Jul 30, 2021
Operator
Good morning, and welcome to the ImmunoGen Second 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 of Corporate Communications and Investor Relations. Please go ahead.
Courtney O’Konek
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 second quarter 2021 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; and Susan Altschuller, our CFO.
During today's call, we will review key accomplishments for the business over the last 3 months, our financial results and upcoming anticipated events. During the discussion, we will use forward-looking statements, and our actual results may differ materially from such statements.
Descriptions of the risks and uncertainties associated with an investment in ImmunoGen are included in our SEC filings. And with that, I'll turn the call over to Mark.
Mark Enyedy
Thanks, Courtney. Good morning, everyone, and thank you for joining us today.
Over the past 3 months, we continued to advance our pipeline of novel ADC candidates and execute on our strategic objectives as we prepare to transition to a fully integrated oncology company with the potential for 2 innovative products on the market next year. With top line data from our pivotal SORAYA study on track for release next quarter, we've accelerated preparations for the BLA submission and commercial launch of mirvetuximab.
Given these near-term catalysts, we see this as an opportune moment to briefly review with you the U.S. market opportunity and dynamics in ovarian cancer.
Starting with growth, analyst reports and other industry data project that the ovarian cancer market in the U.S. will increase from approximately $1.6 billion today to over $3 billion in 2026 driven largely by the launch of novel targeted agents like mirvetuximab and the continued uptake of PARP inhibitors.
Looking at epidemiology, each year in the U.S., roughly 20,000 women are diagnosed with ovarian cancer and 14,000 will die from the disease. With just a 50% 5-year survival rate, ovarian is one of the deadliest cancers impacting women today.
Based on our clinical experience having tested more than 2,000 patient samples, our data suggests that approximately 40% of ovarian tumors express high levels of folate receptor alpha, which is the target patient population for mirvetuximab. Despite advances in earlier-line settings with PARP inhibitors as maintenance, the majority of ovarian cancer patients relapse and become resistant to platinum-based chemotherapy.
Treatment options for these patients are limited with poor outcomes and diminished quality of life. Against this discouraging landscape, our goal is to establish mirvetuximab as the standard of care for FR alpha high advanced ovarian cancer.
With positive data from SORAYA, we anticipate mirvetuximab's initial indication will cover second- to fourth-line patients with FR alpha high platinum-resistant ovarian cancer who've been previously treated with Avastin. We believe this represents more than 2,000 patients in the U.S.
With confirmatory data from MIRASOL, our label would expand to over 4,000 as Avastin-naive patients would also be eligible. Beyond the platinum-resistant setting, we're initiating PICCOLO, a single-arm study of mirvetuximab monotherapy in FR alpha high later-line recurrent platinum-sensitive ovarian cancer aligned with our strategy to generate data that support mirvetuximab displacing single-agent chemotherapy.
Anna will share more details on that trial in a minute. We also continue to generate highly encouraging data supporting the potential of mirvetuximab to become the combination agent of choice for ovarian cancer.
We were pleased to share final data from our mirvetuximab plus Avastin doublet in an oral presentation last month at ASCO. These data demonstrated compelling antitumor activity in patients with FR alpha high recurrent ovarian cancer regardless of platinum status.
We believe the publication of these data, together with the mirvetuximab plus Avastin cohort published in 2019, could support compendia listing in close proximity to the initial monotherapy approval for mirvetuximab ahead of formal label expansion for this combination. Given this potential, as I mentioned at the top of the call, we've accelerated our work in preparation for the BLA submission and commercial launch of mirvetuximab.
To this end, we continue to engage with the ovarian cancer medical community to educate on the robust data sets already generated with mirvetuximab and to increase awareness of folate receptor alpha as a promising biomarker for patient selection for targeted therapy. In parallel, we are gearing up to submit the BLA in the first quarter of 2022 to support potential accelerated approval in the second half of the year.
And with commercial inventory in place, we are finalizing plans for distribution. So we've got a lot going on and look forward to keeping you updated on our progress as we approach the potential launch of mirvetuximab next year.
