Good morning, and welcome to ImmunoGen's third quarter 2021 financial and operating results conference call. Today's conference is being recorded. At this time, I'd like to turn the call over to Courtney O'Konek, Senior Director, Corporate Communications and Investor Relations. Please go ahead. Good morning, and thank you for joining today's call. Today, we issued a press release that includes a summary of our recent progress and third-quarter 2021 financial results. This press release and a recording of this call can be found under the Investors and Media section of our website at immunogen.com. With me today are Mark Enyedy, our President and CEO; Anna Berkenblit, our Chief Medical Officer; and Susan Altschuller, our CFO. During today's call, we will review key recent accomplishments for the business, our financial results, and anticipated upcoming events. During the discussion, we will use forward-looking statements with respect to our business strategy, the development and benefits of our product candidates, the presentation of clinical data for our product candidates, the anticipated timing of regulatory submissions to the FDA and EMA for certain product candidates, our 2021 financial outlook, and our projected cash runway. This information is subject to risks and uncertainties. Our actual results may differ materially from such statements and include those described in the Risk Factors section of our most recent annual report on Form 10-K and our other SEC filings. With that, I'll turn the call over to Mark. Thanks, Courtney. Good morning, everyone, and thank you for joining us today. In the third quarter, we advanced our pipeline and continued our pre-launch activities as we look to transform ImmunoGen into a fully integrated oncology company in the coming year. Starting with our lead program, mirvetuximab soravtansine in platinum-resistant ovarian cancer, I am pleased to say that we are on track to report top-line data from our pivotal SORAYA study this quarter. For this release, we expect to include data on the primary endpoint of overall response rate as assessed by investigator, the sensitivity analysis of overall response rate as assessed by blinded independent central review, the key secondary endpoint of duration of response, and the safety and tolerability profile of mirvetuximab. We believe these data will provide a comprehensive picture of the results of the trial. We are planning for success with SORAYA, and to that end, our preparations for the BLA are well underway with the goal of submitting the application before the end of Q1, along with activities in support of the potential launch of mirvetuximab in the second half of next year. In addition to SORAYA, we are pursuing a broad program to establish mirvetuximab as the new standard of care for patients with folate receptor alpha-positive ovarian cancer. Our confirmatory MIRASOL trial continues to enroll, and we expect top-line data in the third quarter of next year. If positive, these data could enable full approval of mirvetuximab in the U.S., and importantly, support an application for marketing authorization in the EU. This past quarter, we also initiated PICCOLO, a single-arm study of mirvetuximab monotherapy designed to address the increasing unmet need for an effective non-platinum option for FRα-high recurrent platinum-sensitive ovarian cancer. Beyond mirvetuximab monotherapy, we have generated encouraging data with mirvetuximab in combination with bevacizumab and carboplatin. We believe mirvetuximab has the potential to become the combination agent of choice for ovarian cancer, and we look forward to sharing our label-enabling combination strategy next quarter. As we continue to expand our team, we are very pleased to welcome Dr. Helen Thackray to our board of directors. Her deep development and regulatory expertise will be invaluable both in the near term as we look to bring mirvetuximab to market and longer term for our full portfolio. With that, I'll turn the call over to Anna to provide an update on the rest of our development pipeline. Anna? Thanks, Mark. I'll start with IMGN632, our CD123 targeting ADC in clinical development for hematological malignancies. As a reminder, IMGN632 is being evaluated as a monotherapy for patients with frontline and relapsed refractory BPDCN and in minimal residual disease positive AML, as well as in combination with azacitidine and venetoclax for patients with relapsed refractory AML. IMGN632 uses our novel indolinobenzodiazepine dimer or IGN payload, which is designed to alkylate DNA without cross-linking. Our IGNs are highly potent against leukemic blasts while demonstrating less toxicity to normal marrow progenitors. We are excited to share initial combination data from the AML cohort at ASH in December. Previously, we reported data