Good morning, and welcome to Mersana Therapeutics' Third Quarter 2020 Conference Call. Currently, all participants are in a listen-only mode. There will be a question-and-answer session at the end of this call. I would now like to turn the call over to Sarah Carmody, Executive Director, Investor Relations and Corporate Communications. Please proceed..

Good morning, and welcome to Mersana's third quarter 2020 conference call. We issued a press release earlier this morning reviewing our third quarter 2020 financial results and business updates, which will be covered on this call. A replay of today's call will be available on the Investors & Media section of our website.

After our prepared remarks, we will open the call for Q&A. Before we begin, I'd like to mention that our call will contain forward-looking statements within the meaning of federal securities laws. These are not statements of historical facts and are based on management's beliefs and assumptions and on information currently available.

They are subject to risks and uncertainties that could cause the actual results and the implementation of the company's plans to vary materially, including the risks that our early encouraging preclinical results for XMT-1536 and XMT-1592, are not necessarily predictive of the results of our ongoing or future discovery programs or clinical studies that the development and identification of the company's product candidates and new platforms will take longer and/or cost more than planned, and that our clinical trials will not be completed on schedule, if at all.

These risks are discussed in the company's SEC filings, including, without limitation, the company's annual report on Form 10-K filed on February 28, 2020, the company's quarterly report on Form 10-Q for the quarterly period ended March 31, 2020, filed on May 8, 2020 and subsequent filings.

In addition, while we expect that the COVID-19 pandemic might adversely affect the company's preclinical and clinical development efforts, business operations and financial results, the extent of the impact on the company's operations and the value of the market for the company's common stock will depend on future developments that are highly uncertain and cannot be predicted with confidence at this time, such as the ultimate duration of the pandemic, travel restrictions, quarantines, physical distancing and business closure requirements in the U.S.

and in other countries and the effectiveness of actions taken globally to contain and treat the disease. Except as required by law, the company assumes no obligation to update these forward-looking statements publicly, even if new information becomes available in the future.

And with that, I'll turn the call over to Anna Protopapas, Mersana's President and Chief Executive Officer..

Thank you, Sarah. Good morning, everyone, and welcome to the third quarter of 2020 corporate and financial update call. Joining me today with prepared remarks are Brian DeSchuytner, our Senior VP of Finance and Product Strategy; and Tim Lowinger, our Chief Science and Technology Officer.

I'm also joined by the rest of the executive team, who will be available for your questions, including the newest member, Chuck Miller, Senior Vice President of Regulatory Affairs.

Chuck joined us in late August and brings with him over 25 years of regulatory affairs, program leadership and product development experience, expertise that is critical at this point in Mersana’s evolution.

Most recently, Chuck was Vice President of Regulatory Strategy and Labeling at TESARO, before its acquisition by GSK and was instrumental in the approval of ZEJULA in multiple indications and geographies. Welcome Chuck, we are very excited to have you on board. I will now turn to the business update.

Since the beginning of the year, we have continued to execute against our goals and milestones and have made significant progress in advancing our clinical and early stage pipeline of innovative ADC product candidates. I'll begin with 1536.

In September, we provided an incremental data update on the ovarian cancer cohort of our expansion portion of the XMT-1536 Phase 1 study, as part of the virtual ESMO meeting. This data were encouraging because they demonstrated a safety, tolerability and activity profile consistent with a compelling expansion data previously reported at ASCO.

In terms of the safety data presented at ESMO, treatment-related adverse events were primarily Grade 1 and Grade 2 fatigue, nausea, decreased appetite, vomiting, and the transient AST elevations, and were consistent with the expansion data previously reported at ASCO.

No new safety signals were observed, importantly, there were no reported cases of the severe neutropenia, peripheral neuropathy or ocular toxicities often seen with other ADC platforms.

In terms of activity data presented at ESMO, overall response rate and disease control rates remain consistent with the robust activity seen in the data previously reported at ASCO, specifically of the 29 patients that were evaluable full response, two achieved confirmed complete responses and eight achieved confirmed partial responses for an objective response rate of 34%.

Additionally, 45 patients achieved stable disease or an overall disease control rate of 79%, responses appear to deepen over time. 50% of patients remained on study as of the data cut. Note that the population studied in the expansion cohort represents late-stage patients with a very high unmet need.

30% of patients in our expansion cohort were platinum-refractory, meaning disease progression within less than three months of their last dose of platinum. It is well-established that platinum-refractory patients do even more poorly than platinum-resistant patients.