The remainder of our innovative portfolio of ADCs is also progressing. IMGN632, our CD123-targeting ADC also has the potential to launch in 2022 in BPDCN and is also being studied in combinations in AML with data from our AML cohort expected at ASH next quarter.
IMGC936, an ADAM9-targeting ADC that we're codeveloping with MacroGenics, is advancing through dose escalation. And IMGN151, our next-generation antifolate receptor alpha ADC, is on track for an IND submission by year-end.
So with that, I'll turn the call over to Anna to provide some additional insight into our clinical programs and more on our medical education initiatives. Anna?
Anna Berkenblit
Thanks, Mark. Just a few more details on the final data from our FORWARD II study evaluating mirvetuximab in combination with Avastin in patients with medium and high FR alpha expressing recurrent ovarian cancer where treatment with a nonplatinum-based combination regimen is appropriate.
These data were presented during an oral session at ASCO in June. The combination demonstrated robust antitumor activity in patients with high FR alpha expression, including a confirmed overall response rate of 64%, a median duration of response of 11.8 months and a median progression-free survival of 10.6 months, with manageable adverse events that were consistent with the side effect profiles of each agent.
We are highly encouraged by these findings as we believe they reinforce mirvetuximab's potential to serve as a combination agent of choice in ovarian cancer and support its use in earlier lines of therapy. Additionally, a randomized Phase II investigator-sponsored study with Dr.
Philipp Harter in Germany is now underway, evaluating mirvetuximab plus carboplatin compared to standard of care in approximately 140 recurrent platinum-sensitive ovarian cancer patients. These data, along with the outcomes from the ongoing 70-patient neoadjuvant IST led by Dr.
Rebecca Arend at UAB, will further inform our path forward as we consider our label expansion options for mirvetuximab in combination with carboplatin. Turning to mirvetuximab monotherapy beyond SORAYA and MIRASOL.
This quarter, we plan to initiate patient enrollment in PICCOLO, our new single-arm study of mirvetuximab monotherapy in third-line-plus FR alpha high recurrent platinum-sensitive ovarian cancer patients with the primary end point of confirmed overall response rate and a secondary end point of duration of response. With the incorporation of PARP inhibitors as maintenance in frontline and in platinum-sensitive first relapse, more ovarian cancer patients are recurring with later-line disease that is still technically platinum-sensitive with a platinum-free interval of greater than 6 months, but these patients may not be suitable for another platinum-based therapy.
This is because of the cumulative risk of hypersensitivity reactions with repeated exposure to platinum as well as other potential toxicities related to platinum. In addition, patients who recur after their tumors have been under selective pressure from a maintenance PARP inhibitor may not be as sensitive to additional platinum as those who recur in the absence of maintenance therapy.
The PICCOLO trial is designed to address this increasing unmet need for an effective nonplatinum option in later lines of platinum-sensitive disease. As mirvetuximab moves closer to potential approval, we continue to educate the medical community on the importance of establishing folate receptor alpha as an important biomarker in ovarian cancer.
These medical education efforts include advisory boards with pathologists and oncologists, biomarker workshops and symposia at congresses and presentations at upcoming congresses. We're working with Roche Tissue Diagnostics and Roche Diagnostics Corporation to develop and commercialize the companion diagnostics for folate receptor alpha.
With the groundwork we are laying, we expect physicians to assess folate receptor alpha expression as part of their standard diagnosis and treatment decision process, following approval of mirvetuximab and the companion diagnostic. Moving to our second pivotal program.
We continue to enroll frontline and relapsed/refractory BPDCN patients in our Phase II study of IMGN632 and expect top line data in the first half of next year. Recall that 632 is also advancing in a Phase Ib/II dose-escalation study in combination with azacitidine and venetoclax in patients with relapsed/refractory AML and as a monotherapy in patients with MRD+ AML.
We look forward to presenting initial AML combination data for IMGN632 with venetoclax and azacitidine at ASH in December. As Mark mentioned, we are also excited about the advancement of IMGC936 and IMGN151 and look forward to updating you on our progress with both of these ADCs.