that demonstrated the monotherapy activity and favorable tolerability of IMGN632 in heavily pretreated AML patients, including a 40% overall response rate in relapsed and refractory de novo AML patients treated at the recommended phase II dose. The combination data for IMGN632 with azacitidine and venetoclax we plan to share at ASH includes safety and anti-leukemia activity from dose escalation to guide further development of the triplet. In a separate presentation, we plan to present vignettes of frontline BPDCN patients who received IMGN632 prior to us commencing the currently enrolling pivotal cohort. Abstracts will be released next Thursday, November fourth. IMGC936, our ADAM9 targeting ADC, is advancing through phase I dose escalation in multiple solid tumor types. IMGN151, our next generation anti-folate receptor alpha ADC, is on track for IND submission by year-end. With that, I'll turn the call over to Susan to review our financials. Susan? Thanks, Anna. Starting with our results for the third quarter of 2021. We generated $9.2 million in revenue, which consisted primarily of non-cash royalty revenues and a $2.5 million anticipated partner development milestone fee. Recall, there was a reduction in non-cash royalty revenues starting in the third quarter and continuing forward due to the completion of the first tranche of payments under the 2015 transaction covering the sale of Kymriah royalties. Operating expenses were $43.4 million, comprised of $33.1 million of R&D expenses, compared with $24.7 million in the third quarter of 2020, and $10.3 million of G&A expenses compared to $10.2 million in the third quarter of 2020. We ended the third quarter with $245.8 million in cash and cash equivalents on the balance sheet. Moving to our updated financial guidance for 2021. Revenue guidance is unchanged at $65 million-$75 million. Operating expenses are now expected to be slightly lower at $190 million-$200 million, and cash and cash equivalents have increased. We expect to have between $190 million-$200 million at year-end. With the addition of approximately $43 million through our ATM facility and the sale of a pre-funded warrant to an investor during the quarter, we believe our current cash runway will be sufficient to fund operations into the fourth quarter of 2022. With that, we'll open the call for questions. Operator? Thanks. Ladies and gentlemen, to ask a question, please press star then 1. If your questions have been answered and you to lessen off the queue, press the down key. Our first question comes from John Newman with Canaccord. Your line is open. Hi, guys. Good morning. Thanks for taking my question. Congrats on all the progress. Just one question on SORAYA, which is, after the data readout, is there any need for you to meet with the agency, prior to the BLA submission in the first quarter? Thanks. Need is an interesting choice of words. What I would say is that any sponsor is very well advised to meet with the agency ahead of the filing. It's called a pre-BLA meeting. Virtually all sponsors do that. Yes, we will be talking to the agency between the top line and the filing. Okay, great. Thank you. Sure. Our next question comes from Michael Schmidt with Guggenheim. Your line is open. Michael? Yeah. Hey, guys. Sorry about that. Hey. Yeah, just two quick ones from me. The primary endpoint of the study is obviously overall response rate per investigator assessment. Can you just talk about how important the independently assessed response rate is in the approval process? That's question number one. The second question was just on the regulatory hurdle for duration of response. I think you've spoken about six months before. Some of your peers in ovarian cancer have spoken about a potential four-month DOR hurdle. Just wondering what your updated thoughts are on that. Sure, Michael. As you know, our primary endpoint is overall response rate by investigator. In the protocol, we have overall response rate by blinded independent central review as a sensitivity analysis. Consistent with prior approvals in ovarian cancer, FDA will have both data sets available to them to inform the overall benefit and risk. Regarding duration of response, for this population, there's not a lot of great data out there, but the study that has associated the 12% response rate is AURELIA. In AURELIA, the control arm of single agent chemotherapy that had a 12% response rate, that was associated with a median duration of response of 5.4 months. That being said, I can certainly understand other folks describing a meaningful duration of response of 4 months, because as you may recall, in AURELIA, these are patients with platinum-resistant disease with just one to two prior lines of therapy. It's essentially a Bev-naive population. We're going after, frankly, a higher unmet