ImmunoGen, Inc. (IMGN) Q1 2022 Earnings Call Transcript

ImmunoGen, Inc. (NASDAQ: IMGN) Q1 2022 earnings call dated May. 06, 2022

Corporate Participants:

Courtney O’Konek — Senior Director of Corporate Communications

Mark Enyedy — President & Chief Executive Officer

Anna Berkenblit — Chief Medical Officer

Kristen Harrington-Smith — Chief Commercial Officer

Susan Altschuller — Chief Financial Officer

Analysts:

John Newman — Canaccord — Analyst

Michael Schmidt — Guggenheim — Analyst

Etzer Darout — BMO Capital Markets — Analyst

Boris Peaker — Cowen — Analyst

Andy Hsieh — William Blair — Analyst

Kelly Shi — Jefferies — Analyst

Jessica Fye — JPMorgan — Analyst

Joe Catanzaro — Piper Sandler — Analyst

Jonathan Chang — SVB Securities — Analyst

Presentation:

Operator

Good morning and welcome to ImmunoGen’s First Quarter 2022 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 of Corporate Communications. Please go ahead.

Courtney O’Konek — Senior Director of Corporate Communications

Good morning and thank you for joining today’s call. Earlier today, we issued a press release that includes a summary of our recent progress and first quarter 2022 financial results. This press release and a recording of this call can be found under the Investors & Media section of our website at immunogen.com. With me today are Mark Enyedy, our President and CEO; Anna Berkenblit, our Chief Medical Officer; Kristen Harrington-Smith, our Chief Commercial Officer; and Susan Altschuller, our CFO. During today’s call, we will review recent accomplishments for the business, our Q1 financial results and highlight upcoming anticipated events.

We will be making forward-looking statements based on our current expectations and beliefs. These statements are subject to risks and uncertainties and our actual results may differ materially, please consult the risks outlined in our press release issued this morning in the Risk Factors section of our most recent annual report on Form 10-K and in our other SEC filings which are available at sec.gov and immunogen.com.

And with that I’ll turn the call over to Mark.

Mark Enyedy — President & Chief Executive Officer

Good morning and thank you for joining us today. Building on the strong SORAYA data and capital raise late last year, we’ve continued to make excellent progress in 2022. Our top priority is to gain approval for mirv monotherapy in patients with folate-receptor alpha high, platinum-resistant ovarian cancer and we recently achieved 2 critical milestones to that end: the presentation of results from our positive pivotal SORAYA trial at SGO and the submission of the BLA to FDA for potential accelerated approval.

As we progress towards our goal of becoming a global fully integrated oncology company, since the start of the year, we’ve also continued enrollment in the confirmatory Phase III MIRASOL and Phase II PICCOLO studies with mirv monotherapy, expanded our commercial team and accelerated launch preparations in anticipation of a mirv approval, further accrued patients in our pivotal CADENZA study of pivek and BPDCN, initiated expansion cohorts in both relapsed and frontline AML patients combining pivek with azacitidine and venetoclax and progressed our earlier-stage programs, IMGC936 and IMGN151.

To expand on these points, starting with mirv, enrollment in our confirmatory MIRASOL trial accelerated following the release of top line results from SORAYA. This is an event-driven study, so enrollment is not the only factor in the timing of the top line analysis. Based upon a reforecast generated in conjunction with the recent prespecified interim futility analysis for MIRASOL, we now expect to reach the requisite number of PFS events in the fourth quarter of this year and report top line data from MIRASOL in early 2023.

Anna will provide more color on this and our label expansion studies in a moment. Our second pivotal program, pivek, is progressing nicely and we expect preliminary efficacy data from our pivotal CADENZA study in frontline BPDCN before year-end. In addition, patient enrollment is ongoing in our Phase Ib/II expansion cohorts evaluating pivek, azacitidine and venetoclax in both relapsed and frontline AML patients which are accruing rapidly. We expect to share data from both cohorts at ASH later this year.