With that, I'll turn the call over to Susan to cover the financials. Susan?
Susan Altschuller
Thanks, Anna. Starting with our results for the second quarter of 2021.
We generated $16.9 million in revenue, which consisted primarily of noncash royalty revenues. Operating expenses were $44.3 million, comprised of $34.6 million of R&D expenses compared with $22.9 million in 2020, $9.7 million of G&A expenses compared to $9.8 million in 2020.
We ended the second quarter with $239.5 million in cash and cash equivalents on the balance sheet. Our financial guidance for 2021 remains unchanged.
We expect revenues to be between $65 million and $75 million, operating expenses between $200 million and $210 million and cash and cash equivalents at year-end to be between $140 million and $150 million. Our current cash runway continues to be sufficient to fund operations into the second half of 2022.
With that, we'll open the call for questions. Operator?
Operator
[Operator Instructions]. And our first question comes from John Newman with Canaccord.
John Newman
Just wondering if you could talk a bit more about the rationale behind the PICCOLO study. Also curious if you could talk about how that will mesh with your strategy for expanding mirvetuximab in other lines of therapy going forward after approval.
Mark Enyedy
Yes. So maybe I'll ask Anna to talk about the medical rationale and what we're seeing in terms of an increasing population of these patients and why that might be the case.
And then I can talk a little bit more about the broader strategy.
Anna Berkenblit
Yes. So we know that platinum historically has been the most active agent in ovarian cancer.
And therefore, when patients recur after platinum-based therapy, if their platinum-free interval is greater than 6 months, they typically get another line of platinum. And unfortunately, for patients, with each line of platinum, there's a law of diminishing returns, if you will, and their disease-free or progression-free survival gets shorter and shorter.
And at some point, they develop platinum-resistant disease. However, as more and more patients are being treated with PARP inhibitors in maintenance after achieving a CR or PR from platinum-based therapy, this is extending their platinum-free interval.
And so patients may now have -- still have technically platinum-sensitive recurrent disease, but their platinum-free interval, if you will, has been artificially extended by PARP inhibitor maintenance and the selective pressure that, that has been putting on the tumor. So this emerging population of patients may not be the same as patients in the olden days, if you will, who had a platinum-free interval of 6 to 12 months but their tumors saw nothing in the interim.
And so we anticipate that there will be more data out there, as more patients are becoming part of this category, that will guide further understanding what the benchmark in this population is. But what I can tell you right now is, based on anecdotal data from earlier in the mirvetuximab program where patients with recurrent platinum-sensitive disease did receive mirvetuximab monotherapy, mirvetuximab is quite active.
And so that's why we're beginning the PICCOLO study this quarter, and that will help us further understand the efficacy profile for mirvetuximab in this later-line recurrent platinum-sensitive population that is growing with an increasing unmet need.
Mark Enyedy
So John, maybe just to frame this in the broader -- in the context of the broader development plan and expected labels for the product. So our initial label comes in platinum-resistant disease.
And there, we're looking to displace single-agent chemotherapy. Single-agent chemo is about half the market in platinum-resistant disease today so the goal is to supplant that.
The remainder of the platinum-resistance space is treated with generally a range of combinations, specifically Avastin-based chemo combinations. And so the data that we published at ASCO in June really speaks to the opportunity there, and we think we've got compelling data to support a compendia listing for that indication.
When you look at the platinum-sensitive space, as Anna was talking about, patients, as their first-line therapy, are treated with carbo-pac or carbo-gem combinations often as a triplet with Avastin followed by PARP maintenance. Although the share of patients getting maintenance is -- might be smaller than one might imagine.
When you get to third-line platinum, however, or third-line therapy, what you see is only about 30% of patients are receiving platinum-based chemo. And so there's a big gap, the remainder of that population that we could target either with the mirv-bev combo and again, some of the data we had at ASCO, we had a 69% response rate with the mirv-bev combo in platinum-sensitive patients.
