Ladies and gentlemen, thank you for standing by. My name is Desiree, and I will be your conference operator today. At this time, I would like to welcome everyone to the Merus conference call. All lines have been placed on mute to prevent any background noise. After the speaker's remarks, there will be a question-and-answer session. If you would like to ask a question during this time, simply press Star followed by the number one on your telephone keypad. If you would like to withdraw your question again, press the Star one. I would now like to turn the conference over to Kathleen Farren from Merus Investor Relations. Please go ahead. Good morning from Boston. Thank you for joining our call. The purpose of this call is to discuss the abstracts released yesterday ahead of this year's ESMO Asia Conference. We will also provide a program update. The slide presentation is available on our website at www.merus.nl. On this call, we will also make certain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. These may include statements about our future expectations and plans, and events and circumstances, including about finances, intellectual property, projections about Merus's clinical development for 2023 and beyond, and the timing for plans and for meeting clinical and regulatory anticipated milestones related to MCLA-129, petosemtamab, zenocutuzumab, and our other Biclonics candidates. Each forward-looking statement is subject to risks and uncertainties that could cause actual results and events to differ materially from those projected in that statement. A more complete description of these and other material risks can be found at Merus's filings with the United States Securities and Exchange Commission, including its Form 10-Q for the period ended September 30, 2023, which we filed with the SEC on November 2, 2023. Leading us through the agenda will be Dr. Bill Lundberg, Chief Executive Officer, and Dr. Andrew Joe, Chief Medical Officer. Bill? Good morning from Boston. Merus is an oncology-focused company with four clinical assets of our own and multiple other clinical assets we've developed with our collaborators and licensees. Of our own, three have already shown encouraging clinical data. At Merus, we've been innovators in the field of multispecific antibodies for over a decade, with our proprietary Multiclonics technology platforms that allow us to make bispecific and trispecific antibodies. Like monoclonal antibodies, a single cell produces essentially a single multispecific antibody. This allows us to leverage the decades of experience with monoclonal antibody discovery and development, including high-throughput screens, manufacturability, large-scale production, global availability of contract manufacturing of monoclonal antibodies, and is fully human IgG1. Our molecules are designed to have predictable in vivo behavior, low immunogenicity, and consistent half-life, and can have all the Fc domain engineering, like ADCC enhancement or stealth silencing for T-cell engagers, among other modifications. This is a powerful technology platform, and while it doesn't guarantee success in the clinic, we believe it gives us a better chance of being successful. As one example, we're looking forward to discussing the abstracts published yesterday for MCLA-129 to be presented at ESMO Asia in the beginning of December. On today's call, our CMO, Dr. Andrew Joe, will discuss the MCLA-129 data provided in the abstract for ESMO Asia. I will then discuss how these data fit into the treatment landscape and our go-forward plans for MCLA-129. I'll wrap up the call and take your questions. We developed MCLA-129 as a bispecific antibody to attack both EGFR, a well-established driver of lung cancer, and c-MET, a key treatment resistance mechanism. We discovered MCLA-129 using an empirical biological screen to identify what we believe to be the best bispecific antibody based on multiple biologic assays, characterizing inhibition of proliferation and migration, and overcoming resistance of cancer cells to a first-generation TKI. MCLA-129 works by blocking ligands binding to both EGFR and c-MET receptors, inhibiting receptor dimerization and downstream receptor phosphorylation and signaling. It also possesses enhanced antibody-dependent cellular cytotoxicity, or ADCC. At AACR 2023, we shared preclinical data demonstrating that MCLA-129 was more potent in ADCC against cancer cells than amivantamab with certain effector cells. At the EORTC, NCI, AACR triple meeting just about a year ago, we shared our early encouraging efficacy and safety of MCLA-129 in dose escalation. The next slide is a reminder of the interim data we presented at last year's EORTC, NCI, AACR annual meeting. The left panel describes the completed dose escalation cohort in which the 1500 mg every 2 weeks recommended phase 2 dose was determined and the initial expansion cohorts that were opened at that dose. The middle panel shows the safety table for the dose escalation cohort in which no dose-limiting toxicities were reported. As of the August 2022 data cutoff