need group with including patients with three prior lines of therapy, and they have all received bevacizumab. That being said, you may recall that in our foundational 70 patients worth of data, we had a median duration of response of 7.8 months, and we believe that based on the 5.4 months from the AURELIA study, anything around 6 months or greater would certainly be clinically meaningful. Great. Thank you. Our next question comes from Andy Hsieh with William Blair. Your line is open. Great. Good morning. Thanks for taking my question, and congratulations on all the progress. Thanks. Mark, I think you mentioned something after the comments about Avastin and carboplatin combination that labeling and enabling combination strategies will be disclosed next quarter. Can you give us a little more color on that comment? Sure. As you know, we have, you know, pursued a number of early-stage studies looking at various mirvetuximab combinations and been very pleased with both the activity and the tolerability of those combinations. You know, what we've typically seen is response rates, and You know, measures of progression-free survival or duration of response that exceed the relevant benchmarks for the combination partners. For example, if you look at our early data with CARBO and MIRV, you know, what we saw was you know, response rates 70% to 80%, 80% in the FR alpha high patients, and progression-free survival of about 15 months. That contrasted nicely with other carvo doublets that have been reported, where you see response rates in the mid-50s and progression-free survival in the range of 8.5-10.5 months. With the benefit of those data along with what we've seen with MIRV-BEV, we are working through as we speak a comprehensive strategy that will include studies that will support formal label expansion with respect to these combinations. You know, some of that requires conversations with the agencies, with our investigators and so on, and we are taking the fourth quarter to work through those points with them and, you know, look forward to talking to you in the first quarter about where we come out and the studies that we're initiating. Got it. Okay. That's very clear. Thank you, Mark. I guess, you know, looking back at ESMO, I think HER2 is one of the, like, you know, conference winners in terms of compelling datasets. I'm just curious about your take on the optimizations done there, and kind of any read-through to IMGN151, the next generation asset. Andy, if you could clarify what you're thinking. You're talking about in HER2, Daiichi's HER2 ADC with a camptothecin, and you're thinking about how that's built upon the success of Kadcyla, and you're asking an analogy for how might IMGN151 build on the success of mirvetuximab. Is that what you're driving at? Yeah, that. I guess the HER2 is basically two sites of optimization, right? You know, basically the linker and the payload. I believe 151, all different components were optimized. Just curious about kind of that read-through, the clinical benefit derived from two optimizations, you know, versus, you know, theoretically three for 151. Got it. Yeah, sure. You know, we're always innovating. The innovations that we built into IMGN151 include the antibody is a biparatopic, so it binds two separate epitopes on folate receptor alpha, which we've shown leads to more internalization events and more cell killing. That translates into being able to target tumors with broader expression of FR alpha, so that we see activity, very nice activity for IMGN151 in low and medium levels of FR alpha expression in vitro and in vivo. IMGN151 is really designed to address a broad range of FR alpha-positive tumors, including essentially almost all of ovarian cancer, as well as then moving into endometrial cancer, triple negative breast and lung cancer. You're right, the linker payload has also been innovated on in terms of having a more stable linker payload that's even more stable in circulation than mirvetuximab. The payload itself is a bit more hydrophobic, a bit more potent, and has a bit more bystander killing. We're really excited to be on track to file the IND before the end of the year for IMGN151 and get that into the clinic early next year. Okay. That's very helpful. Thank you. Our next question comes from Kennen MacKay with RBC Capital Markets. Your line is open. Hi. Thanks for taking the question. I'm looking forward to the SORAYA data. Maybe with the SORAYA data really looming ahead here, just wanted to get your current perspective on sort of the bar for accelerated approval again as it relates to overall response rates as well as the confidence intervals associated with the overall response rate, rather whether that overall response rate itself is more important or non-overlapping confidence intervals there with