70% of the patients had prior treatment with bevacizumab and 53% had prior treatment with PARP inhibitors. In fact, both patients with confirmed complete responses had prior treatment with both bevacizumab and PARP inhibitors.

The only remaining treatment options for these patients are currently single-agent chemotherapy, such as pegylated doxorubicin or topotecan.

Often cited contemporary studies, including the now failed FORWARD1, JAVELIN 200 and CORAIL studies demonstrate the performance of single-agent chemotherapy is at best at 12% objective response rate with platinum-resistant patients that had had up to three lines of therapy.

The population in our expansion cohort is a more heavily pretreated population with an even higher unmet medical need and significantly more prior bevacizumab or PARP pre-treatment. Specifically, 40% of the patients in the expansion cohort had four or more lines of therapy.

The prognosis for patients who have more than three lines of therapy is not well characterized, but all the longitudinal studies have shown repeatedly that outcomes deteriorate with increased lines of therapy. These patients represent the most challenging group that physicians treat today. We're very encouraged with the emerging profile of XMT-1536.

We have now significantly exceeded the response rate of the standard-of-care in both the dose escalation and expansion portions of the study, even though we're enrolling more heavily pretreated and later-stage patients with more prior exposure to bevacizumab and PARP inhibitors.

We also observed significantly durable reductions in tumors, including a late-stage patient who experienced a complete response and had been on study for 42 weeks as of the date of the release and other complete response patients who came off study at week 19 was still in complete response when we scan at week 28, without additional therapy.

And the third patient with multiple five centimeter lesion achieved complete elimination of those tumors. Although, early and still a small number of patients were encouraged with the duration of response, particularly in patients with higher NaPi2b expression and those who achieve deep responses.

In the third quarter, the FDA granted Fast Track Designation for XMT-1536 for this patient population, further underscoring, the high unmet medical need for a treatment for patients with platinum-resistant ovarian cancer and the potential of the agent to have a clinically meaningful impact on patients.

Turning now to the Phase 1 study and our next steps, we have exceeded our goal of enrolling 40 to 45 patients in the ovarian cancer expansion portion of the study. We've continued investigator enthusiasm for XMT-1536. Recall that the ESMO data included 47 ovarian cancer patients at the data cutoff date of August 18, 2020.

Since then, we have continued to enroll patients and accumulate further safety, tolerability, efficacy, duration of biomarker data. We expect to continue to enroll ovarian cancer patients in this expansion portion of the study through the remainder of the year and until the initiation of the anticipated registration-enabling study.

We're also preparing to meet with the FDA in the near future to gain their feedback on the path to registration for XMT-1536.

We believe based on high unmet medical need, discussions with key investigators and regulatory experts and precedent in ovarian cancer that there is a potential for a path to accelerated approval in platinum-resistant ovarian cancer.

A differentiated profile without severe neutropenia, peripheral neuropathy, or ocular toxicities; they offer the potential for combinations with other agents such as chemotherapy or immuno-oncology.

We are also developing a longer term development plan in lifecycle management plan for XMT-1536, including options for combination studies to evaluate the potential of moving XMT-1536 into earlier lines within the ovarian cancer treatment landscape.

Given the significant ongoing activities associated with the advancement of XMT-1536 in ovarian cancer. We plan to hold it Analyst and Investor Day around the end of the year, to provide an update, the Analyst Day will include updates on three components.

First, we will provide an additional view of the expansion cohort data that will include more patients and longer follow-up.

Our preliminary guidance on the scope of this additional data update is that it will include approximately a total of 40 to 45 RECIST evaluable patients, a total of approximately 65 to 70 patients, and approximately three months of follow-up to the August ESMO data cut.

Given that the expansion study will still be open in enrolling at the time of this update, there will be additional patients on study that are not yet with this value port. Second, we would define our plans for a registration enabling study informed by FDA feedback.

And certainly we’ve outlined our objectives with longer-term life cycle management studies that will evaluate the potential of this agent in the platinum-sensitive setting, as we advance our vision of establishing XMT-1536 as a transformative agent in the treatment of ovarian cancer.

The logistics of this event will be announced once our plans are finalized. I'll now provide an update on the lung adenocarcinoma cohort in the expansion portion of the Phase 1 XMT-1536 study. Since our last call, we have initiated new international sites and have began to see some momentum in patient enrollment.