date, the most common toxicity was infusion-related reactions, which was a grouped term and which occurred almost exclusively during the first infusion, and there were no reported cases of interstitial lung disease, also known as ILD, including pneumonitis. The right panel shows the waterfall efficacy plot, in which antitumor activity was demonstrated in previously treated non-small cell lung cancer patients with various EGFR and MET mutations and in the head and neck cancer patient. The next slide describes the data published in the ESMO Asia abstract on the MCLA-129 and osimertinib combination in two non-small cell lung cancer cohorts. Please note that updated clinical data with additional patients and a later data cutoff date will be included in the mini oral presentation at ESMO Asia next week. As of the May 10, 2023 data cutoff date, 48 patients with non-small cell lung cancer were treated with MCLA-129 in combination with osimertinib. Fourteen patients were treatment naive and were treated in the first-line setting, and 34 patients who were previously treated with osimertinib were treated with the MCLA-129 combination in the second-line-plus setting. In the first-line setting, among the 10 patients evaluable for efficacy, 2 confirmed and 6 unconfirmed partial responses were observed, and all responses were ongoing at the data cutoff date. In the second-line-plus setting, among 22 patients evaluable for efficacy, 6 confirmed and 5 unconfirmed partial responses were observed. Nine of the 11 responses were ongoing at the data cutoff date, including 4 of the unconfirmed partial responses. In an early preliminary assessment of the Phase 1b of the MCLA-129 osimertinib combination, the most common adverse events, regardless of causality, were infusion-related reactions, a group term, in 85% of patients, with 6% Grade 3 or higher. Skin adverse events were observed in 75% of patients, with 4% Grade 3. Treatment-related ILD was reported in 5 patients, 10%. As of the data cutoff date, two were Grade 2, two were Grade 3, and one was Grade 5, and one patient with ILD progressed to Grade 5 after the data cutoff date. Venous thromboembolic, or VTE, events were observed in seven patients, 14.6%, of which two cases, 4.2%, were assessed as treatment-related. VTEs have been reported previously in lung cancer and in lung cancer patients who have been treated with a range of different therapies, including osimertinib or EGFR MET bispecific antibody therapy. Our initial assessment of these cohorts is that MCLA-129 is a very active drug in both first-line and second-line non-small cell lung cancer when combined with osimertinib, and we have continued to explore other potential opportunities and areas of differentiation. On the safety side, we are developing approaches to manage the safety risks, including EGFR-type toxicities, ILD, and VTE. The next slide describes the abstract data from the head and neck cancer cohort. These data will also be updated with additional patients and longer follow-up in the poster presentation. As of our May 10, 2023 data cutoff date, 18 patients with previously treated head and neck cancer were enrolled, of whom 12 were evaluable for efficacy. The median number of lines of prior therapy was two, which included anti-PD-L1 therapy in 78% of patients, platinum-based chemotherapy in 89% of patients, and cetuximab in 28% of patients. Clinical activity was observed in this cohort, with two unconfirmed partial responses, or 17%. The safety profile was manageable, and there were no reported cases of ILD or VTE. Our initial assessment of this cohort is that the clinical activity of MCLA-129 in second-line-plus head and neck cancer appears substantially inferior to that of our lead asset, petosemtamab, the EGFR and LGR5 bispecific antibody, and only on par with cetuximab with such monoclonal antibody drugs. This efficacy is insufficient to warrant further development in head and neck cancer. Putting this all in perspective, MCLA-129 is a very active drug discovered and developed from our proprietary Biclonics platform, and we believe it is yet another validation that Merus generates drugs that have real potential for patients. We believe these data for MCLA-129 with osimertinib in front-line non-small cell lung cancer are comparable to other recently published results, for example, the MARIPOSA-1 regimen. The treatment landscape in the front-line setting is evolving, including a potential role for an EGFR-MET bispecific antibody. We also recognize that based on the competitive landscape and investment required, further development of MCLA-129 in front line would only be possible with a partner. In second-line non-small cell lung cancer, we believe our efficacy data with MCLA-129 and osimertinib thus far appear to be quite similar to the combination of amivantamab and lazertinib in the same setting shown in the CHRYSALIS study. ... Here, too, the field is evolving. The MARIPOSA-2 study suggests that a combination of an EGFR MET bispecific with chemotherapy has the potential to be a more effective regimen than