standard of care. Secondarily, just wanted a housekeeping question here. Just wanted to see if the folate receptor alpha diagnostic would be ready to be filed alongside MIRV if SORAYA is successful in Q1 there. Thank you. Sure, Kennen. The guidance that we got from FDA is that we need to exclude 12%. What that means is the lower bound of the 95% confidence interval needs to be above 12% to be considered a statistically positive study. Certainly, you know, the larger the sample size, the narrower the confidence interval. As a reminder, we had 70 patients where we demonstrated a confirmed overall response rate of 31.4%. The lower bound of that confidence interval was 20.9%. The SORAYA study is actually a bit bigger, right? It was designed to be about 100, 105 patients. The confidence interval will be appropriate for that size study. That's in terms of statistical significance. In terms of what's clinically meaningful to physicians and patients would be a doubling of response rate from what you get expected with standard of care, single agent chemotherapy, which again is 12%. Turning to your second question, regarding the companion diagnostic, we've been working with Ventana since the inception of the mirvetuximab program, and we anticipate that the CDX will be available contemporaneously with the drug. Ventana has already filed some of the components of the PMA, so we're on track there. Our next question comes from Kelly Shi with Jefferies. Your line is open. Congrats on all the progress, and thank you for taking my questions. For the SORAYA trial, the protocol allows PARP inhibitor treatment. I wonder, like, if I estimate what percentage of the patients actually had a PARP inhibitor treatment. Also a follow-up question is, given the difference of prior treatment, Avastin and PARP inhibitor, right, compared to FORWARD I, what do you think the impact of both these agents in the background on mirvetuximab efficacy? Thank you. Over the past several years, PARPs have been adopted and incorporated into the treatment of ovarian cancer. In the FORWARD I study, which was performed at the time that the initial approvals in the treatment setting were being done and the maintenance trials were ongoing, about 10% of patients had had a prior PARP inhibitor. With each subsequent cohort that we have enrolled since then, with all of our combination studies, the percent of patients who have had a prior PARP inhibitor has increased to about 35%-40% over time, with the most recent publicly reported cohort. What we've seen is a consistent and continued efficacy of mirvetuximab regardless of prior PARP use or not. You may recall that the mechanism of action for PARP inhibitors. They interfere with the tumor cell's ability to repair DNA damage. Our drug is a tubulin-directed inhibitor, so there's no reason a priori to anticipate cross resistance between these mechanisms. Great. Thank you. As a reminder, to ask a question, please press star then one. Our next question comes from Jessica Fye with J.P. Morgan. Your line is open. Good morning, everyone. This is Daniel for Jessica Fye. Thank you for taking our question. For SORAYA, in the event that you rule out the 12% overall response rate with chemo and the analysis using the blinded independent central review, but it comes in below the doubling of chemo you've just suggested will be clinically meaningful, maybe can you talk about what that scenario would mean for approval and for the commercial opportunity for mirvetuximab? Again, we believe that a doubling of response rate would be considered clinically meaningful, and that 12% benchmark is based on investigator assessment from AURELIA. You know, we will have both datasets. FDA will review both datasets. It's really about the overall benefit risk. One is the benefit. You know, what is the response rate and what's the duration of those responses compared to available therapy? Also turning to risk. You may recall from the FORWARD I study, mirvetuximab has a very nice tolerability profile with fewer dose reductions due to drug-related adverse events and fewer discontinuations. Again, FDA will have both datasets to assess the overall benefit risk. From a study perspective, it's about ruling out a 12% overall response rate for the primary endpoint. As it relates to the commercial opportunity, you know, as Anna has said, you know, the something clinically meaningful here would be to double the response rate versus standard of care and have, you know, somewhat longer duration of response than what we see reported. I think when you look at the real-world evidence in these patients, 12% actually is, you know, an optimistic response rate, you know, as we think about additional studies that have been done here. We think with this profile, that, you know, mirvetuximab will displace single-agent