Looking at the rest of our pipeline, we anticipate sharing initial data before year-end from the Phase I dose escalation trial of IMGC936, our first-in-class ADAM9 targeting ADC which we are codeveloping with MacroGenics. In addition, a manuscript describing the preclinical evaluation of IMGC936 was recently accepted for publication at Molecular Cancer Therapeutics and will soon be available online. We also made meaningful progress addressing the CMC information request from FDA regarding our Phase I study of IMGN151 and expect to initiate the clinical study by midyear. With our progress to date and meaningful catalysts ahead, we believe we are well positioned to create significant value as we move through the remainder of the year.

With that, I’ll turn the call over to Anna to provide additional color on the mirvetuximab program. Anna?

Anna Berkenblit — Chief Medical Officer

Thanks, Mark. We were thrilled to have Dr. present the results from the pivotal SORAYA trial in a plenary session at the SGO Annual Meeting in March. Since then, we have continued to engage with stakeholders across the ovarian cancer community and the enthusiasm for these data and the broader mirvetuximab program is high. As a reminder, SORAYA is a single arm Phase III study evaluating mirvetuximab in patients with folate-receptor alpha high, platinum-resistant ovarian cancer. SORAYA enrolled a heavily pretreated population of 106 patients, all of whom had received prior bevacizumab. 38% had stage IV disease, 51% had 3 prior therapies and 48% had received a prior PARP inhibitor.

Treatment options for platinum-resistant ovarian cancer consists of single-agent chemotherapy which produces low response rates and limited duration of response. The primary endpoint of SORAYA was an overall response rate of 32.4% and included 5 complete responses which rarely occur in this population. Importantly, as we updated at SGO, the median duration of response, the key secondary endpoint, was 6.9 months by investigator and the median progression-free survival, or PFS, in this heavily pretreated population was 4.3 months. These efficacy and durability data are consistent regardless of the number of prior lines of therapy or prior PARP inhibitor use.

The safety profile observed in SORAYA is consistent with that seen in the broader mirvetuximab program and is characterized by predominantly low grade, reversible ocular and GI events which were generally managed with supportive measures and dose modifications, if needed. The most common adverse events were blurred vision, keratopathy, nausea, dry eye and fatigue.

At ASCO, we look forward to presenting integrated safety data from over 450 patients treated with mirvetuximab in SORAYA, FORWARD I and our Phase I study and we plan to provide more color on SORAYA efficacy data, including the PFS curve, CA-125 response rate and impact of dose modifications. At SGO, we also disclosed that the foundational 70 SORAYA like patients all FR alpha high by PS2+, all platinum-resistant with 1 to 3 priors and all with prior bevacizumab, showed a similar median PFS with mirv as to what we saw in SORAYA.

One frequent question that arose was how these patients in the chemotherapy control arm of FORWARD I performed? Reviewing these data, the equivalent chemotherapy control population showed a median PFS of under 2.8 months. Remember that this is based on post-hoc analyses with small patient numbers, especially in the control arm of FORWARD I due to the 2:1 randomization. But nevertheless, this is consistent with bev pretreated patients representing a worse population with higher unmet need and underscores the clinical meaningfulness of the median progression-free survival of 4.3 months in SORAYA. In addition, it supports our belief that mirvetuximab will show a clinically meaningful improvement in PFS over chemotherapy with a longer median PFS in a less heavily pretreated population in MIRASOL.

Moving to MIRASOL. And as Mark mentioned, we have recently completed an interim analysis and we are pleased to report the IDMC recommended the study continue without modification. Following the disclosure of SORAYA top line results, MIRASOL enrollment increased significantly. Considering the continued acceleration of enrollment and now having assessed the PFS event rate in conjunction with the interim analysis, we are updating our MIRASOL guidance to include a projected primary completion date in the fourth quarter and top line data in early 2023.

While the timeline for MIRASOL’s top line data has been adjusted, we continue to expect potential accelerated approval for mirvetuximab monotherapy this year based on the SORAYA data. Turning to the rest of the mirvetuximab program, we’re continuing to enroll PICCOLO, our single-arm study of mirvetuximab monotherapy, in patients with folate-receptor alpha high recurrent platinum-sensitive ovarian cancer intended to support label expansion. There is an increasing need for an effective nonplatinum option in later lines of platinum-sensitive disease and we believe our Phase I antitumor activity in this population are quite promising.