in combination with a TKI, with or without chemotherapy. We believe MCLA-129 may also have the potential to be differentiated in this setting, and we're planning a focused investment to evaluate MCLA-129 in combination with chemo, which is planned to start early in 2024. On the safety side, for the combination of MCLA-129 with osimertinib in non-small cell lung cancer, we did observe infusion-related reactions, as well as skin toxicity, ILD, and VTE, as described earlier. In previously treated head and neck cancer, we view the clinical activity with MCLA-129 monotherapy as of the cutoff date as modest, with two unconfirmed partial responses, or 17%. The safety profile was manageable, and there were no reported cases of ILD or VTE. Our initial assessment of this cohort is that the clinical activity of MCLA-129 in second-line head and neck cancer appears substantially inferior to that of our lead asset, petosemtamab, the EGFR and LGR5 bispecific antibody, and only on par with other EGFR or cetuximab-based monoclonal or bispecific antibodies as monotherapy in a similar setting. This efficacy is insufficient to warrant further development in head and neck cancer. As we continue the development of MCLA-129, we're taking a disciplined capital allocation approach, making modest but meaningful investments in the program to identify areas of potential differentiation. Of course, we remain open to partnering opportunities as a means to maximize the potential benefit MCLA-129 may have for patients. We are in a fortunate position to have a strong balance sheet. We also recognize the importance of being responsible with our resources to maintain financial strength over the coming year. We have a clear winner in our portfolio. Our priority as a company is to fully resource petosemtamab, our lead asset, with compelling clinical activity in head and neck cancer, an area of significant unmet need with the potential to benefit thousands of patients each year, where the global market is estimated at almost $5 billion in head and neck cancer alone. At Merus, this past year, we've made significant progress across multiple programs and strengthened our balance sheet. We're in a great position for 2024. We've now shown very strong activity for three of our clinical-stage assets, each of which we developed based on our own proprietary Multiclonics technology platforms. For MCLA-129, we have identified focused investment opportunities. We continue to follow patients with EGFR mutant non-small cell lung cancer, treated with MCLA-129 in combination with osimertinib, to evaluate potential for biomarkers as a means to maximize efficacy while proactively addressing safety signals seen to date. We will start a cohort of MCLA-129 in combination with chemotherapy in lung cancer in the first quarter of next year. Additionally, we remain interested in cohort B, evaluating MCLA-129 in patients with MET exon 14 skipping non-small cell lung cancer. Zeno, our most advanced molecule, continues to progress towards potential commercialization. At the ESMO conference in Madrid in October, we published interim data that showed consistent strong efficacy and safety in NRG1 fusion non-small cell lung cancer and pancreatic cancer. And we've guided that we expect to have sufficient clinical data by first half 2024 to support potential BLA submissions. We are actively discussing Zeno with potential commercialization partners, which we view as an essential step in bringing Zeno to patients with NRG1 lung and pancreatic cancers and potentially beyond. Petosemtamab, our lead asset in second-line head and neck cancer, we've shown at AACR earlier this year, interim data demonstrating strong efficacy that has been observed to be far better, in our opinion, than the comparable standard of care. In frontline head and neck cancer, we see a compelling opportunity for petosemtamab in combination with Keytruda, also an area of significant unmet need. I'm really looking forward to 2024. Thank you for your attention. I will now turn the call back over to the operator for questions. Thank you. The floor is now open for your questions. To ask a question this time, please press star, then the number one on your telephone keypad. You'll be provided the opportunity to ask one question. We'll pause for just a moment to compile the Q&A roster. Our first question comes from the line of Tara Bancroft with TD Cowen. Your line is open. Hi, good morning. So I'm wondering from a strategy perspective for 129, what would you have to see in order to be confident in a potential accelerated approval in either the front line or second line? And when you speak to potential partners, what are they looking for or most interested in seeing? Thanks. ... Good morning, Tara. Thank you for your question. So regarding MCLA-129 and the potential path to approval, I think it's important to note generally the landscape of approval is evolving, from an accelerated approval standpoint with the FDA's initiative around FrontRunner and asking companies to move more towards randomized trials that could lead to