Q1 2023 Mersana Therapeutics Inc Earnings Call

[music].

Operator: Good morning and welcome to Mersana Therapeutics' first quarter 2023 conference call and webcast. Currently, all participants are in listen-only mode.

It won't come Kumarisami Therapeutics first quarter 2023 conference call and webcast.

Currently all participants are in listen only mode.

Operator: There will be a question or answer session at the end of this call. Please note this event is being recorded. I would now like to turn to the call over to Jason Fredette, Senior Vice President of Investor Relations and Corporate Communications. Please proceed. 

Please note this event is being recorded.

Jason Fredette: Good morning everyone. Before we begin, please note that this call will contain forward-looking statements within the meaning of federal securities laws. These statements include but are not limited to those related to the therapeutic potential of our product candidates and the potential of our platform business strategy, clinical trial design and execution of data releases, regulatory plans and objectives, commercial opportunities, collaborations, potential associated payments, operating expenses, and cash runway.

of our product candidates and the potential of our platform business strategy, clinical trial design and execution of data releases, regulatory plans and objectives, commercial opportunities, collaborations, potential associated payments, operating expenses, and cash runway.

Isn't this strategy clinical trial design and execution of data releases. Torri plans and objectives commercial opportunities collaborations and potential associated payments operating expenses and cash runway.

Torri plans and objectives commercial opportunities collaborations and potential associated payments operating expenses and cash runway.

Jason Fredette: Each of these forward-looking statements are subject to risks and uncertainties that could cause actual results to differ materially from those projected in such statements. These risks and uncertainties are discussed in our annual report on Form 10-K filed with the Securities and Exchange Commission on February 28, 2023, and in subsequent SEC filings.

Jason Fredette: Our filings are available at sec.gov, and on our website mersana.com. Except as required by law, we assume no obligation to update forward-looking statements publicly even if new information becomes available in the future.

Jason Fredette: So with that, let me turn the call over to Anna Protopapas, President and Chief Executive Officer.

And Chief Executive Officer.

Thank you, Jason and Hello, everyone welcome to our conference call joining me today with prepared remarks. Box, almost sander Chief Medical Officer. And Chief Financial Officer, Bryan and Sean. We also have management here, who will be available to answer your questions.

Box, almost sander Chief Medical Officer. And Chief Financial Officer, Bryan and Sean. We also have management here, who will be available to answer your questions.

And Chief Financial Officer, Bryan and Sean. We also have management here, who will be available to answer your questions.

We also have management here, who will be available to answer your questions.

She was also 23 is shaping up to be a potentially transformational year for Bruce. We are on the verge of a talk about the data readout for a first in class ADC tweaks, while we also execute other comprehensive clinical development plan for this. To date, we've got potential to address significant unmet medical needs for patients suffering from ovarian cancer.

We are on the verge of a talk about the data readout for a first in class ADC tweaks, while we also execute other comprehensive clinical development plan for this.

To date, we've got potential to address significant unmet medical needs for patients suffering from ovarian cancer.

Well why don't you own pipeline and I'll also collaborated with Cerberus. Other organization. So I think all three proprietary ADC platforms. It takes them about. On the business development front, we are doing all of this on a strong financial footing.

Other organization.

So I think all three proprietary ADC platforms.

It takes them about.

On the business development front, we are doing all of this on a strong financial footing.

We are pursuing all objectives during a historic period for <unk>. As evidenced by numerous new collaboration. Additional approvals exciting UK that presentation and one of the largest biotech equity issuance you did in <unk>.

As evidenced by numerous new collaboration.

Additional approvals exciting UK that presentation and one of the largest biotech equity issuance you did in <unk>.

No worries. Have a good chance. Typically once that talks about just what you said. Got it. Got all the approval pathway. And from a commercial perspective. Okay. For. Everyone's treatment. But the company did classes. And the willingness. She had to embrace or talking to the approach.

Have a good chance.

Typically once that talks about just what you said.

Got it.

Got all the approval pathway.

And from a commercial perspective.

Okay.

For.

Everyone's treatment.

But the company did classes.

And the willingness.

She had to embrace or talking to the approach.

And so there was some. It's a very exciting period. Thanks to a decade of hard work by the team. My son up but it looks like people approach. Great. Okay. And our advanced stage of clinical development with upfront. We believe we are well positioned to add to the momentum in that field.

It's a very exciting period.

Thanks to a decade of hard work by the team.

My son up but it looks like people approach.

Great.

Okay.

And our advanced stage of clinical development with upfront. We believe we are well positioned to add to the momentum in that field.

Yes. We embarked on a strategy with stoppage of tweets about diesel. And we had five. Ongoing clinical trials. The address areas of high unmet medical need. Yeah.

We embarked on a strategy with stoppage of tweets about diesel.

And we had five.

Ongoing clinical trials.

The address areas of high unmet medical need.

Yeah.

The first is the uplift a single arm registration trial in platinum resistant ovarian cancer. Despite a rocketship wrong about trucks. Thank you Tim. Three of them 70 patients in this trial. And we said product uptake in the platinum resistant state admin. Need for these late stage patients. Hi.

Despite a rocketship wrong about trucks. Thank you Tim.