We expect recruitment will continue through the rest of the year and into 2021. We will discuss our plans to disclose data from the lung expansion cohort, when we layout our goals and milestones for 2021, in early January. I'll now turn to XMT-1592, a Dolasynthen ADC targeting NaPi2b.

The dose escalation portion of the Phase 1 study is moving forward as planned. We will continue to work to achieve rapid dose escalation throughout the remainder of the year and we'll discuss our plans to disclose dose escalation data, when we layout our goals and milestones for 2021 in early January.

As we have outlined in the past, the objective is to compare the XMT-1536 lung adenocarcinoma expansion data with the XMT-1592 data to make decisions as to which molecule we will take forward.

Lastly, we plan to disclose data supported our first thing, after this ADC candidate from an immunosynthen platform in November and our B7-H4 ADC development candidates around the end of the year. With that, I will now turn the call over to Tim, who will provide more details on our plant disclosures relating to these two exciting pipeline molecules..

Thank you, Anna and good morning, everyone. As Anna said, we've continued to make significant progress in advancing our B7-H4 DolaLock and immunosynthen STING-agonist ADC late-stage discovery programs. I'll begin with our upcoming preclinical disclosures for our immunosynthen ADC platform. This morning, our SITC abstract was posted to the SITC website.

Beginning on November 11 at 9:00 AM, Eastern time, this e-poster will be available on-demand in the SITC virtual poster hall. The SITC’s poster describes novel research undertaken by Mersana scientists, elucidating the mechanism of inmate immune activation to activation of the STING pathway with a tumor targeted STING ADC.

The research demonstrates that induction of the STING pathway is facilitated by a one, two punch from both the uptake of the immunosynthen ADC in tumor resident immune cells to Fc-gamma receptor and tumor antigen mediated ADC internalization, and that STING activation occurs in both of these cell types.

Based on in vitro experiments in monoculture, it has been widely believed that the STING pathway is silenced in cancer cells. However, the data we present in the poster overturns this widely held misconception.

Our STING ADC, activates the STING pathway in both tumor resident immune cells and in the tumor cells, providing a one-two punch to the tumor resulting in robust efficacy and immune memory and differentiating this approach from other innate immune activators.

In addition, we observed robust activity across multiple targets and models, demonstrating the breadth of applicability of this platform and its potential for building a pipeline of immunosynthen ADCs.

In addition to the SITC poster, we issued a press release this morning, announcing that we will be hosting a webinar on Monday, November 16 at 8:00 AM Eastern time, where we plan to provide a comprehensive overview of the immunosynthen STING-agonist ADC platform.

The event will cover a summary of the science behind the SITC poster, the rationale for the development of STING-agonist ADCs, the development and optimization of the immunosynthen platform, the potential STING-agonist ADCs across multiple targets and indications, preclinical data supporting the company's immunosynthen ADC pipeline, as well as the IND timeline for our first development candidates on this platform.

I'll now discuss the next steps for B7-H4. Our next first-in-class DolaLock ADC development candidate. We are excited about B7-H4 as an ADC target because it has a unique expression profile. It is expressed on tumor cells, but is also expressed on immunosuppressive tumor-associated macrophages.

This represents an ideal expression profile for DolaLock ADC.

Targeting B7-H4 in tumor cells provides a direct cytotoxic effect, while targeting B7-H4 on tumor associated macrophages can lead to catabolism of the ADC and releases the B7-H4 payload in the tumor environment where it can further contribute to bystander killing and immunogenic cell death, resulting in activation of dendritic cells and prompting a potential immune response.

What we call a perfect storm. We have generated some very compelling efficacy and non-human primate tolerability data with both our Dolaflexin and Dolasynthen ADC platforms to support the selection and further development of a first-in-class B7-H4 DolaLock ADC.

We plan to present some of these data and disclose our B7-H4 development candidates at the analyst and investor day event, we are planning to hold around year end. We look forward to sharing more information on this exciting program at that time. And with that, I'll now turn the call over to Brian for an overview of our financial results..

Thank you, Tim. Good morning everyone and thank you for joining us. On a personal note, I'm really happy to be working with Chuck again, so welcome to the team. I'll now review some of the key financial highlights from our third quarter 2020 results, and I'll start with our cash position.

We ended the third quarter of 2020 with approximately $271 million in cash and cash equivalent, having disposed of marketable securities held at the start of Q3 at maturity without new purchases due to the low interest rate environment. This compares to approximately $100 million in cash, cash equivalents and marketable securities at the end of 2019.

