-related disease. It’s an important opportunity for us because of the attractive clinical development and commercial landscapes for B-cell inhibitor such as 5871 in this newly defined disorder.

For XmAb 7195, we will continue to enroll patients in part two of the two part Phase Ia study and we look forward to reporting topline data from this part of the study which is on the high IgE subjects.

Also, we’ve advanced XmAb 14045, our bispecific oncology antibody for acute myeloid leukemia in preclinical development and expect to start clinical trials in 2016. We have additional bispecific oncology antibodies in preclinical development as well. Now I’ll review highlight from the data we announced for our clinical programs earlier this year.

Now to remind you, XmAb 5871, is our first-in-class B-cell inhibiting antibody containing our proprietary XmAb and immune inhibitor FC domain. It targets the receptor Fc-gamma R2b, via its FC domain in a target CD19 through its variable domain. There by engaging Fc-gamma R2b inhibitor function on B-cells.

In January, we reported topline results from a Phase Ib/2a study in rheumatoid arthritis showing promising auto immune disease modifying activities specifically a 33% or 5/15 rate of remission were low disease activity by the -28CRP criteria at two weeks post final dose. This was the protocol specified disease activity measure in time point.

We also saw a 20% ACR70 or reduction in the ACR symptom scale by 70% or greater and 40% ACR50 or production of symptoms by 50% or greater. Now the study was also designed to determine the safety and tolerability profile of XmAb 5871 and it show that it was generally well tolerated.

The most common 5871 treatment related adverse events observed were predominately milt to moderate gastrointestinal toxicities including nausea, vomiting and diarrhea that occurred during the first infusion of 5871. These GI adverse events, typical y did not reoccur on subsequent infusions and no infusions were discontinued to these.

Now treatment related serious adverse event s occurred in two patients that received 5871, these were an infusion related reaction and venous thrombosis. As well as, two patients have placebo had serious adverse events.

Now this data from this Phase Ib/2a trials, the first demonstration of our novel mechanism of action of FC-gamma R2b targeting that was data to show that we could treat an autoimmune disease by hitting this pathway. Not this data supports the potential of this non-depleting and highly potent way of inhibiting B-cells.

We plan to present the full data from this study in an upcoming medical conference this year and we also plan to start a clinical trial in IgG4 related disease this year. Now IgG4 related disease is a fibro-inflammatory autoimmune disorder that affects approximately 10,000 to 20,000 patients in the United States.

It’s newly defined and there are no currently approved therapies. Corticosteroids are currently the standard of care treatment. Now it appears that IgG4 positive plasmacytes, which are cells that progeny of B-cells play an important role in disease process. So B-cell inhibition has significant potential as a treatment modality.

The travel planning is an open-label pilot to assess disease control activity as measured by the IgG4-RD responder index, a response metric recently published by leading clinicians.

Now turning to our second clinical program, XmAb7195 this is our antibody that targets IgE with its variable domain and uses an identical XmAb immune inhibitor Fc domain as 5871.

In this context of IgE binding the Fc domain both inhibits B-cells, in this case just the IgE expressing B-cells, as well as rapidly targeting IgE for clearance from the circulation. In January, we reported topline interim data from part one of our two part ongoing Phase 1a study in healthy volunteers in allergic subjects.

Now the part one data showed that our drug is very potent with 90% of healthy volunteer subjects having a reduction of circulating free IgE to below the limited detection by the end of the 7195 infusion. Now that’s 95% of those subjects had a detectable free IgE response pre-dose.

Now that included those at the lowest doses evaluated of 0.3 milligrams per kilogram.

Now two subjects in this single ascending dose study with high pre-dos IgE levels that is above 300 units national units per mill which were treated XmAb 7195 now these two subjects one was at 0.7.5 milligram per kilogram dose level and one was at the 3 milligram per kilogram level, both had reduction of free IgE levels below the limited detection lasting for at least a week.