accelerated approval, as opposed to single-arm trials. In order for us to move into registration-directed trials in the frontline setting, I think we've been pretty clear on this call that a partner would be an important step in the frontline setting. In the second, third line setting, we would want to see compelling clinical data and competitive differentiation to encourage us that MCLA-129 really has the opportunity to be a winner in this setting. So I think as we've indicated on the call, we are initiating cohorts of the combination of MCLA-129 plus chemotherapy in the second-line plus setting. That is where the accumulated data that we've received over the past several months indicates where the best efficacy is in EGFR mutant lung cancer after patients progress on osimertinib or Tagrisso. Next question comes from the line of Tazeen Ahmad with Bank of America. Your line is open. Hi, good morning. Thanks for taking my question. Can I just get a clarification on your cash runway? So you talked about having enough to, you know, around 2027. What portion of that, if any, is relying upon finding a commercial partner for Zeno, or are those two completely different scenarios? Thanks. Morning, Tazeen. Thanks for the question. We have a strong position financially, and we've indicated our runway is into 2027. This includes our most recent financing over the summer and the recent update at the end of the quarter. This accounts for a relatively standard conservative approach to forecasting. Everything is included for the next 12 months. In addition, we have committed to a second, third line cetuximab head and neck cancer registration trial, and that is fully included. Specifically with respect to your question about does it also include zenocutuzumab expenses, we've indicated that it's essential for us to find a partner with whom to commercialize zenocutuzumab, and we still believe that to be the case. Our next question comes from the line of Maury Raycroft with Jefferies. Your line is open. Hi, good morning. Thanks for taking my question. Wondering if you can talk more about what you've learned so far in terms of mitigating some of the on-target safety events, including IRRs, skin tox, and ILDs. And for IRRs specifically, will you make any adjustments to your strategy to administer the full dose on the first day? So we saw a number of safety observations in this data set. With MCLA-129, we do see infusion-related reactions. I will note that while most patients do get some degree of infusion-related reactions, the very low rate of grade 3 or greater is quite encouraging and suggests that we can administer these types of drugs to patients with a full dose on the first day. The other safety observations that we have identified, that we've noted here are the EGFR type of adverse events, and we do seem to have a relatively lower rate of them in monotherapy and a higher rate in combination with the two EGFR-targeted drugs. We've also noted ILD and VTE in the presentation, and these are all safety events that we're working hard to fully understand to decrease the risk of or mitigate the events. But specifically coming back to your original question, we do think that we can give the first dose of MCLA-129 as a full dose on day one, based on all the work that we're doing with our clinical trial sites and clinicians. Next question comes from the line of Etzer Darout with BMO Capital Markets. Your line is open. Great, thanks for taking the question here. I just wondered, for the study that you're planning with 129 and chemotherapy, would that be a randomized study or sort of a single-arm study? And given where the sort of space seems to be moving, maybe more towards sort of a subcutaneous formulation, amivantamab, if maybe you could comment on if and where you are with potentially moving the IV dosing of 129 to sub-Q. Thank you. So for both of those questions, with respect to the first question, we are currently contemplating single-arm cohorts of MCLA-129 in combination with chemotherapy in previously treated EGFR-mutant non-small cell lung cancer. It's really designed as signal finding to understand what the point estimates are for efficacy, response rate, what the safety profile looks like. And typically, our cohort sizes, as you've heard me say many times, are around 20 patients or sometimes up to 40 patients, the cohort sizes that we have run in our signal-finding clinical trials. And I'm sorry, Etzer, what was the second question again? The subq, right. We do note that amivantamab has been developed initially as an IV and gotten approval as an IV, and now it's moving towards an alternative form of route of administration, subcutaneous, which does mitigate a fair number of the safety considerations. This is a really important observation to us. Typically, drugs do get approved initially as an IV route of administration, and then subsequently, additional routes of administration are explored. So that is an important observation for us. We haven't disclosed ongoing or future activities with respect to alternative formulations, but