Three of them 70 patients in this trial.

And we said product uptake in the platinum resistant state admin.

Need for these late stage patients.

Hi.

Next phase III clinical trials as a monotherapy treatment. But in recurrent platinum sensitive ovarian cancer. This trial is designed to serve as a post approval confirmatory trial in the U S significantly increase our potential market opportunity. <unk> expansion into a new handbag. This is a therapy. Support potential approval.

But in recurrent platinum sensitive ovarian cancer.

This trial is designed to serve as a post approval confirmatory trial in the U S significantly increase our potential market opportunity.

<unk> expansion into a new handbag.

This is a therapy.

Support potential approval.

And this upgrade. Phase one combination trial of premium coffee lapping impractical. Okay. We hope it stays that way. For our part. So the treatment.

Phase one combination trial of premium coffee lapping impractical.

Okay.

We hope it stays that way.

For our part.

So the treatment.

We talked like data from optic. After the upcoming oncology conference. And a potential PMA submission. We have begun to prepare for potential commercialization. That's enough. Small formed a small core team. Moshe professional with deep program yet. Sometimes maybe come up fast function and we're working diligently to ensure we can hit the ground money market.

After the upcoming oncology conference.

And a potential PMA submission.

We have begun to prepare for potential commercialization.

That's enough.

Small formed a small core team.

Moshe professional with deep program yet.

Sometimes maybe come up fast function and we're working diligently to ensure we can hit the ground money market.

Beyond I'm pleased we continued to make progress in our phase one trial with <unk>. Steve. I'll be seven each for tomo product tragedy and are working toward a clinical hold. FDA. Based on our phase one clinical trial. Thanks to Florida, that's how can you think of classic grid. The call over to art. Thanks.

Steve.

I'll be seven each for tomo product tragedy and are working toward a clinical hold.

FDA.

Based on our phase one clinical trial.

Thanks to Florida, that's how can you think of classic grid.

The call over to art.

Thanks.

Arvin Yang: Thank you Anna. Let's begin by discussing the UpRi.

Let's begin by discussing the uplift.

Arvin Yang: Platinum resistant ovarian cancer remains an area of significant unmet medical need. Patients at this most advanced stage of disease are heavily pretreated and have a very poor prognosis. For most patients, treatment options are limited to single agent chemotherapy which has consistently demonstrated an objective response rate of approximately 12% in previous trials. We're seeking to fill this significant gap in care with UpRi.

At this most advanced stage of disease are heavily pretreated and have a very poor prognosis.

Most patients treatment options are limited to single agent chemotherapy.

Which has consistently demonstrated an objective response rate of approximately 12% in previous trials, we're seeking to build a significant gap.

Kerr with Opry.

Arvin Yang: Following the release of data from aerosol and based on Bevacizumab label, it is worth noting several key differences in our trial populations. In uplift, we enrolled an all commerce population and retrospectively are determining not be to be positive status as compared to Mirasol, which pre selected for folate receptor alpha positive patients. We believe that at least a majority of ovarian cancer patients have not been to be positive expression. In fact, the large snappy [inaudible] dataset that has been presented to date assessing roughly 400 unique tissue samples suggest that 59% of ovarian cancer patients are not [inaudible] positive. In contrast, available data suggests that only a minority of ovarian cancer patients have folate receptor alpha positive expression.

Receptor alpha positive patients, we believe that at least a majority of ovarian cancer patients have not been to be positive expression. In fact, the large snappy <unk> dataset that has been presented to date assessing roughly 400 unique tissue samples suggest that 59% of ovarian cancer patients are not be <unk>.

In contrast, available data suggests that only a minority of ovarian cancer patients have folate receptor alpha positive expression.

In contrast available data suggests that only a minority of ovarian cancer patients have folate receptor alpha positive expression.

Arvin Yang: We also enrolled patients in Uplift who have received one to four prior lines of therapy compared to both Psoria and Mirasol, which enrolled patients who had received one to three prior lines. We believe the differences observed between Psoria and Mirasol served as a reminder how ORR can be influenced by the type and level of patient pretreatment.

Patient pretreatment.

Arvin Yang: We also enrolled patients with grade two underlying neuropathy and [inaudible]. While these patients were excluded from both Psoria and Mirasol, our broad inclusion criteria were based largely on the encouraging data from our dose expansion cohort. Uplift's primary endpoint is the investigator assessed objective response rate or ORR in the [inaudible] positive population. The primary endpoint will aim to exclude the 12% objective response rate for single agent chemotherapy from the 95% confidence interval.

While these patients were excluded from both survive and yourself are broad inclusion criteria were based largely on the encouraging data from our dose expansion cohort.

Uplifts primary endpoint as the investigator assessed objective response rate or or are in the Napa <unk> positive population.

The primary endpoint will aim to exclude the 12% objective response rate for single agent chemotherapy from the 95% confidence interval in.

Arvin Yang: In addition to ORR, we expect the FDA to evaluate duration of response or DLR, along with safety and tolerability in the overall context of the Uplift. In addition to Uplift, we are continuing to enroll patients in our phase III upnext trial. There is a substantial need for new ovarian cancer maintenance treatments as many patients have already exhausted available maintenance options by the time they have recurrent disease. And with the recent label restrictions related to [inaudible] inhibitors this need is only getting larger.