Our strategy to position mirvetuximab as the combination agent of choice is also advancing. We expect to gain compendia listing for the mirvetuximab plus bevacizumab doublet in patients with folate-receptor alpha high recurrent ovarian cancer in close proximity to the initial monotherapy approval of mirvetuximab. Furthermore, work to initiate the Phase III GLORIOSA study is underway and we expect to enroll the first patient by midyear. GLORIOSA will evaluate the benefit of mirvetuximab plus bevacizumab maintenance versus bevacizumab maintenance alone in the second-line platinum-sensitive maintenance setting.

The addition of bevacizumab to a platinum doublet provides a modest improvement of PFS of just 3 to 4 months in this setting. So we are excited by mirvetuximab’s potential to improve upon this based on the data we have generated for mirvetuximab plus bevacizumab in the treatment setting. Rounding out the mirvetuximab program is trial 420. Based on promising activity observed in Phase I dose escalation for mirvetuximab plus carboplatin in recurrent platinum-sensitive disease, we plan to initiate Trial 420 this quarter to inform our path to registration in this setting. This is a single-arm Phase II study of mirvetuximab plus carboplatin, followed by mirvetuximab continuation in approximately 110 patients with folate-receptor alpha, low, medium or high platinum-sensitive ovarian cancer.

And with that, I’ll turn the call now over to Kristen to cover our commercial preparations. Kristen?

Kristen Harrington-Smith — Chief Commercial Officer

Thanks, Anna. In anticipation of bringing mirvetuximab to market later this year following potential accelerated approval by FDA, we’ve built our commercial leadership team with some key hires, including our Head of Market Access, Strategy and Operations and Sales. In addition to attracting best-in-class talent, we also have made progress on our launch imperatives. And as a reminder, those are focused on redefining expectations for positive outcomes with mirvetuximab in platinum-resistant ovarian cancer, supporting adoption of early folate-receptor alpha testing and establishing standards for in-house and centralized testing upon approval, ensuring positive physician and patient experiences through tailored education and guidance for patient management and seeking broad payer access and reimbursement to deliver a seamless patient experience.

The start of 2022 has been both intense and purposeful for the commercial team. Not only have we selected and onboarded our agency of record, we have also moved quickly to identify and address the key requirements for a successful launch while limiting potential barriers to treatment for patients. That means we are and will continue to be focused on educational efforts, supporting awareness of mirvetuximab and the importance of testing for folate receptor alpha expression and we are working in close partnership with our colleagues in medical affairs. In addition, we’ve initiated a go-to-market assessment to determine the commercial field roles necessary to drive demand, identify and prioritize relevant accounts and providers and optimize our customer-facing team.

On the market access front, we’ve initiated setup of our patient support services platform and we are actively working with our distribution channel partners to have mirvetuximab ready for shipment to customers shortly after approval. So with the focus on high-priority, high-impact initiatives and an agile experienced team in place, we believe we are well positioned for a successful launch and we look forward to bringing mirvetuximab soravtansine to patients in need.

With that, I will turn the call over to Susan to cover our financials. Susan?

Susan Altschuller — Chief Financial Officer

Thanks, Kristen. For the first quarter of 2022, we generated $38.1 million in revenue $6.4 million of which came from noncash royalty revenues. The remainder came substantially from license and milestone fees which include recognition of $21.6 million of fees previously received under the company’s collaboration agreement with Huadong Medicine and $9.2 million of a $13 million upfront fee received in the first quarter under the company’s license agreement with Lilly.

Operating expenses were $60.9 million compared with $44.6 million in the first quarter of 2021 and comprised of $44.3 million of R&D expenses compared with $34.4 million in the first quarter of 2021 and $16.6 million of selling, general and administrative expenses compared with $10.2 million in the first quarter of 2021. We ended the first quarter with $437.7 million in cash on the balance sheet. Our financial guidance for 2022 remains unchanged. We expect revenues to be between $75 million and $85 million, operating expenses between $285 million and $295 million and cash and cash equivalents at year-end between $245 million and $255 million.

Given the range in timing for potential approval of mirvetuximab, revenue guidance does not yet include potential product sales from mirvetuximab. We expect that our current cash, combined with anticipated product and collaboration revenues will fund operations comfortably into 2024.