But this is really a gap where we think a monotherapy could fit in. The data, in terms of patient numbers, is a little sketchy in terms of third-line platinum-sensitive.
Our best estimate, based on DRG and some physician surveys, is there are about 2,000 patients in third-line. And as I said, about 30% of those patients get a platinum-based chemo regimen.
So that leaves us the remainder of that population to go after.
Operator
Our next question comes from Michael Schmidt with Guggenheim Securities.
Yige Guo
This is Yige on for Michael. I think I have a quick one on mirvetuximab.
Do you think a retreatment with mirv is possible with some of other backbones of combo therapies? And if so, with various combo regimens currently being evaluated, how could each mirv combo regimen be sequenced?
Anna Berkenblit
Yes. So there certainly is precedent for retreatment even with nontargeted cytotoxic in ovarian cancer.
So obviously, we just talked about retreatment with platinum in a lot of detail. Retreatment with tubulin-directed inhibitors like paclitaxel actually also is beneficial in ovarian cancer.
There's very nice data showing that patients who received prior Q3-week paclitaxel may benefit from subsequent weekly paclitaxel. And as you know, the payload for mirvetuximab is a tubulin-directed inhibitor.
So there certainly is the potential for repeated treatment with mirvetuximab based on the mechanism of action of the payload. Switching to the target, we did show in our biopsy cohort several years ago now that patients who received mirvetuximab and then have a subsequent biopsy after a couple of cycles of mirvetuximab still express folate receptor alpha.
So it's not quickly down-regulated that would suggest resistance.
Operator
Our next question comes from Boris Peaker with Cowen.
Boris Peaker
Maybe one question on mirvetuximab and another on 632. On mirvetuximab, can you just comment on the PICCOLO study time frame and when we'll be getting any kind of updates from it, how it overlaps with some of the other clinical studies ongoing?
Anna Berkenblit
Yes. So PICCOLO is on track to start this quarter.
And I think it's a little too early to say, Boris. Certainly, once the trial is up and running, at future calls, we can certainly provide some guidance regarding timing.
Right now, our key focus is the SORAYA BLA and MIRASOL, and we're getting people up and running. And we look forward to the data from that study because we think it's a really increasing population with unmet need.
Boris Peaker
Got it. On 632, so can you maybe set some data expectation at ASH?
And also just want to understand from a regulatory perspective, as monotherapy in MRD+ disease, what's the FDA's view on MRD+ to MRD- conversion as the regulatory end point?
Anna Berkenblit
Yes. So at ASH, we anticipate presenting all the data that we have for the triplet of 632 with azacitidine and venetoclax.
You may recall, we started out with doublet, combining with azacitidine and with venetoclax, and then we moved into the triplet dose-escalation. So we will have, I would say, a robust data set at ASH, dose-escalating, exploring 632 with azacitidine and venetoclax that will give a good sense of the safety profile of the triplet, the tolerability of the triplet as well as the anti-leukemia activity that we're seeing at this point that supports further development in the relapsed/refractory setting and ultimately perhaps in the frontline setting.
Moving to your question regarding MRD+ to - conversion, clearly that is not yet a precedent for approval in the AML setting. There is a precedent in the ALL setting, but that was a bit different because there was a prior Phase III data with overall survival benefit for the drug where it then allowed for subsequent consideration of approval in terms of MRD conversion.
I think it's a little premature to assume that it would be an appropriate end point for FDA. I would also note that ONUREG did get their approval, that's a oral azacitidine, in a broader population in maintenance, so not just MRD+ patients.
And when you look at the subset data for ONUREG, the MRD+ subset in their study doesn't do so well. And so there is certainly, I would say, a remaining unmet need there.
Hope that clarifies, Boris.
Operator
Our next question comes from Swayampakula Ramakanth with H.C. Wainwright.
Swayampakula Ramakanth
This is RK from H.C. Wainwright.
A couple of quick questions. On the press release, you have a note saying that IMGC936 is being looked at in multiple solid tumors.
Is it possible for you to enumerate at least some of the major tumors that you're looking at?