Along with safety and Tolerability in the overall context of the uplift there.

In addition to Opex, we are continuing to enroll patients in our phase III next trial, there was a substantial need for new ovarian cancer maintenance treatments as many patients have already exhausted available maintenance options by the time, they have recurrent disease and with the recent label restrictions related to.

<unk> inhibitors. This need is only getting larger.

Arvin Yang: Upnext is enrolling 350 patients. These patients must be not [inaudible] positive and they must have achieved stable disease or better in response to their prior induction chemotherapy.

Arvin Yang: In recognition of the lack of standard of care and the recurrent maintenance, the trial is randomized in patients two to one to receive UpRi or placebo. Our primary endpoint for the trial is progression free survival or PFS by blinded independent central review.

Kyle it's randomized patients two to one to receive <unk> or placebo. Maryann point for the trial is progression free survival or PFS by blinded independent Central review.

Maryann point for the trial is progression free survival or PFS by blinded independent Central review.

Arvin Yang: Our third ongoing UpRi trial, Upgrade A is evaluating UpRi in combination with Carboplatinum. Historically, the combination of Carboplatinum and Paclitaxel has served as the standard of care in earlier lines of ovarian cancer treatment. However, distinct tolerability challenges, including high rates of severe neutropenia, peripheral neuropathy, and alopecia have limited the ability to dose this combination beyond six cycles.

Historically, the combination of Carboplatin and Paclitaxel has served as the standard of care in earlier lines of ovarian cancer treatment. However.

However, distinct tolerability challenges, including high rates of severe neutropenia peripheral neuropathy alopecia have limited the ability to dose this combination beyond six cycles.

Arvin Yang: In Upgrade A, patients received UpRi in combination with Carboplatinum for up to six cycles of induction treatment and operating them continued as a monthly maintenance mono therapy. We believe the differentiated tolerability profile we observed for UpRi in our monotherapy dose expansion trial without toxicities, commonly seen with other ADC platforms, they positioned it well for use in combination.

In our monotherapy dose expansion trial without toxicities, commonly seen with other ADC platforms. They positioned it well for use in combination we.

Arvin Yang: We were pleased to complete dose escalation in Upgrade A and move into dose expansion in the first quarter and we're looking forward to sharing initial interim data in the second half of this year.

Arvin Yang: Before delving into our other clinical stage cytotoxic ADC, XMC 1660, let's touch on XMC 2056, which is our first two directed immuno symptom sting agonist ADC.

Arvin Yang: In March, we voluntarily suspended our phase one trial of this product candidate following a grade five serious adverse event [inaudible] assay that was deemed to be related to XMC 2056. The FDA then placed the trial on clinical hold. DSA occurred in the second patient enrolled at the initial dose level in the dose escalation portion of the trial and it was obviously quite unfortunate and unexpected.

DSA occurred in the second patient enrolled at the initial dose level in the dose escalation portion of the trial and there was obviously quite unfortunate and unexpected.

Arvin Yang: In recent weeks, we've received plasma PK and cytokine data for the two patients who were dosed in the trial prior to the clinical hold and we're continuing to analyze these data. We're evaluating next steps for the program and we will prepare a response to the FDA's clinical hold letter. We will provide an update on our plans once they've been solidified.

We will provide an update on our plans once they've been solidified.

Arvin Yang: Now, let's turn to XMC1660, our [inaudible] product candidate targeting 7H4. BCP7H4 is a particularly compelling target given its high expression in a variety of tumors and its limited expression in healthy tissue. XMC1660 is equipped with a precise target optimize drug to antibody ratio of six and our [inaudible] lock payload with controlled bystander.

Except to $16 60 is equipped with a precise target optimize drug to antibody ratio of six and October lock payload with controlled bystander.

Arvin Yang: I'm happy to report that we are making good progress in the dose escalation portion of our multi center phase one trial, which is enrolling patients with breast, endometrial, and ovarian cancers and remain firmly on track to complete this portion of the trial later this year.

Arvin Yang: With that let's turn the call over to our Chief Financial Officer, Brian DeSchuytner for an update on our financials. Brian?

Brian C. DeSchuytner: Thank you Arvin. We are approaching our upcoming top line data readout in a strong financial condition. Beyond the $170 million in upfront payments we received from collaborations over the past year, we're beginning to see the downstream benefit of those transactions in the form of initial discovery milestone revenues.

Brian C. DeSchuytner: We ended the first quarter with approximately $274 million in cash, cash equivalents, and marketable securities and we also have a line of credit available to US. We expect our available funds to support our operating plan commitments into the second half of 2024, well past several potential milestones of significance.

Brian C. DeSchuytner: It should also be noted that our cash runway guidance does not assume any potential milestone payments from our current collaborations or proceeds, that we may realize from future collaborations. Now for a brief recap of our P&L for the first quarter.

Brian C. DeSchuytner: Net cash used in operating activities was approximately $29 million for the first quarter of 2023. Collaboration revenue for the first quarter of 2023 was $7.8 million compared to $2 million for the same period in 2022. The year over year increase was primarily related to our collaboration agreements with Merck KGA and [inaudible].