we do note it's an important component of the program. Our next question comes from the line of Charles Zhu with Guggenheim Securities. Your line is open. Hey, guys. Good morning from New York. Given the data you have on hand, what are some of the areas where you could, you know, highlight areas of, clinical differentiation between 129 and amivantamab? And perhaps as a related follow-up, I may have missed it, but any commentary you can make on MET-related toxicity, such as hypoalbuminemia or edema? Thank you. Thanks, Charles. Good morning from Boston. With respect to the second question, c-MET-related toxicities, we have not seen a significant or substantial signal of c-MET-related toxicities in the data that we shared, either here in these datasets or in the previous dataset we shared in dose escalation. But it is something obviously we're paying attention to and keeping an eye on. And the first part of the question was areas of differentiation for MCLA-129. We've shared preclinical data previously around our molecule being potently ADCC-enhanced, and in particular, having efficacy against c-MET driven cancers or c-MET resistance in cancer models against particular or with the particular effector cells. We still think that is an area where there could be potential differentiation with respect to our molecule as compared to amivantamab. We do believe that in the second-line setting, we need to evaluate that in the context of our drug in combination with chemotherapy, which is why we have these focused investments in specifically MCLA-129 plus chemotherapy in the second-line plus setting in EGFR mutant non-small cell lung cancer. Next question comes from the line of Brad Canino with Stifel. Your line is open. Good morning. I just wanna check in, when might you have the biomarker analysis for the second line cohort? And then also, do the biomarkers have a potential role for the chemo combo as well? Thank you. Thank you. So with respect to the biomarker analysis, that is ongoing and we continue to analyze a range of biomarkers, predominantly those that are most relevant for the expression of the two target molecules, EGFR and MET. In the clinical presentation in a week at ESMO Asia, it contains biomarker information, and we will continue to follow and continue to analyze additional biomarker data of the patients who are ongoing and currently being treated in the coming months. We think those are important elements that will help inform our understanding of the molecule. We do also think that there is a potential role for biomarkers to identify patients more likely potentially to respond in the combination of MCLA-129 plus chemotherapy, but of course, that's a data-driven analysis. It is something that we think will be important to look at. Next question comes from the line of Yigal Nochomovitz with Citi. Your line is open. Yeah, hi, thanks very much for taking the question. Could you just comment a little bit on the plan with the combo of 129 and chemo, and what gives you confidence that that safety profile could potentially look better than what you've seen so far with the data presented today? Thanks. Thank you, Yigal. One of the advantages of having data on a different EGFR c-MET bispecific is that it's quite informative for us. So we do note that in the CHRYSALIS study, the combination of amivantamab plus TKI lazertinib, the response rate is around 35%-36% as a relevant benchmark. However, the additional studies that have been done with amivantamab, particularly MARIPOSA-2, has shown a response rate north of 50% when that regimen is combined with, I'm sorry, when amivantamab is combined with chemotherapy, which strongly suggests that EGFR MET bispecific in the second-line plus setting is more potent when combined with chemotherapy rather than with just a TKI. I would offer that we are initiating cohorts first quarter of next year, so we will be testing MCLA-129 with chemotherapy starting in the first quarter of next year, and it just takes, you know, a good number of months to enroll and then follow patients to evaluate them. We haven't guided the timing of readout any further than that. Next question comes from the line of Ami Fadia with Needham. Your line is open. Hi, good morning. Thanks for taking my question. Could you provide us an update on the enrollment for the MET exon 14 cohort? And maybe just stepping back, you mentioned that you would look for a partner for a first-line development. Would that be for any line as well, or are you sort of thinking about pursuing a second-line registration trial on your own? Thank you. Good morning, Ami. The MET exon 14 driven non-small cell lung cancer cohort, we did indicate that we did not have sufficient enrollment at the time we needed to submit an abstract for presentation at ESMO Asia, and we have indicated we are currently continuing to enroll that cohort. Our cohort sizes are around 20 or sometimes up to 40 patients. So you can infer, you know, we're continuing to enroll, and we're working hard on that enrollment. With respect to partnering, we've