With that, we’ll open the call for questions.

Questions and Answers:

Operator

[Operator Instructions] Our first question is from John Newman from Canaccord. Your line is open.

John Newman — Canaccord — Analyst

Hi guys, good morning, and thanks for taking my question. So you mentioned that enrollment for MIRASOL picked up following presentation of the SORAYA data this year, just wanted to confirm that the planned enrollment target for MIRASOL remains the same. You also mentioned that you anticipate compendia listing for the combination of rituximab plus Avastin, certainly after the initial mirvetuximab approval, what I’m wondering is if this were the case and doctors were to use this combination, where in the treatment paradigm do you think that combination might be used?

Anna Berkenblit — Chief Medical Officer

Thanks, John. So our enrollment target for MIRASOL remains the same at 430 patients. Enrollment did increase after we presented top line data from SORAYA late last year and so we have kept the target for MIRASOL at 430 patients. For the mirvetuximab plus Avastin combination, we anticipate receiving compendia listing in close proximity to our initial approval. And so I’ll turn it over to Kristen Harrington-Smith to discuss where that combination might be used.

Kristen Harrington-Smith — Chief Commercial Officer

Sure. So when we look at the platinum-resistant ovarian cancer market dynamics, we see that well over more than 25% of patients in any line, second, third, fourth, fourth-plus, receive a Avastin plus chemotherapy regimen or any kind of combo with bevacizumab. So we anticipate that it will be used where it’s already used in combination across those lines.

Operator

Our next question comes from Michael Schmidt with Guggenheim. Your line is open.

Michael Schmidt — Guggenheim — Analyst

Hey guys, good morning. Thanks for taking my questions. Anna, I was just wondering if you have any additional information on this MIRASOL interim analysis? I don’t know if you could share what — how many patients perhaps triggered this and what the parameters were that were assessed at that analysis? And then a second question on MIRASOL, I was just wondering around the enrollment dynamics of the trial. I’m just curious if you had overlapping trial sites with SORAYA which obviously focused on the Avastin pretreated patients that’s in SORAYA and whether perhaps that may skew enrollment early in the MIRASOL study towards Avastin-naive patients and whether that perhaps may play a role in the overall cadence of the PFS event?

Anna Berkenblit — Chief Medical Officer

Yes. Thank you, Michael. So for MIRASOL, we had a prespecified interim analysis for futility. Just like we had done in FORWARD I, it’s really to allow a dry run, if you will, from an operational perspective so that we know we’re in good shape for when we’re ready to do the final protocol-specified analysis for the primary end point. So it was triggered at the time we had 110 PFS events. And so as long as the efficacy data in terms of PFS is trending in the right direction. This study was to continue as planned and that’s exactly what IDMC recommended to us to continue the study without modification.

Turning to your second question regarding enrollment dynamics. You are correct that we do have sites that have participated both in SORAYA and are participating in MIRASOL. And so SORAYA was limited to the Avastin pretreated patients and MIRASOL allows both Avastin pretreated and Avastin naive. Given the extent of patients or rather the extended sites around the globe that are participating in MIRASOL, what I can tell you looking — tracking the demographics of the patients enrolled in MIRASOL, the percent of patients with prior Avastin is basically behaving as expected. And so we look forward to data from MIRASOL sharing the data early next year.

Michael Schmidt — Guggenheim — Analyst

Okay, great. And then, I had an unrelated follow-up just on the CADENZA study where you noted the top line data is on track for later this year in BPDCN and I was just wondering if you could remind us of the hurdle in the study and the number of patients that will be part of that filing?

Anna Berkenblit — Chief Medical Officer

Yes. So you may recall that we received breakthrough therapy designation from the data we generated in the relapsed/refractory BPDCN setting. And FDA guided us toward a study design for a pivotal frontline cohort in up to 20 patients. And the efficacy hurdle is really around what’s feasible in an ultra-rare indication and it’s to rule out a CRCRC rate of 10%. And so we do have the opportunity to stop the trial early for efficacy with less than 20 patients. And so we’re on track to have data later this year.

Michael Schmidt — Guggenheim — Analyst

Okay, super. Thanks.

Operator

Our next question comes from Etzer Darout with BMO Capital Markets. Your line is open.