I saw <unk>.

Brian C. DeSchuytner: Research and development expenses for the first quarter of 2023 were $47.3 million, compared to $35.8 million for the same period of 2022. Noncash R&D related stock based compensation expense for the first quarter of 2023 was $3.3 million. The year over year increase in R&D expenses was primarily related to higher manufacturing and clinical costs related to UpRi and an increase in head count.

It was primarily related to higher manufacturing and clinical costs related to <unk> and an increase in head count <unk>.

Brian C. DeSchuytner: General and administrative expenses for the first quarter of 2023 were $18.3 million compared to $12.8 million during the same period in 2022. Noncash G&A related to stock based compensation expense for the first quarter of 2023 was $3.1 million. The year over year increase in G&A expense was primarily related to increases in medical affairs, and pre commercial activities and head count.

was primarily related to increases in medical affairs, and pre commercial activities and head count.

Brian C. DeSchuytner: Mersana's net loss for the first quarter of 2023 was $56.2 million compared to a net loss of $47.3 million for the same period in 2022. Now I'll turn the call back over to Anna for a few closing remarks. 

Anna Protopapas: Thanks Brian and Arvin. In summary, 2023 is lining up to be a transformative year for Mersana and we're excited about all that lies ahead. We expect to import top line data for Uplift later this year following the [inaudible] with a potential [inaudible] submission planned for around the end of the year. 

In summary, 2023 lining up to be a transformative year for my side and we're excited by all that nonsense.

We expect to report top line data. It may be that following the major oncology conference. We've got a potential PMA submission plan for a while.

It may be that following the major oncology conference.

We've got a potential PMA submission plan for a while.

Anna Protopapas: We plan to significantly advance enrollment in our confirmatory trial up next. We'll also advance the dose expansion portion of Upgrade A and expect to report initial interim data from this trial in the second half of the year. Our team will continue to work to evaluate next steps related to our development of [inaudible].

We plan to significantly advance enrollment in our confirmatory trial up next week. We'll also advance the dose expansion portion upgrades eight and expect to report initial interim data from this trial. Yeah. Our team will continue to work to evaluate next steps related to our development of <unk>.

We'll also advance the dose expansion portion upgrades eight and expect to report initial interim data from this trial. Yeah. Our team will continue to work to evaluate next steps related to our development of <unk>.

Yeah. Our team will continue to work to evaluate next steps related to our development of <unk>.

Our team will continue to work to evaluate next steps related to our development of <unk>.

Anna Protopapas: And finally, we plan to complete the dose escalation portion of our phase one trial of XMC1660 this year. We look forward to keeping you updated on  all our progress. Now lets open the call to your questions. Operator, would you please provide the instructions?

We look forward to keeping you updated all appropriate now lets open the call to your questions.

Bill would you please provide instructions.

Operator: Thank you. We will now begin the question and answer session. To ask a question, you may press star then one on your touchtone phone. To withdraw your question, please press star then two. At this time, we will pause momentarily to assemble our roster. And today's first question comes from Brian Chang with JP Morgan. Please go ahead.

Operator: To ask a question, you may press star then one on your touchtone phone. To withdraw your question, please press star then two. At this time, we will pause momentarily to assemble our roster. And today's first question comes from Brian Chang with JP Morgan. Please go ahead.

To ensure your question. Please press Star then two. At this time, we will pause momentarily to assemble our roster. And today's first question comes from Brian <unk> with Jpmorgan. Please go ahead.

At this time, we will pause momentarily to assemble our roster. And today's first question comes from Brian <unk> with Jpmorgan. Please go ahead.

And today's first question comes from Brian <unk> with Jpmorgan. Please go ahead.

Brian Chang: Hey, guys, thanks for taking my question this morning. Maybe just one on ASCO-heading into ASCO I saw that you have a presentation on expression of folate receptor alpha and also not [inaudible]. So can you just shed some light on what that presentation entail and what should we be looking for there? And then I have a follow up. Thank you.

Maybe just one on the <unk> heading into <unk> I saw that you have our presentation. There an expression of folate receptor alpha and also not be <unk>. So can you just shed some light on what that presentation entail and what should we be looking for there and then I have a follow up thank you.

Arvin Yang: Thanks, Brian. This is Arvin, I can address that question. So we look forward to sharing information at ASCO. It's a data set that comes from our expansion cohort of our UpRi study, the phase one study. And really the purpose of it is to evaluate not be to be expression and folate receptor alpha expression recognizing that in other data sets external to the one that we're presenting, we've described how [inaudible] is approximately 59% based on 400 tumor samples are relative to what we've seen from the FDA review of [inaudible] where 29% was positivite folate receptor alpha.

It's a data set that comes from our expansion cohort. R R. <unk> studied the phase one study and really the purpose of it is to evaluate not be to be expression and folate receptor alpha expression recognizing that in other data sets external to the one that we're presenting we've described how <unk> is approximately 59% based on <unk>. 100 tumor samples are relative to what we've seen from the FDA review of. But Hudson that were 29% was positivity folate receptor alpha.