Net cash used in operating activities in the third quarter was $20.2 million. In addition to our current cash position, we have the option to draw funds through the amended existing debt financing agreement with Silicon Valley Bank, refinanced in August of this year. Today, we are reiterating our prior cash runway guidance.

We expect that our current cash, and equivalents, including the proceeds from the public stock offering in Q2 will enable us to fund our current operating plan commitments for more than two years. And now some of the key highlights from our third quarter 2020 financial results.

Collaboration revenue in the third quarter of 2020 was immaterial, compared to the $0.8 million for the same period in 2019. The decrease in collaboration revenue was primarily a result of the completion of research services associated with a target included in the Merck KGaA agreement in the third quarter of 2019.

Research and development expenses for the third quarter of 2020 were approximately $16.5 million, compared to $13.7 million for the same period in 2019. The difference was primarily due to an increase in manufacturing activities for XMT-1536 and our discovery stage programs.

An increase in XMT-1536 and XMT-1592 clinical expenses, increased headcount and increase in valuation of stock-based awards, increase in consulting and professional fees and advancement of companion diagnostics development efforts for the NaPi2b biomarker.

All of these were partially offset by a decrease in preclinical development and manufacturing expenses for XMT-1592, and the discontinuation of XMT-1522.

General and administrative expenses for third quarter of 2020 were approximately $5.9 million compared to $4.4 million in the same period in 2019, the increase was primarily attributable to an increase in consulting and professional fees, an increase in evaluation of stock-based awards and an increase in facility-related costs as a result of the extension of our leafs in March, 2020.

Net loss for the third quarter of 2020 was $22.5 million or $0.33 per share, compared to a net loss of $16.8 million or $0.35 per share for the same period in 2019. Weighted average common shares outstanding for the quarters ended September 30, 2020 and September 30, 2019 were approximately $68 million and $48 million respectively.

I'll now turn the call back to Anna..

Thank you, Brian. I'm very pleased with our significant accomplishments this year. And we remain on track to deliver on the remainder of our goals and milestones we set out at the beginning of the year.

To recap this remaining goals and milestones, we're planning for a virtual analyst and investor day around year end, where we will provide an update on XMT-1536, including more data from the ovarian cancer cohort of the expansion portion of our Phase 1 study for 1536.

We're also planning to disclose data supporting our first-in-class B7-H4 development candidates and the data to support expanding this program into the clinic at this event.

Separately, we will host a webinar focused on our immunosynthen STING-agonist ADC platform on November 16, where we will provide further preclinical data to support the significant potential of this platform. 2020 has been a transformative year for Mersana to date.

The Mersana team has delivered against goals, despite the challenges associated with COVID-19. I want to thank each one of our employees for their hard work and their unwavering dedication to advancing science and helping patients.

We look forward to sharing the additional progress we’ve made in advancing our clinical and late stage discovery programs in towards reaching our overarching goal of developing life-changing ADCs that significantly improve outcomes for people living with cancer. With that, I will turn the call over to the operator for Q&A..

Thank you. [Operator Instructions] Our first question comes from Jonathan Chang with SVB Leerink. Your line is open.

Good morning, and thanks for taking my questions.

First question, can you talk about your thoughts and strategy for 1536 in earlier lines of ovarian cancer and in combination settings?.

Jonathan, thank you for that question. We are working on that plan, and as we've said in our prepared remarks, we will be sharing that plan with investors at the analyst and investor meeting around year end.

But you can imagine that given the tolerability and safety profile of 1536, there are some very interesting opportunities to combine with some of the earlier lines of some of the other agents without seeing dose limiting overlapping toxicities.

So we are working on those opportunities and we'll be able to describe them in more detail once we get to our next disclosure..

Got it. Thank you.

And second question, can you talk about how you're thinking about the lung cancer opportunity for 1536 and 1592? What are the reasons for confidence that 1536 and/or 1592 could work in lung cancer?.

So as we've published before we have done extensive work to characterize the expression of the antigen in lung adenocarcinoma. We know that NaPi2b is expressed in those patients, it's expressed fairly broadly. And we also know that lung cancer is responsive to the [indiscernible] payload, which is the class of our own proprietary DolaLock payload.

Furthermore, we've disclosed some early data and we saw one response in a patient in the 43 milligram per meter squared dose of the doses escalation, and we see multiple curable stable disease.

We're continuing to recruit, as we’ve said, we need to get more patient experience here and we're continuing to recruit, we're encouraged with the pickup we’ve seen with patient recruitment in the last couple of months. And we look forward to disclosing data in 2021, both on 1536 as well as better understanding the differentiated profile of 1592.