Etzer Darout — BMO Capital Markets — Analyst

Hi, yes. Thanks for taking the questions, a couple for me. The first one, I guess, back to sort of the MIRASOL trial. And I guess if you could help us understand, I guess, the pushes and post the reforecast of the PFS events, does it imply any differences in sort of in underlying PFS assumptions? Or is it maybe more a factor of the recent acceleration in enrollment? And the second question, just if you could go back to the analysis you mentioned in the introductory remarks on the 2.8-month PFS for chemo and Avastin pretreated of patients and whether or not this is something that you’ve presented or would be sort of submitting to the FDA.

Anna Berkenblit — Chief Medical Officer

Thanks, Etzer. So your first question regarding the pushes and pulls involved in the reforecasting for MIRASOL. PFS is an event-driven endpoint. And — the timing of that is a factor of both the enrollment rate and the rate of having progression-free survival events. And it’s really not possible to disentangle those two. But based on how the study is performing, we have not changed our thinking regarding PFS assumptions when we designed the study. And in terms of accelerated enrollment, yes, we certainly did see an uptick in enrollment after we shared the SORAYA data. I will say it has been offset a bit based on what’s been going on in Ukraine and Russia in terms of geopolitical events and also in terms of China and the COVID surges with lockdowns in Beijing and Shanghai.

So it is multifactorial and we look forward to sharing top line data early next year. Turning to your second question regarding the 2.8-month progression-free survival on the chemotherapy control arm of FORWARD I in the SORAYA eligible subset, if you will, those are not data that we have published in a peer-reviewed manner. And certainly, the data sets are available to FDA. But really, from our perspective, it just highlights the unmet need in these patients. As we look through all of the studies that have the large studies in platinum-resistant ovarian cancer, none of them prior to SORAYA, had a uniformly pretreated population, all of whom received prior Avastin. And we know that these patients have an extremely high unmet need. The PFS for the chemotherapy patients is 2.8 months or just under 2.8 months, highlighting the unmet need.

I do need to caution folks that this is an exploratory analysis that we performed after FORWARD I read out. It’s using the PS2+ analysis. And once we rescored with the PS2+, the stratification factors were blown. And so all I would say is it’s entirely consistent from a biological perspective that chemotherapy does not work well in these patients, they need better options. And the SORAYA data have demonstrated that.

Etzer Darout — BMO Capital Markets — Analyst

Great. Thank you.

Operator

Our next question comes from Boris Peaker with Cowen. Your line is open. Boris. Your line is open, please check your unmute button.

Boris Peaker — Cowen — Analyst

Sorry, can you guys hear me?

Mark Enyedy — President & Chief Executive Officer

Can now.

Boris Peaker — Cowen — Analyst

Awesome. So I just wanted to follow up a little more on the MIRASOL interim analysis that recently completed. I’m just curious, can you comment on what was the specific stopping rules if there were maybe some kind of a PFS threshold or any kind of a hazard ratio?

Anna Berkenblit — Chief Medical Officer

Yes, Boris, the hazard ratio just needed to demonstrate PFS trending in the right direction for mirvetuximab over chemotherapy.

Boris Peaker — Cowen — Analyst

Got it. And I just want to also on the platinum-sensitive patients in the Trial 420 that you’re enrolling folate-receptor alpha low, medium and high patients, I’m just curious what’s the objective of including some of these lower expressing patients? And are you exploring some of these lower expressing patients in any other of your studies?

Anna Berkenblit — Chief Medical Officer

So early in development, Boris, when we did our combination study combining mirvetuximab with carbaplatin with Avastin, we did include a broad range of patients with folate receptor alpha expression. We now know that it’s really the high patients who benefit most from mirvetuximab monotherapy. We also know that patients with lower levels of FR alpha expression really benefit nicely from combinations, including mirvetuximab plus bevacizumab and also, in particular, mirvetuximab plus carboplatin. And we have published those data from dose escalation for mirvetuximab plus carboplatin showing really that both the mediums and the highs due extremely well with this doublet. And also we saw very nice responses in the medium. It was a small Phase I data set with just 18 patients.