R R. <unk> studied the phase one study and really the purpose of it is to evaluate not be to be expression and folate receptor alpha expression recognizing that in other data sets external to the one that we're presenting we've described how <unk> is approximately 59% based on <unk>. 100 tumor samples are relative to what we've seen from the FDA review of. But Hudson that were 29% was positivity folate receptor alpha.

<unk> studied the phase one study and really the purpose of it is to evaluate not be to be expression and folate receptor alpha expression recognizing that in other data sets external to the one that we're presenting we've described how <unk> is approximately 59% based on <unk>. 100 tumor samples are relative to what we've seen from the FDA review of. But Hudson that were 29% was positivity folate receptor alpha.

100 tumor samples are relative to what we've seen from the FDA review of.

But Hudson that were 29% was positivity folate receptor alpha.

Brian Chang: Great. And maybe just one on Uplift topline. Heading into Uplift topline later this year, later in mid year, outside of overall response rate and duration of response, are there any additional efficacy measures that we could get at the top of the top line?

Outside of overall response rate and duration of response are there any additional efficacy measure that we could get at the top of the top line.

Anna Protopapas: So I think as we've said, the top line will be mid year after the June oncology conferences, and we will be showing overall response rate as the primary end point as far as the secondary endpoints duration of response and of course, the key safety overview for the study.

We've said that top line won't be mid year. After the June oncology conferences, and we will be showing overall response rate as the primary end point as far as the secondary endpoints duration of response and of course, the key safety. <unk> overview. Oh. Sure. For the study.

<unk> overview. Oh. Sure. For the study.

Oh. Sure. For the study.

Sure. For the study.

For the study.

Brian Chang: Thanks, Anna. Thank you.

Operator: Thank you. And our next question today comes from Jonathan Chang with SVB Securities. Please go ahead.

<unk> Securities. Please go ahead.

Jonathan Chang: Good morning, thanks for taking my questions. The first question on the recent Mirasol results, how does that impact your thinking on the UpRi opportunity and strategy?

The first question.

On the recent Mirasol results, how does that impact your thinking on the pre opportunity and strategy.

Anna Protopapas: We remain very excited about the UpRi opportunity Jonathan. As you know and it's evident from what we've seen from a unit just as you said this is an area where we have high unmet medical need. There is a desperate need by physicians and patients for new agents and we remain very excited about UpRi. We've shown robust efficacy and a differentiated tolerability profile E&P expansion cohort and of course, as Arvin just alluded to, we have an agent that has a very significantly different prevalence in the overlap between [inaudible] high and [inaudible] high is quite limited. So there is a desperate need for new agents for these patients and we hope UpRi will fill that gap.

As you know and it's evident from.

What we've seen from a unit just as you said there.

We have high unmet medical need there.

There is a desperate need by physicians and patients for new agents and we remain very excited about up pretty well.

We've shown robust efficacy and a differentiated tolerability profile E&P expansion cohort and of course, it's honestly just alluded to we have an agent that has. Very significantly different prep in months and be open up between forming high and not be too high is quite limited. So there is a desperate need for new agents for these patients and we hope upright will fill that gap.

Very significantly different prep in months and be open up between forming high and not be too high is quite limited. So there is a desperate need for new agents for these patients and we hope upright will fill that gap.

Jonathan Chang: Got it. Thank you. And second question, when could we see initial data from the B7H4 program?

Anna Protopapas: What we've guided to, and I think Arvin mentioned on the call is that we expect to complete dose escalation by the end of this year. Our dose escalation is proceeding as planned, and at that point, I think [inaudible] not yet guided to data disclosure, but we're very excited about the program. We think this is a great target for [inaudible] our platform so we'll make that decision on data disclosure as we approach completion of the dose escalation.

What we've guided to it I think we'd mentioned on the call is that we expect to complete dose escalation by the end of this year. Dose escalation is proceeding as planned. And at that point, I think don't forget guided to data disclosure, but we're very excited about the program. We think this is a great target for an ADC. Folks so we'll make that decision on data disclosure. As we approach completion of the dose escalation.

Dose escalation is proceeding as planned. And at that point, I think don't forget guided to data disclosure, but we're very excited about the program. We think this is a great target for an ADC. Folks so we'll make that decision on data disclosure. As we approach completion of the dose escalation.

And at that point, I think don't forget guided to data disclosure, but we're very excited about the program. We think this is a great target for an ADC. Folks so we'll make that decision on data disclosure. As we approach completion of the dose escalation.

Folks so we'll make that decision on data disclosure. As we approach completion of the dose escalation.

As we approach completion of the dose escalation.

Jonathan Chang: Got it, thanks for taking my questions.

Thank you and our next question today comes from Collyn. Sir Please go ahead.

Sir Please go ahead.

Hi, good morning, and thanks for taking our questions on the uplift. Readout, that's coming up in mid year would you expect to also report data in the overall patient population and do you have any expectations on what you'd need to show that b to b low patient population to get a broad label.

Readout, that's coming up in mid year would you expect to also report data in the overall patient population and do you have any expectations on what you'd need to show that b to b low patient population to get a broad label.