Now we did observe a dose limiting toxicity of transient asymptomatic thrombocytopenia or platelet reduction that was observed at the 3 milligram per kilogram dose level. We also observed moderate urticaria hives in some treated subjects with apparent correlation of dose with the frequency of occurrence of urticaria.

Now in all cases, regardless of dose the urticaria was signs and symptoms were mild, non-diffuse and easily treated with oral antihistamine.

We’re continuing to enroll patients in the high IgE subject portion of this trail or part two of the study, and we’re planning a multi-dose Phase 1b study as well as developing subcutaneous formulation of XmAb 7195.

We believe 7195 has the potential to provide a first-in-class mechanism for reducing IgE that will address the full spectrum of severe asthmatics, including the hardest to treat people with high IgE levels. Next I would like to turn to the newest aspect of Xencor’s portfolio , our XmAb bispecific technology.

Now our bispecific program use a novel Fc domain to serve as the scaffold for antibodies with two different antigen binding domains, creating a molecule that can bind two targets simultaneously hence the name bispecific.

By using a plug and play Fc domain is the basis for our bispecific structure, we can develop a very flexible approach that lets us create candidates by combining any two binding domains, while potentially maintaining the beneficial properties of full length antibodies, such as favorable in-vivo half-life and simplified manufacturing.

We also hope that this modularity lets us to engineer potency levels to improve the tolerability of the cancer immunotherapy which are currently quite toxic. XmAb 14045 is our lead by specific program and its target CD3 on T-cells to direct cytotoxic T-cells to the other targeted antigen which is CD123 on acute myeloid leukemia cells.

It showed very effective and potent depletion of target cells in primate studies from a well tolerated single IV dose. In addition manufacturing scale up is under way for this molecule using standard antibody production methods. We hope to offer product profile of simple and efficient manufacture, convenient well tolerate dosing and high potency.

And we expect to initiate clinical trials for XmAb 14045 in 2016 and in addition we planned to advance to the clinic one more oncology bispecific candidate in 2016. Now in conclusion regarding the team here at the Xencor, in March of this year, we announced the appointment of Bruce Montgomery M.D to our board of directors.

Currently Bruce serves as Chief Executive Officer of Cardays pharma and he has more than 25 years of drug development operations and financing experience in the Life Sciences industry. With strong medical reputation coupled with his expertise in drug development is a great addition to the board.

With that I’ll now turn the call over to John to review our financials..

Thank you, Bassil. In this afternoons press release we reported cash equivalence and marketable securities totaling $166.9 million as of March 31, 2015 compared to $54.7 million on December 31, 2014.

The net increase in total cash and marketable securities in the first quarter 2015 compared to our year-end balance at December 31, 2014 is primarily due to the completion of our follow-on financing the first quarter of 2015 in which we raised net proceeds of approximately $115 million.

Revenues for the first quarter 2015 were $1.5 million compared to $2.2 million in the same period of 2014.

Revenues earned in the first quarter of 2015 were earned primarily from our Novo Nordisk and Alexion collaborations compared to revenue earned in the first quarter 2014, which was earned primarily from our Amgen collaboration which was terminated in the fourth quarter of 2014.

Research and development expenditures for the first quarter of 2015 were $5.2 million compared to $4.2 million for the same period in 2014.

Increased research and development spending in the first quarter of 2015 over the same period of 2014 reflects increased spending on our XmAb bispecific platform and drug candidates including development cost for first bispecific clinical candidate XmAb 14045.

General and administration expenses in the first quarter of 2015 were $2.8 million compared to $1.7 million for the same period in 2014, increased spending in the general, and administration area was increased staffing of legal and accounting personnel and other cost related to being a public reporting company.

Non-cash share based compensation expenses for the first quarter ended March 31, 2015 was $1.1 million compared to $0.3 million for the first quarter ended March 31, 2014.