And we will be able to compare the data and make the best decision – data driven decision as to the next steps in developing NaPi2b agency in adenocarcinoma patients..

Got it. Thank you.

And can you just remind us the key differentiating points between 1592 and 1536? And how that could potentially give you guys a leg up in lung cancer?.

So in preclinical models, we have observed that 1592 has a four-fold higher efficacy and at least this good tolerability than 1536, which is pretty exciting given that we've seen some early activity in 1536. I think we attribute that to increased tumor penetration which we have demonstrated preclinically.

So we're moving ahead fairly efficiently in the doses escalation, we dosed our first patient with 1592 in May and we're proceeding with a dosage escalation. So in 2021, we'll really look forward to looking at the dose escalation data, understanding how that preclinical differentiation translate into patients.

And if we truly translate into patients, which could have a very exciting agent, because it would be improved over an already active molecule..

Got it. Thank you very much for taking my questions..

Thank you. Our next question comes from Boris Peaker with Cowen. Your line is open..

Great. Good morning and thanks for taking my questions. First, I just want to kind of maybe set expectations on 1536 and durability of response.

What do you think is the minimum meaningful durability of response here?.

So Boris, we have asked this question in the past. I think the data will tell us what the overall durability of response will be. As of ESMO, I think we were still gathering data and share that data at the ESMO poster.

Your question is, how would the FDA look at the overall profile of the drug? I would maybe ask Chuck, who has a lot of experience with these type of FDA interactions and – particularly with ovarian cancer drugs to maybe share his comments with us..

Sure, Anna. Thank you. So I could say that based on the discussions that we've had with investigators over the years and my own personal experience in the indication, it's clear to me the FDA looks at the totality of data and balances the risk benefit.

I can say that having worked in ovarian cancer and in single-arm study, I joined, Mersana excited about the prospects of 1536, and I remain excited about those prospects..

Okay.

I guess, second question is how important is the delta in terms of response rate between the NaPi2b high and NaPi2b low? Even if you move the actual cutoff threshold, like how critical should the delta be?.

I'm not sure I understand the question..

No. I'm saying if we look at the response rate in the NaPi2b low patients and in NaPi2b high patients, there is going to be some kind of a delta, I believe it was about 6% or so in the prior update that you had.

I'm curious how important is it to have a high difference in response rates between NaPi2b low and NaPi2b high patients?.

So we are encouraged with both the overall response – the response rate in the overall population. But we're also looking at the response rate in the subgroup. Our objective is really to look at the totality of the data and really understand as best as we can how selection of patients impacts patient outcome.

So beyond the overall response rate, we're seeing some trends where the biomarker has impact on other important patient outcomes. And our objective at the low – by the time we launched the registration-enabling studies, really to understand and define how we would use patient selection to improve patient outcomes.

So there is a possibility we would look at the total population and use the diagnostic as a complimentary diagnostics. There is also the possibility that we will select patients for the registration trial and use the diagnostic as a companion diagnostic.

I think we're look – we need to continue to look at the totality of the data and make the best decision – data driven decision and how we're going to use the diagnostic.

We’re encouraged that the overall population has a pretty robust level of activity, but we're also encouraged that there is a potential strategy here to improve patient outcomes further by selecting patients.

And this we've always said the totality, we were [Technical Difficulty] data sets, which will be quite robust as you can appreciate, given that by the end of this year, we could have as many as 60 patients and as many as 40 to 45 evaluable patients..

Great, thank you very much for taking my questions..

Thank you. Our next question comes from Tom Shrader with BTIG. Your line is open..

Good morning, congratulations on all the progress. I wanted to ask kind of an open-ended question on the STING program that a lot of these, that people took into the clinic and then were somewhat disappointing.

Are there newer or preclinical models where you think you can differentiate yourself from some of the other approaches? Can you get excited that yours is better pre-clinically or will the real – will we really have to wait for clinical data? Just curious your thoughts on how much we could be convinced from a preclinical model..

So Tom, thank you for the question. We're extremely excited with the data we have with Immunosynthen platform. And I hope you're going to join us at the webinar, now we're having, but maybe Tim can comment on how – why we're so excited about the data..

Sure. Good morning, Tom. As we mentioned, we're disclosing data at SITC, that we think is very exciting and does differentiate our STING ADCs from other approaches for innate immune activation.