Sure. Thanks Colleen. We do expect to share data not only in the not be to the positive. Population, which is our primary endpoint, but the overall population is a key secondary endpoint. So response rate and the key secondary endpoint could also support a broader indication. This alludes to actually your second question in relationship to what would you need to see in the low population. So keeping in mind that the benchmark for approval for both of these populations in discussion with FDA. It really is a single agent chemotherapy response rates of 12% now that being said there. The response rate in the overall population. We would imagine could not be completely driven by the not be <unk> positive population in order to generate that overall population response rate.

We do expect to share data not only in the not be to the positive.

Population, which is our primary endpoint, but the overall population is a key secondary endpoint. So response rate and the key secondary endpoint could also support a broader indication.

This alludes to actually your second question in relationship to what would you need to see in the low population. So keeping in mind that the benchmark for approval for both of these populations in discussion with FDA. It really is a single agent chemotherapy response rates of 12% now that being said there. The response rate in the overall population. We would imagine could not be completely driven by the not be <unk> positive population in order to generate that overall population response rate.

So keeping in mind that the benchmark for approval for both of these populations in discussion with FDA. It really is a single agent chemotherapy response rates of 12% now that being said there. The response rate in the overall population. We would imagine could not be completely driven by the not be <unk> positive population in order to generate that overall population response rate.

The response rate in the overall population. We would imagine could not be completely driven by the not be <unk> positive population in order to generate that overall population response rate.

We would imagine could not be completely driven by the not be <unk> positive population in order to generate that overall population response rate.

Got it that's helpful. Thank you and then on the upgrade data later this year or are you able to say roughly how many patients you would expect and how much follow up you would expect to have.

Yeah. So. We had announced last year that we had completed or would that we had approximately 12 patients within the dose escalation portion and then in the first quarter of this year. We had indicated that we have completed dose escalation and initiated the expansion phase.

So.

We had announced last year that we had completed or would that we had approximately 12 patients within the dose escalation portion and then in the first quarter of this year. We had indicated that we have completed dose escalation and initiated the expansion phase.

So you can approximate in relationship to how many patients we would.

Have within dose escalation. And the determination will be made just in relationship to how many patients will then be available for presentation in the second half of this year that also gives you some sense of the follow up that would be available for those patients.

And the determination will be made just in relationship to how many patients will then be available for presentation in the second half of this year that also gives you some sense of the follow up that would be available for those patients.

Got it that's helpful. Thank you and then just last follow up on the upgrade study.

That's reading out later, so would the focus there'll be mainly on safety or can you kind of help us set a bar for efficacy and that readout.

Sure. So the primary focus absolutely is it gives a phase one study and it is really driven off the premise that.

<unk> provides a differentiated profile.

With non overlapping toxicities affording us a great opportunity to combine with standard of care Platinum for instance, and.

In addition to that obviously being able to continue the umbrae a portion of it after completion of the six cycles of combination into.

Into the mono therapy, so safety will be the primary focus of this presentation recognizing that the follow up to get into the maintenance may not be sufficient at that time point.

Our plan to present also efficacy for the available information.

But it's in the context, obviously recognizing safety is the primary focus.

Great. Thanks for taking our questions.

Thank you and again if you have a question. Please press Star then the one our next question today comes from Caveri Puma with BTG. Please.

Please go ahead.

Yeah, good morning, and thanks for the upgrades and for taking my questions for the upcoming Astro data for expression studies is.

Is that specifically for platinum resistant population do you expect do you see any changes and not be too be expression or R&D overlap when you move to earlier lines.

Thanks for the question <unk>. So just for context, obviously, we want to share that.

The presentation for <unk>, but as I mentioned earlier this will be on a data set that comes from our phase one study.

And so that included primarily platinum resistant ovarian cancer patients.

There wasn't a proportion of patients that were fourth line plus that could have been platinum sensitive, but again these were a minority of the patients.

But to your second.

Point in relationship to the prevalence of might be to be we shared actually a variety of different.

Presentations in the past.

From tumor bank from our own internal studies that support the consistency of <unk> expression by line of therapy as well as from a local in metastatic site perspective, there I'll remind folks that 59% with the Napa <unk> positivity when looking at one of the largest deals.

Just tumor bank analysis of individual tissue samples of approximately 400 samples.

That's really helpful. Thank you and for the next study.

Well designed but any insight you could provide on addressable patient population how different it is from the platinum resistant market.

And in terms of benchmark, where PFS, what would you expect out of the placebo arm.

So maybe I'll have been cut.

I've talked to the placebo arm that protection here.

The size of the market, we have not given specific numbers, but we do that.

This trial will bring us towards large.

Unmet medical need potentially bulges in platinum resistant.

With a positive upticks trial.

And maybe just before I jump into that placebo effect I'll just comment that given the emerging landscape the PARP inhibitors.

With the recent FDA changes.

Sure.

<unk> inhibitors are no longer a preempted.

Or restricted primarily to the BRCA and HRD positives, we see that actually is increasing the unmet need in that recurrent platinum maintenance setting.

Platinum sensitive maintenance setting.

Just to your second question as far as the.

Activity at the placebo.