The net loss for the first quarter 2015 was $6.4 million or $0.19 on a fully diluted per share basis compared to a net loss of $3.7 million or $0.12 on fully diluted per share basis for the same period in 2014.

The net loss for the quarter ended March 31, 2015 was $2.7 million greater than a net loss for the period ended March 31, 2014 as the result of lower revenue of $0.7 million and increased expenses of $2 million.

Weighted average shares outstanding used to compute earnings per share was 34,297,782 shares for the quarter ended, March 31, 2015 compared to 31,360,879 shares for the period ended March 31, 2014. The increased shares outstanding for the period ended March 31, 2015 reflect additional shares issued in our financing.

Based on current operating plans, we expect to have sufficient cash to fund research and development programs in operations in 2019. With that we will now like to open up the call for your questions. Operator..

[Operator Instructions] Our first question comes from the line of Chris Marai with Oppenheimer. Your line is now open. Your question please..

Hi good afternoon guys and thanks for taking the questions.

You know so first I was going to ask regarding your cash guidance and interestingly your cash will be sufficient through 2019, does that encompass any consideration for potential partnerships going forward and then secondly I wanted to touch basically with you guys on the part two of 7195 Phase 1 trial and I know that’s double-blinded placebo controlled, but is there any indication that you have at the current time that you’re seeing severe side effects such as in the high IgE subjects.

Thanks..

Let me answer the first question, Chris. Thanks for the question. Regarding the cash guidance, we do not project any milestones or additional revenue from existing collaborations in the model; I’m very conservative because we don’t have control over those things. So that’s basically upside for purposes of the runway.

As far as second question, I’ll let Bassil, address that..

Right. So the study is double-blinded ongoing and still recruiting, so we really can’t speak to what kind of results we’re seeing and in fact until we see them ourselves..

Okay.

But there is no indication of any severe side effects, anything like that, would you have an indication of that at any time point, if there to occur?.

We haven’t had any announcable events, I can say that and I know certain kinds of adverse events are announcable, so we haven’t any of those..

Great. Okay. Well, thanks guys. I appreciate taking the question..

Thanks, Chris..

Thank you. Our next question comes from the line of David Nierengarten with Wedbush Securities. Your line is now open, your question please..

Thanks. Hi, Bassil.

My question is regarding the bispecific trial program, you mentioned AML and there are other high expressing cancers that IR3 are expressed at high levels I mean did you think about or are you planning to include or screen for those patients with those malignancies when you open that study?.

Yes. So final study design in enrolment criteria have not been decided, I think, we certainly are aware of some other tumor types, some of which are rare and in some instances you have sub types of solid tumors even. We’re considering how to design the study to most rapidly get through dose escalation and get safe and effective doses, if we have such.

But it’s hard to say what we’re going to do now in that first study. We certainly very much want to explore and develop anywhere we think there might be a good fit including in other indications outside of AML. What happens in that study is just too hard to say right now..

So you focus on AML and not necessarily stratify the tumor opening days of - would be of Basel study?.

That’s the thought right now..

Okay..

If we do expand that to include other kind of tumor types in the first announced study, we will certainly let people know. Because there could be some very exciting opportunities as you said another place is where author receptor is over expressed in a tumor..

And then, I know, it’s a probably way too ahead of the game to ask this question but in terms of thinking about the biology again the tumor, would you ever consider thinking about a program or you have a debulking regimen for the AML patients and then followed with your bispecific to essentially mop up the leukemic stem cells until they tend to express the CD123 antigen.

Have you thought about that, or is that just not too far ahead..

It’s a little far ahead; I think you’ve got such a broad and deep set of unmet needs in AML. You’ve got certainly a much higher relapse rate than you’d wanted. It happens much faster than you’d want. Consolidation therapy is not great, right either. You’ve got a situation where people can be in complete response and they’re relapsing.

So there is an MRD contacts. All these contacts have to be a potential place for an immunotherapy like 14045, I think; again that first trial and I don’t want to comment too much until we have things nailed down in terms of this event.