And so we look forward to expanding our understanding of this doublet in a larger population in Trial 420. The hypothesis here, Boris, is that the patients with higher levels of FR alpha expression will lean a little more on the mirvetuximab activity and the patients with lower levels of FR alpha expression will lean a little more on the carboplatin activity and that the combination really should benefit a broad range of patients with FR alpha expression.

Boris Peaker — Cowen — Analyst

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

Operator

Our next question comes from Andy Hsieh with William Blair. Your line is open.

Andy Hsieh — William Blair — Analyst

Great. Thanks for taking my questions. So in terms of mirv, appreciate the 101 PFS events additional information there. I’m just wondering if you could remind us how many events are required to trigger the primary analysis of PFS out of the 430 target enrollment? And also on the regulatory front, I’m just curious in your previous discussions with the FDA, has the subject of having an AdCom ever came up during the discussion? And moving on to we’re just curious housekeeping. You mentioned about the forward dosing. Is that the 45 micrograms per kilogram that you’ll be examining? And then lastly, for CMC, I’m just curious about the process there with the FDA? Is there like a back and forth after you submit the data or should we kind of think about it as kind of an IND where after a certain period of time, it becomes active?

Anna Berkenblit — Chief Medical Officer

Great. All right, Andy. I’ll take all four. So the first 1 is that for MIRASOL, the primary endpoint is progression-free survival and the analysis will be triggered when we have 330 PFS events.

For your second question regarding an ADCOM, you may recall that we submitted the BLA for SORAYA at the end of March and we are actively engaged with FDA responding to information requests. And certainly, we expect in the coming months to understand whether or not an ADCOM would be needed, given the safety profile of our drug and the activity that we’ve seen I can’t speculate on what FDA will say but I can tell you that we will be prepared should FDA require an outcome.

Going to your third question for pivek, yes, the recommended Phase II dosing schedule in combination with azacitidine and venetoclax for pivek is 0.045 milligrams per kilogram or 45 micrograms per kilogram. And we have already opened expansion cohorts for the triplet in both relapsed/refractory AML as well as actually relapsed AML and then in the frontline cohort. And I must say, enrollment is going quite for both of those.

And to your last question, I’ll make an initial comment and turn it over to Mark. From the process to interacting with the CMC — with FDA, we’re providing data to them when we have it and then we anticipate the clinical hold will be lifted and then we’ll start enrolling patients later this year.

Mark Enyedy — President & Chief Executive Officer

Nothing to add.

Andy Hsieh — William Blair — Analyst

Great. Thanks so much.

Operator

Our next question comes from Kelly Shi with Jefferies. Your line is open.

Kelly Shi — Jefferies — Analyst

Thank you for taking my questions. First, regarding MIRASOL enrollment, could you share more color regarding the timing to complete the enrollment? And also, will the ECOG performance status influence patient outcome in both chemo and the mirv treatment arm in your view in trial? And do you think the trial has consistent ECOG split at 0 versus 1 with the previous FORWARD I MIRASOL trial? And then lastly for IMGC936, Item 986, what would be the efficacy bar to select certain tumor types for the next phase of the study? And how many inpatient data could we expect for the first data readout?

Anna Berkenblit — Chief Medical Officer

Sure. So we anticipate MIRASOL being fully enrolled this summer. Moving to your second question regarding ECOG performance status. ECOG performance status is an important predictor for how patients will do, how they’ll tolerate therapy. And we focus on enrolling patients with an ECOG performance status of zero or one. So either patients feel perfectly well or they may be a little bit tired but certainly able to work and perform all of their activities of daily living. And so both of these subsets of ECOG patients, we anticipate will be able to tolerate the therapies on both arms. And the patients that we’ve been enrolling in MIRASOL are consistent with what we expect for this population and similar to what has been seen in FORWARD I. And then lastly, your question around 936. This is our ADAM9 targeted ADC. ADAM9 is expressed in a variety of solid tumors, including pancreatic gastroesophageal lung, triple-negative breast cancer and even colorectal cancer.

And so in Phase I dose escalation, the data will guide us regarding which tumor type or tumor types we will pursue in — initially in mini expansion cohorts and then in formal expansion cohorts to support potentially accelerated approval. At this point, we’re focused on identifying the recommended dose and schedule and we look forward to sharing data this year once we have a sufficient data package that we all can interpret and share.