So I don't want to steal our thunder from SITC, but I would direct you to that poster and also to our webinar next week, if you can join us we'll get into those details.

I will say that pre-clinically, we're very excited about the data that we've already disclosed, including at AACR earlier this year that shows very robust activity after a single dose at quite relatively low levels, including innate immune memory, such that rechallenge the tumors do not regrow.

And we've seen that not only against one target, but we've seen that again, multiple targets. So pre-clinically, I think our data holds up very well and we very much look forward to sharing more details at SITC and at the webinar next week..

All right. Fair enough. Thank you..

Thank you. Our next question comes from Jessica Fye with J.P. Morgan. Your line is open..

Hi, this is Daniel for Jessica Fye. Thanks for taking our question. First one from me would be the press release, as you’ve outlined in the prepared remarks that you've continued to dose escalate 1592, and that you're proceeding to higher doses.

What is going to change over the next two months that prevents you from outlining data disclosure plans today or out of your analysis today?.

Just to make sure I understand the question, you're asking why we're not outlining plans to disclose data now when we would be waiting to around year-end, is that the question?.

Now or year end instead of early January, 2021 for 1592, yes?.

Well, as you know, we use – we and many other biotech companies outline our goals for the year around your conference at JP Morgan, which this year will be virtual. I understand. So it's typical for companies to outline their goals at that time. We’re in dose escalation, every dose cohort gives us more information about the profile of the drug.

And it gives us more information as to how close we might be to MTD. So another two months, two and a half months will give us that much more information and we'll be able to get be more informed as we layout our disclosure plans for 2021..

Got it. Okay. And then maybe second question. It sounds like the European sites have led to a pickup of enrollment for 1536 in lung cancer. Have the U.S.

sites picked up in terms of enrollment as well, or is there something about the treatment paradigms in terms of what the physicians want to turn into later lung line cancer in Europe versus the U.S.?.

So let me clarify the sites, international sites are in Australia and Canada. These were sites that were planned to go online, back in March and were delayed because of COVID-19.

I think we've seen a pickup across the board in all our sites, but having the two international sites online has just given them like – given us that extra opportunity to enroll. There's nothing other than number of sites that believe impacting positively our enrollment..

Okay. And last one maybe a financial question, with the increasing number of pipeline products now expecting to enter the clinic or entering the clinic.

How should we think about expenses to round out the year and into 2021?.

Brian?.

Sure. So I think we reiterated on this call that our current cash position of $271 million provides us more than two years runway on our current operating plan. We also have a line of credit that we can pull down, but I think you've seen pretty disciplined capital allocation over the previous quarters.

And we're very careful to show you in our earnings releases, what our cash used in operations as each quarter.

And that can give you an idea of where we stand and as we embark on a registration study and preparing for a BLA, I think that reasonable assumptions can put you in the ballpark of where we expect that cash used in operations to be in the future..

Okay. Thank you very much..

Thank you. Our next question comes from Mike Ulz with Baird. Your line is open..

Hey guys. Thanks for taking the question. I just had a follow-up on lung cancer and in particular, 1592. So you guys are still dose escalating here. Just curious if you can maybe talk about the doses you're planning to test there and then how those compared to 1536. Just wondering if you're maybe trying to get to a higher dose with 1592? Thanks..

Yes. So we will be – obviously, it’s a three plus three design, we'll be pushing to reach the maximum tolerated dose. I think we expect to look – we will be looking not only at the dose level, but also the exposure, preclinical data has showed that at the same dose, we are getting higher exposure from 1592.

So we will be looking at what is the MTD, how does that MTD compare with 1536? What is the exposure of the MTD and how does that compare to the exposure of 1536? So all these are important pieces of information as we assess the clinical differentiation of 1592 over 1536, we'll be looking at the tolerability profile and comparing the two as well as the different dose levels.

So there is a lot to learn over the next few months on the comparison of the two molecules..

Got it. Thank you..

But it could be very exciting if we can see the differentiation we saw in preclinical models in the clinic with 1592, because it's – as you've seen 1536 already has a very exciting profile..

Yes, makes sense. Thank you..

Thank you. And I’m currently showing no further questions at this time. I'd like to turn the call back over to Anna Protopapas for closing remarks..

Just want to thank everyone for joining us today. I welcome you joining us at the webinar, we will be having to talk about the Immunosynthen, and of course, stay tuned for details of our Analyst and Investor Day around year-end. Thanks again..

Ladies and gentlemen, this concludes today's conference call. Thank you for participating. You may now disconnect..