One of the best benchmark, maybe the Nova study. So it's a study of our PARP inhibitor in the recurrent platinum sensitive maintenance setting.

And there the placebo arm had a performance a PFS of approximately four five months, but I do want to provide context to that figure because that was a study performed in an earlier time period, where patients may not have received or would not actually received prior piper bed.

In that.

Era, where the study was conducted in addition to that this patient population was less heavily pretreated and once refractory because they did not include stable disease patients to the prior platinum therapy.

In acknowledgment that the PARP inhibitor and platinum.

Mechanism of action has sufficient similarity that they did not want to include stable disease patients for their study as opposed to net what are we doing with these patients.

Got it and maybe one last one on the seven each for E. D. C from the competitive landscape standpoint, and from your experience with Opry and 15 29 can you tell us what advantages the single species Adt's provides.

We didn't hear the second part of your question Youre asking for the differentiation versus other <unk> for N. P. CS Carberry was that the question.

Yes, and you have a in terms of experience with all three and 15 29, which was also a single species ADC.

Just wanted to get some sense what advantages lead homogeneous adc's provides.

Sure I can start and.

If the team wants to add to that so first off we're very excited about piece of an H, Florida. We think it's a good target given the competitive landscape I would argue that others agree with us in relationship to that.

Before diving into that actually let me just clarify we do actually have extensive knowledge.

The <unk> molecule and its differentiated safety profile given that it's the same payload that's utilized in all three.

Again without the severe neutropenia is the ocular toxicities are the neuropathy as well.

We did evaluated also in the $15 92 program I just wanted to clarify that that was a doughnut sinton molecule with the same payload.

Just to clarify it wasn't 15 29.

Now with that being said we are excited about piece of an H for it because it does differentiate relative to.

And I'll flag two different.

Companies that are also developing b seven each for so <unk> is developing a <unk> molecule but.

We have a dar of a homogeneous startups six alluding to sort of the point, you're raising and we believe that through our preclinical data that the <unk> six.

Did have a differential benefit from the standpoint of greater efficacy when looking at our preclinical models in.

In addition to that we do expect that from a peeler perspective, it'll have that differentiated safety profile relative to the MMA. The CJ molecules being developed at an where they also have a lower dollar of approximately three and a half.

So I think that addresses your question just as far as the differentiated profile.

Yeah, that's very helpful and yeah, I meant 92 F 'twenty nine sorry about that.

No problem yeah.

Thank you next question today comes from Ashish <unk> with Citi.

Please go ahead.

Thank you and thanks for taking my questions.

I know you made some comments related to building out the commercial commercial infrastructure.

In the past quarter, but can you comment at all on the size and the reach of the sales force for upper and you're building out.

And maybe any general commentary on how much of an educational uplift.

You think there needs to be what they might be to be biomarker testing and the sort of real world setting.

So our commercial efforts are very much focused on.

We launched our cubic piece, we're some ways away from really defining the exact size and details of the sales force.

So let me focus on what we are doing now we have a very small but impactful medical affairs group that is really working.

With investigators to increase the awareness of the importance of <unk> as a biomarker and to educate on our pre as a potential therapy in ovarian cancer. So we have really.

Handful of people with deep ovarian cancer commercial expertise that are really preparing the market.

And ensuring that our diagnostic is available all day, one so that is the effort a very small group of people.

<unk> been very impactful.

And ensuring all the work you've done for us to be ready with positive data, where the PMA and then potentially in upcoming approval to be able to build up that effort.

Got it that's really helpful I'm going to ask one more also on the commercial plan I think in the past you've alluded to your plan to partner up in Europe and in other regions globally and I'm. Just wondering if you can remind us why that's the right move I think immunogen made some commentary last week related to the idea that the European Mark.

It was actually pretty concentrated around the <unk>.

Limited number of centers, which which cover maybe covers the majority of the market.

So I'm wondering why if you think I was thinking about the European opportunity and a similar or a very different way given youre planning to partner.

Alright.

Our thoughts are really based on.

Extensive experience across the biotech industry.

Really investing in an infrastructure in Europe .

Although we're bench really might be might pay off since a significant investment and as you are aware getting reimbursement in Europe always takes time, so by the time that European infrastructure becomes cash flow positive it takes them longer to get there that in the U S.

And I think that's what's driving our thinking which of course would be refined as we get top line data will be further refined but I think history will say that small biotech companies that expand to both the USA Europe Chad.

Would require significantly better but before that commercial infrastructure can really begin to be cash flow positive.

Got it thanks for taking my questions.

Thank you and our next question today comes from Boris <unk> with Cowen. Please go ahead.

Great. Thanks for taking my questions. The first question on the uplift study can you set expectations for duration of response and if that is something that you've discussed with the FDA. What the agency may be looking for in terms of duration of response.

Thanks for the question Brian .

And discussions with FDA, we've aligned that response rates.

Endpoint for evaluation of efficacy.

That's 12% based upon the multiple phase III studies that we've described in the past.

Duration of response, certainly will be expected it'll be like context again of the overall efficacy and safety profile that it'll be taken into context.