The first trial is, get safe and effective doses as quickly as you can in a safest way for patients and then go into the various settings. But I think all the settings have a profound unmet need, there is no shortage of opportunity in AML..

Yes, just speculating, so thanks for indulging me on that one. Have a good one..

Thank you. Our next question comes from the line of Arlinda Lee with MLV & Company. Your line is now open, your question please..

Hi guys thanks for taking my questions.

Two of them, one can you provide us an update on maybe some of the discussions you’ve been having with regulatory agencies and key opinion leaders on what your IgG4 related pilot study might look like and what kinds of information you might hope to get out of that and then secondly on the bispecific program the second compound that you like to advance into the clinic in 2016, is that do you think for maybe one of the CD20s or CD38s that you’ve already presented preclinical data for is it something completely different.

Thank you..

Thanks. So for the IgG4 related disease trial we plan on starting this year, we have been working very hard talking care and trying to understand how we’re going to fit into the regulatory landscape.

I think that it’s a key objectives would have want to determine is in a pilot setting do we can we see clear disease modifying activity for the agents and critical in that is we selected it and are committed to the IgG4-RD responder index which the first version of it was published just little while ago by Dr. John Stone.

He was lead investigator at Massachusetts General and we plan on using that index as we run this trial, they really try to see if we can one measure activity in the index and two start to build the database around that metric to build its credibility and validity. Because that is going to be critical to go back to it later.

So we are initiating a large validation study, so essentially a large paper case study with large number of physicians to build the validation dataset around the index and that would complement our clinical data.

And so with the small pilot trial in open label trial there is not too much more to say about how we’re going to run it until we do start it but again it’s looking for activity, we have good models from the rituxan study that was done a couple of years ago by Dr. Stone.

Now on your second question, what was the second specific program we hope to enter into the clinic in 2016 be and we haven’t announced because we’re still essentially deciding then and the way we are going about doing that is we have multiple agents or CD38, 13551 program and the CD20, CD13676 are both advancing in preclinical development and process development and we have other molecules of undisclosed target antigens in CD3 also advancing.

The modularity of the platform really has been playing out.

It is quite straightforward for us to do the early development here, while we really decide what is the best one for Xencor and the best package of things for an internally driven candidates and that sort is juxtapose next to which of our molecules are best suited for potential future partnering, perhaps at the preclinical stage.

So we have this opportunity to try to do this optimization exercise without losing time because we can advance multiple of these in these early development stages before we hit the real connect steps GMP Production and et cetera. So we will announce that later this year but we are just not announcing it right now..

Okay..

[Operator Instructions] Our next question comes from the line of Jonathan Chen with Leerink Partners. Your line is now open. Your question please..

Hi it’s Jonathan Chen stepping in for Michael Schmidt. Thanks for taking my question.

I’m just curious for 7195, how many high IgE patients worth this data, can we expect to see later this year?.

I’m sorry how many IgE patients with what could we expected this later this year?.

Worth of data..

Worth of data, sorry. Well we are enrolling right now certainly its season, allergy season which always helps bring people out of the woodwork and we are looking to announce, we’ve run the study in cohort of eight subjects in part one or part two similar to that. So we would expect in the range of up to the full three cohorts of 24 subjects.

So it could be up that high, we might be stop before then. It just depends on timing and logistics..

Okay. Thanks..

Thank you. I’m showing no further questions in the queue at this time. I would like to hand the call over to Ms. Bassil Dahiyat for any concluding remarks..

Thanks very much. Now we look forward to continuing work on these programs, 5871, 7195 in our bispecifics as we progress through the year and finally, I would like to close by announcing that we’re planning to hold an R&D Day in New York City on June 26 to provide further information on our pipeline and platform.

And we will be announcing the details of that event shortly. Thanks again for your time and look forward to speaking again. Bye-bye..

Ladies and gentlemen, thank you very much for your participation. This does conclude the program. You may now disconnect..