chemotherapy. You know, as you think about the market opportunity here, when we look at second through fourth line platinum-resistant disease here in the U.S., each year there are roughly 22,000 patients who are available for treatment. Just under 50% of those patients get single-agent chemotherapy. That'll be our target indication, of course, with the cutoff for patients who express folate receptor alpha at high levels, which is about 40% of the patient population. We think that between SORAYA and MIRASOL, we're looking at about 4,200 patients per year. Okay. Thank you. Maybe a quick follow-up. I know it might be a little bit early, but in terms of the overall response rate that will be shown in the label, will it be based on investigator or assessment or will it be based on the BICR assessment? Investigator assessment is the primary endpoint for our study. If you look at labels for other drugs that are approved in ovarian cancer, some of them have investigator assessment, some of them have independent assessment, and some labels have both. We look forward to discussing with the FDA during label negotiations. Great. Thank you very much. Our next question comes from Jonathan Chang with SVB Leerink. Your line is open. Good morning, and thanks for taking my questions. First question, can you discuss your views regarding mirvetuximab into earlier line ovarian treatment settings? Specifically, what are your thoughts on the maintenance setting? Maintenance has certainly become a part of ovarian cancer treatment, and it's really changed the paradigm for patients now as PARP inhibitors are being adopted as well as with bevacizumab that's been around a little bit longer, both in the recurrent platinum-sensitive setting and the frontline setting. Most recently with the PAOLA-1 study, where the combination of olaparib plus bevacizumab is really you know quite helpful for patients, particularly the HRD patients. We're really excited about the potential for mirvetuximab as a maintenance option, knowing the safety profile of mirvetuximab monotherapy. We have had some patients on for well over a year, two years, even three. Also the combination for mirvetuximab plus bevacizumab. You may recall our really nice data in over 120 patients now, with very nice progression-free survival, duration of response data, and having patients on for many, many cycles. We believe that mirvetuximab absolutely has potential to be incorporated into the maintenance treatment paradigm. You know, as you heard from Mark, we look forward to sharing our label expansion strategies for combinations next quarter. Yeah, maybe just to add one point there is, I mean, there's two elements to this. The first is continuation of therapy. For example, when we think about carboplatin, you know, the first patients we enrolled got the normal 6-8 cycles of CARBO, and then they simply continued on mirvetuximab therapy. As we said, you know, we reported out small numbers, but progression-free survival about 15 months. Separately, you could imagine combining mirvetuximab with Avastin in a maintenance protocol. Having received something else as an induction therapy to generate a response and then adding mirvetuximab to that. We're working through those points as we speak and will be part of the discussion that we have next quarter. Understood. Thank you. Second question, can you provide any color on how the IMGC936 dose escalation has progressed? Should we expect data in the early part of next year? Yeah. IMGC936 is our ADAM9-targeting ADC, and it has our next-generation maytansinoid payload, DM21. ADAM9 is widely expressed across a variety of solid tumors. We're doing a dose escalation study, 3+3, in those tumors that we know express ADAM9, including triple-negative breast cancer, colorectal, lung cancer, pancreatic, and gastroesophageal. I would say that phase I dose escalation is going as anticipated, and we look forward to sharing data in 2022. I don't think I can give more timing at the moment, but we'll update it certainly as we get closer. Got it. Thanks for taking the questions. Our next question comes from RK Ramakanth with H.C. Wainwright. Your line is open. Thank you. Good morning, folks. Let me add my question on mirvetuximab as well. In terms of MIRASOL enrollment, you know, can you give us any color as to where it is at this point? MIRASOL is enrolling, and we're on track to have data Q3 next year. Okay. On 632, what sort of data expectations should we have for the combination in terms of like, you know, what sort of efficacy endpoints or safety that you would be putting out? Thank you for asking, RK. We're quite excited about ASH. IMGN632 is our CD123-targeted ADC that we are in combination with azacitidine and venetoclax, and we're looking forward to our presentation where we will share