Oh, great and maybe in terms of baseline characteristics. You mentioned that you allowed baseline great to where it gets lower neuropathy and the uplift trial. While these patients were excluded from Surrey and Mirasol. Just curious can you comment what fraction of these platinum refractory patients have this baseline neuropathy.

So we know that most of the patients actually if not all of the patients.

That become platinum resistant.

We will have received an agent that can induced neuropathy.

Given that tax always a heavy offender and other chemotherapy certainly contribute tribute to that.

I don't have the numbers specifically for the expansion data available in reference to that but based on what I. Just described earlier is that we do expect a fair proportion of patients that have some degree of neuropathy.

That could obviously be impacted if they were to receive further therapy that could cause.

Neuropathy, whereby with operate we have not seen the severe neuropathy.

Great. Thank you very much for taking my questions.

Yeah.

Thank you and our next question comes from.

Ordinary with tourist please go ahead.

Hi, guys. Good morning, Thanks for taking the questions.

So the Mirasol study the all are surprised us positively getting to the 40% plus.

Plus range.

I guess, one could attribute that to being.

Decided recruiting a multiple homogenous population than the phase, one and potentially a less sick patient population then suraj.

Already set a very high bar with all our phase one expansion works so would it be unreasonable to expect youll or ought to look better uplift as well.

Well. Thanks for the question, we saw robust activity expansion cohort, particularly with the 36 milligram.

Cause me to square, but I think the differences in the overall response rate between May result in some right to.

To serve as a reminder, that the type and level of patient pretreatment can influence impact and again as Arvind mentioned on the call we do.

A population that is more heavily pre treated <unk> and definitely even more heavily pretreated mirasol. So I think we'll have to wait and see.

Results midyear.

But I'm confident based on the robust activity, we saw in the expansion cohort.

Great. Thanks, Scott and then maybe just a quick two quick questions.

Do you plan to report the upgrade a data at.

At a medical meeting or would that be more geared towards the investment community and then on the diagnostic test.

<unk>.

Our kols that suggested that there was some bottlenecks.

Faced with.

With the diagnostic tests.

Another customer.

With with one of the centers in particular.

For a while to turn the question around what have you learned from that from a competitive experience and what are you doing to kind of.

Michelle if you don't mind just initiatives. Thanks.

On the diagnostic we're working with our diagnostic partner to ensure that the test is available on day, one and that we are appropriately prepare in terms of supply of reagents to ensure there is no disruption.

The test.

And what was the other question the other what's the second question Guy can address the first question just as far as upgrading.

Indicated that we will share the data in the second half of this year, we have an express sort of one <unk>.

Type of form that will be in and we will disclose at the appropriate time.

Okay. Thanks, a lot guys.

Thank you.

Awesome, David Gordon with Wedbush Securities.

So maybe as a follow up on the diagnostic or the testing question is just if you had any particularly updated thoughts on how physicians would when presented with a patient and then early airlines are and I guess any any line of setting.

You know react to the patients.

Tests with full late first or are they going to do both tests do you think you know kind of how you know.

And treat appropriately you know kind of how.

How do you see that evolving with.

Positive mirasol results. Thanks.

We are very encouraged by the testing that is taking place with with following positive patients.

And we believe that what will happen once both agents are that market is that when a patient diagnosed with ovarian cancer. So they will undergo a set of tests that will include both fall late and that b to b and that is done.

Uh huh.

Sort of state of affairs in the future and I think the uptake we've seen on the falling test is encouraging that.

It will be that won't be the case.

Got it.

And David we are definitely working to make sure that our test is available all day.

And quite often the arch for anyone at any stage, who wants to take the test at any stage of therapies.

Yep.

Great. Thank you.

Ladies and gentlemen, as a reminder, if you'd like to ask a question. Please press Star then one.

Our next question is a follow up from crawling QC with Baird. Please go ahead.

Hi, Good morning, again, thanks for taking the follow up just one more so on the uplift readout and kind of understanding that the patient pre treatment is going to impact the or can you remind us how many patients in the dose expansion, where fourth line or later and would you expect that proportion of patients to be similar or different than the upper.

Study.

Thanks for the question so.

<unk>, 33% of the patients in the expansion.

Portion of the Phase one study for <unk>.

Fourth line or later.

Obviously, we'll disclose the broader demographics at the top line per se, but for context.

<unk>.

<unk> enrolled in the U S as well as in the EU for the uplift study globally in relationship to the uplift study, but we would expect practice patterns to be relatively similar in the platinum resistant space.

Let me now we've got one.

One point, that's why I said, we wont so robustly in uplift I think Mike gave us an opportunity to look at.

<unk> impacts overall response in subgroup analysis.

It really help us better understand the profile of the age.

It.

Great. Thank you.

Yeah.

Concludes our question and answer session.

The conference back over to Ed I'd put a purpose for any closing remarks.

Thank you operator, and thanks to all those listening and for all.

Your continued support we are looking forward to participating in the bank of America Healthcare Conference Tomorrow sharing several poster presentations at Ash next month.

Presenting it and Jeff.

Kept conference a few days later hope to see many of you are dosing pets and joined the rest of the day.

Thank you ladies and gentlemen. This concludes today's conference call. We thank you all for attending today's presentation.

You may now disconnect your lines and have a wonderful day.