Kelly Shi — Jefferies — Analyst

Okay, thank you. Very helpful.

Operator

Our next question comes from Jessica Fye with JPMorgan. Your line is open.

Jessica Fye — JPMorgan — Analyst

Hey guys, good morning. Thanks for taking my questions. First, can you remind me by when you expect to hear if you’ve received priority review on the SORAYA submission? Second, can you walk through the label you hope to achieve for mirvetuximab based on the SORAYA data you submitted, particularly around it being filing with respect to prior Avastin, just given that you’re running of seems like you would answer that question, how do you handicap the probability of getting that broad label? And then lastly, with GLORIOSA expected to initiate enrollment in the middle of this year, when should we think about potentially seeing data from that trial?

Anna Berkenblit — Chief Medical Officer

Yes. So we anticipate hearing back from FDA by the end of this month regarding their acceptance of the filing and granting of priority review. Regarding the label, given the strength of the data from SORAYA, we have gone into this with a broad label. I could point out that the data for mirvetuximab monotherapy in terms of the response rate actually is a bit higher than what you see with Avastin plus chemo in a less heavily pretreated Avastin naive population. And so we’re really excited about these data and we know that mirvetuximab, based on the impressive activity in this heavily pretreated bev pretreated population, it’s going to look even better in a bev-naive population. So that is why we have gone in with the broad label. I would be hesitant to put any odds on how this would go.

And then thirdly, in terms of GLORIOSA, we’re really, really excited about this study and we look forward to getting it up and running midyear. I think it’s a little bit early, Jess, to share when we think we’ll have data from this study. But once we are up and running, we’ve got sites activated and we get a sense of how things are going, then of course, we will update our guidance.

Operator

[Operator Instructions] Our next question comes from Joe Catanzaro with Piper Sandler. Your line is open.

Joe Catanzaro — Piper Sandler — Analyst

Hey guys, thanks for taking my question. So first one, on your last call back in February, I think you said you were right on track from MIRASOL 3Q readout despite enrollment having not been completed because the enrollment dynamics were maybe more evenly distributed than FORWARD I. So I just want to understand a little better why now enrollment pace is having an impact on time lines? And then I have a follow-up.

Anna Berkenblit — Chief Medical Officer

Yes, sure. Well, you may recall, February was really before we understood the extent of the geopolitical events Ukraine and Russia. And it was also prior to the surge in COVID resulting in lockdowns in Beijing and Shanghai. And all 3 of those countries we had anticipated they would enroll a portion of the trial. And so that, unfortunately, is not quite handing out as we had anticipated. So that’s one of the drivers that is more clear now than it was in February. But the other driver is that we now have the data from the interim analysis that allowed us to reproject the event rate. So it’s really multifactorial.

Joe Catanzaro — Piper Sandler — Analyst

Okay. That’s helpful. And I guess understanding that it’s multifactorial, if I could just add, if we consider mirv’s experience in SORAYA, it seemed to behave pretty much exactly how you guys expected it to based on FORWARD I and other prior data. So is there any reason why MIRASOL could, in any way, be different from SORAYA and mirv maybe, in fact, could be outperforming your expectations? I know that’s pure speculation but wondering if you have any thoughts there?

Anna Berkenblit — Chief Medical Officer

Agree with you that’s pure speculation. And I think we’re really excited to see the data from MIRASOL because that’s certainly a possibility.

Joe Catanzaro — Piper Sandler — Analyst

Okay, great. Thanks for taking my questions.

Operator

Our next question comes from Jonathan Chang with SVB Securities. Your line is open.

Jonathan Chang — SVB Securities — Analyst

Hi guys, thanks for taking my questions. First question, what impact, if any, would you anticipate prior PARP use would have on the chemo arm performance in MIRASOL?