initial safety and anti-leukemia activity for the triplet. Stay tuned. Okay. Thanks for that. I think the abstracts come out, November fourth. Yes. Yes. Yes. I'm aware of that. On CADENZA, again, you know, I know you have it in your slides as to when the data is expected, but how should we think about that data on top of what we're going to see at ASH? How are you planning to build that up so that we can try to understand how this drug is working not only as a monotherapy but also as a combination therapy? IMGN632 is being studied in BPDCN, both relapse refractory BPDCN and in an enrolling pivotal frontline BPDCN cohort after we've received Breakthrough Therapy designation from FDA in the relapse refractory setting. We're also exploring IMGN632 as monotherapy in an MRD positive cohort. That cohort is open to any AML patient who is MRD positive after their prior therapy. It could be after frontline induction, or it could be later line. We look forward to sharing data at ASH for BPDCN for a handful of patients who are frontline. We've talked about them in the past. There are three frontline patients who received IMGN632 prior to us commencing the official pivotal cohort in the frontline setting. We've shared in the past that each of those patients has had a CRC, and we look forward to sharing additional details around those three patients. Thank you, Anna. Thank you very much, folks, and I'll talk to you guys soon. Thanks. Our next question comes from Joe Catanzaro with Piper Sandler. Your line is open. Hey, guys. Thanks so much for taking my question. Maybe one quick one from me, just following up on MIRASOL. Just wondering how we should think about how the SORAYA response rate and DOR translates to MIRASOL and maybe just sort of directionally where you think it would head in MIRASOL based on the SORAYA data. Thanks. SORAYA and MIRASOL are quite similar patient populations, Joe. The difference is that in MIRASOL, patients may or may not have had prior bevacizumab, whereas in SORAYA, every patient has had prior bevacizumab. However, it's the same number of lines of therapy, 1-3 prior lines of therapy. You may recall in the FORWARD I study, about half of the patients had prior bevacizumab. We anticipate a similar% of patients in MIRASOL having prior bevacizumab. Remember, in MIRASOL, the primary endpoint is progression-free survival. Of course, we will be looking at overall response rate in the MIRASOL study as well. I think that gives you a sense of the patient populations, and I think, you know, you will be able to think about how MIRASOL may play out, taking into consideration both the SORAYA data that we will share this quarter as well as the prior FORWARD I data set. Okay, thanks. That's helpful. Thanks for taking my question. Our next question comes from Boris Peaker with Cowen. Your line is open. Great. Sorry, I joined a few minutes late. If you may have addressed this, but for the AML data update later at ASH, what do you consider successful data in considering the competitive dynamics in the AML space? Yeah. CR, CRi rates are really important in AML, in relapsed refractory AML. For a combination, we think, you know, CR, CRi rates, something in the rate of 30% TO 40% would be quite clinically meaningful and would support further development. Got it. My last question is, for six-three-two, if the data achieves that threshold, what is the timeline for future development? Would you have to do a randomized study? If so, how long would something like that take? Well, given the high unmet need in relapsed refractory AML, you know, many, many combinations and single agents are used, and none of them are really outstanding. There is the potential for a single-arm study to support accelerated approval. You know, ultimately, there's also a potential for a frontline randomized study. I think it's a little early for us to really start getting into timing of what the pivotal registration trial or trials would be for the combination. We really are looking forward, however, to sharing the initial combination data for the triplet at ASH. Great. Thanks for taking my question. There are no further questions at this time. I'd like to turn the call back over to the team for any closing remarks. Great. Thanks very much. We very much appreciate you joining us this morning. Obviously, we have a big quarter yet ahead of us. Like you, we await the SORAYA data with great anticipation, and we're on track to deliver that data this quarter and then separately with IMGN632 important data at ASH. Finally, IMGN151 we expect to file the IND for that program before the end of the year. Stay tuned, and we will look forward to sharing additional data with you over the course of the quarter. Thanks. This does conclude the conference. You may now disconnect. Everyone, have a great day.