been quite clear that further development in the frontline setting would be difficult without a partner, and we've also indicated we're open to partnering the program as a whole. To the point that you're making, it would be very difficult to try to split the baby and have a partner only for a particular indication for a molecule. That doesn't make any sense. A partner, you know, in principle, would be a partnership for MCLA-129 development. Next question comes from the line of Matt Phipps with William Blair. Your line is open. Good morning, Bill. Thanks for taking my questions. I was wondering, there was a presentation at ASCO that suggested VT events with amivantamab and TKI might be related to response or correlated, I guess, with response. Wondering if you saw that? And then also with the ILD-related reactions, is there any correlation with prior therapy, such as exposure to radiation? Thanks, Matt. With respect to the venous thromboembolic events, our numbers are small, so it's hard to define any statistically significant correlation, and it's too early yet for us to say whether or not there's a relationship with response and the VTE events that we have observed, but we're continuing to monitor that. With respect to ILD, I think there is a general sense in the field that ILD is often associated with cumulative toxicity to the lung, whether it's prior radiation therapy or prior systemic cytotoxic chemotherapy, or, you know, as we've seen with ADCs as well, antibody drug conjugates as well. Again, you know, our numbers are small, so, you know, it's, it's hard for us to ascribe a definitive relationship. This is also a really important point we're looking at because ultimately we wanna make sure as we move forward with MCLA-129, that we're able to identify any risks associated with ILD to reduce the frequency or occurrence, or likelihood of occurrence and mitigate any toxicities associated with ILD. Next question comes from the line of Sebastiaan van der Schoot. Kempen, your line is open. Hey, good morning, team, and thank you for taking my questions. I'm just looking ahead into 2024, and I'm wondering about petosemtamab. What are you considering to be currently the benchmark in the frontline setting when you're looking at the combination with Keytruda? Thank you. Good afternoon, Sebastiaan. Thanks for the question on petosemtamab. Well, the first comment I'll make is, like, I think the MCLA-129 data that we see here in head and neck cancer really underscores the notion that MCLA-129 appears to be like these other cetuximab-like monoclonal or bispecific antibodies that we've seen to date, which appears to be substantially different from the efficacy we've seen. Just to remind everyone, 37% response rate in second-line head and neck cancer that we presented at ACR earlier this year. And the cetuximab-like levels of efficacy, only 2 unconfirmed responses in our dataset, we don't believe is sufficient for further development in head and neck cancer. Now, for petosemtamab itself in head and neck cancer, we've talked about how good does that molecule have to be to be an important medicine in head and neck cancer. Head and neck cancer, at the initial diagnosis of metastatic or recurrent disease, is a disease where the current response rates are around 20% for Keytruda alone or 32% with Keytruda chemo, but really only a median survival of little more than a year. So it's a very difficult disease for these patients with this diagnosis, and we're hopeful that if we can take the benefit of Keytruda and add the benefit potentially to petosemtamab, we can substantially improve upon that. From a regulatory standpoint, the trial that compares a combination drug against Keytruda would have the benchmark of Keytruda as the regulatory benchmark. Others have asked if the commercial benchmark might need to be a bit higher, but I think what we have in our in the combination therapy of petosemtamab plus Keytruda is a lot of real opportunity to substantially improve upon Keytruda. And as we've talked about before, multiple other datasets combining an EGFR-type drug with Keytruda really do support the notion that one may be able to get substantial benefit with petosemtamab and Keytruda in combination. That's a brief summary, but I'm sure we'll be talking about it more. There are no further questions at this time. Dr. Lundberg, I turn the call back over to you. So thank you all for your time and attention today, and particularly for allowing us the opportunity to walk through our MCLA-129 initial cohort data that we are presenting now at ESMO Asia. At Merus, we're proud of the progress we're making. All of our molecules based on our innovative and promising Biclonics technology platform on which our company was founded. We're also excited for our near-term opportunities to advance multiple clinical programs towards potential BLA registration and create meaningful value near term for patients and for the company. I'm really looking forward to 2024. This concludes our call. This concludes today's conference call. You may now disconnect.