Anna Berkenblit — Chief Medical Officer

Jonathan, thank you for that question. The reason that you’re asking it is that was an outstanding question for mirvetuximab that we have really solidly answered with the SORAYA data set showing that mirvetuximab has very nice activity regardless of prior PARP use or not. Your point is that in the MIRASOL study, there will be a higher percentage of patients with prior PARP inhibitor than there were in FORWARD I and how is that going to impact chemotherapy. I have speculated myself that of the 3 chemotherapies, weekly paclitaxel, topotecan and Doxil prior PARP inhibitors may decrease the activity seen with patients randomized to — or assigned to the Doxil arm. And the reason I say that is Doxil like carboplatin is a DNA damaging agent, PARP inhibitors interfere with repair of DNA damage. I don’t have any data to support that. But I think mechanistically, there is the potential for the oil stratum to perform worse.

The other little data kernel, I would say, is one of the early randomized studies of a PARP inhibitor head-to-head against chemotherapy was versus Doxil and that study was negative. But this is me just speculating. I certainly don’t think prior PARP inhibitor is going to increase activity for chemotherapy. So I think either the chemotherapy control arm will do as anticipated or potentially worse.

Jonathan Chang — SVB Securities — Analyst

Got it. And just second question, ahead of the pivekimab combination data at ASH, what do you see as the appropriate benchmarks for success in frontline and relapsed/refractory AML?

Anna Berkenblit — Chief Medical Officer

So in frontline AML, the bar admittedly is high. And I think the VEN+AZA doublet has set the bar there. And we’re also tracking closely the Magrolimab triplet data. So I think those are the bars that we’re looking at. In the relapsed setting, it’s a little less clear, especially in the post VEN setting where nothing else works. But we would be thinking that a CR, CRI rate of 40% in the relapsed/refractory setting would really be something exciting that could translate into a meaningful benefit for patients.

Jonathan Chang — SVB Securities — Analyst

Got it. Thanks for taking the questions.

Operator

Our next question is a follow-up from John Newman with Canaccord. Your line is open.

John Newman — Canaccord — Analyst

Hi guys, thanks a lot for fitting me in with the follow-up. So I think investors overall sometimes are skeptical of retrospective analyses which is probably rightly so. But I just wondered if you could comment on the agreement between the actual data in SORAYA and the retrospective analysis that you did ahead of that study? Because I think it may help inform interpretation of the 2.8 months PFS from the FORWARD I subset that overlap. I just — I don’t know if you have those numbers in front of you but just curious if you could talk about that? Thanks.

Anna Berkenblit — Chief Medical Officer

Yes. So I think, John, what you’re referring to is the remarkable consistency of efficacy for mirvetuximab throughout development. And so that foundational 70 patients who are SORAYA-like, we had a response rate above 30%, we had a median duration of response of 7.8 months, we had a median PFS of 4.4 months. And we basically replicated that in the SORAYA study really quite accurately. And so similarly, we anticipate that data from the FORWARD I study for the MIRASOL-like population should replicate in the MIRASOL study. I would point folks to the 2019 ESMO presentation where Dr. Moore did show the post-hoc exploratory analysis for FORWARD I looking at FR alpha high patients for mirvetuximab versus chemotherapy.

And we saw a very nice treatment effect for mirvetuximab over chemotherapy, both by investigator and by blinded independent review with a hazard ratio of around 0.6. And so we’ve designed MIRASOL to around a hazard ratio of 0.7, so more conservatively. And so we already knew that MIRASOL was derisked with a high probability of technical success. And from my perspective, given that SORAYA has replicated prior data from that — from an exploratory post-hoc analysis, I’m even more confident that MIRASOL will also replicate the results and especially knowing that prior PARP inhibitor use does not impact mirvetuximab’s activity. We remain quite confident about MIRASOL and look forward to sharing data early next year.

John Newman — Canaccord — Analyst

Okay, great. Thank you.

Operator

I would now like to hand the conference back over to the team for closing remarks.

Mark Enyedy — President & Chief Executive Officer

Great. So as we mentioned in the opening remarks, we’re off to a strong start to the year and we’re moving fast and with purpose. And so as we look ahead, we are looking forward to our first potential product launch, generating top line data from the PVAC pivotal study and advancing the remainder of our pipeline. We’re very well positioned at this point to execute on our transition to a fully integrated company and we’re excited to offer more good days to our people, our business and our patients.

So, thanks for your time today and we will look forward to seeing you all later this month at ASCO where we’ll have some additional data from our programs. Thanks.

Operator

[Operator Closing Instructions]