Anna Berkenblit
Sure. So IMGC936 targets ADAM9, which is a member of the matrix metalloproteinase and disintegrin family, and it is in -- expressed highly across multiple solid tumors, including pancreatic cancer, gastroesophageal cancer, triple-negative breast cancer and lung cancer.
It's also expressed in other tumor types as well. And so we've already generated very nice preclinical data showing the distribution of expression across those solid tumors, supporting their inclusion in the Phase I dose-escalation study.
We are enrolling all comers, given the anticipated ADAM9 expression in the tumor types. We're collecting tumor tissue on all patients so that retrospectively, we can look at ADAM9 by immunohistochemistry and then we'll be well positioned to develop a companion diagnostic for patient selection should we need it.
Swayampakula Ramakanth
Just a follow-up on that. Any timing at all in terms of data?
And then also regarding 151, what work needs to be done before we can launch it into the clinic?
Anna Berkenblit
Yes. So timing for IMGC936, we're in dose escalation, and we anticipate data early next year, at which point we'll have a recommended Phase II dosing safety and a sense of the tumor types that are of greatest interest.
Moving to 151. We're on track to file the IND before the end of the year.
We're doing the last bits and bobs of what we need to from a tox perspective and a CMC perspective.
Operator
Our next question comes from Andy Hsieh with William Blair.
Andy Hsieh
Congratulations on all the progress.
Mark Enyedy
Thank you.
Andy Hsieh
So regarding the PICCOLO study that you are planning to start this quarter, I am just wondering how much enrollment optimization can you achieve with the study just given your existing network of clinical trial sites for SORAYA and MIRASOL?
Anna Berkenblit
I think the short answer is a lot given that we've studied mirvetuximab now in well over 100 sites, closer to around 200 sites throughout the globe. So we're, again, like we did with SORAYA and MIRASOL, we're picking the best of the best site who have high patient volumes and participate in clinical trials with high data quality, following GCP and have the patient population that's appropriate here.
Mark Enyedy
And experience with our drug.
Anna Berkenblit
Yes.
Andy Hsieh
Right. That's helpful.
And also maybe taking a macro view on the folate receptor ADC space, maybe Mark or Anna, perhaps you can opine on the Bristol Myers and Eisai collaboration that was announced earlier this month. And also kind of looking at the pipeline, you have 4 assets right now.
In the event of a successful SORAYA trial, how should we think about future R&D investment going forward?
Mark Enyedy
Sure. So maybe I'll let Anna tackle the competitive landscape and then we can talk about where we're going in the business.
Anna Berkenblit
Yes. So we consider the BMS-Eisai deal really validating in terms of them recognizing, as we do, that folate receptor alpha is an important target in the treatment of cancer.
What I would say is that the publicly available data for their compound, MORAb-202, are, at this point, limited to a single site in Japan. As you may recall, they have linked up their failed farletuzumab naked FR alpha antibody with eribulin, which is their cytotoxic that is approved for later-line breast cancer.
And so based on the data from dose escalation in that one site in Japan, they have certainly seen activity in tumor types that are known to express folate receptor alpha. And so certainly, I think that formed the foundation for their agreement.
They are currently in a U.S. study, open at a handful of sites, on their dose-escalating.
They don't yet have a recommended Phase II dose and schedule, but we'll follow them. And I think from our perspective, not only is it validating for FR alpha, but it makes us that much more excited to get IMGN151 in the clinic as soon as possible because we really know from our preclinical data that it's designed to address a broader population of FR alpha-positive tumors and really has the chance to really move the field even further than mirvetuximab will.
Mark Enyedy
So and Andy, in terms of the future direction for the business, so you may recall when we restructured back in 2019, we chose 4 programs to move forward. And given the progress over the last 2 years, I'd say, we chose well.
But at that time, we had programs that we shelved. And in particular, we have a new class of camptothecin payloads that have been internally developed.
And so as we look ahead and with some success in SORAYA, the objective will be to move those programs off the shelf and, in particular, pursue additional development of this camptothecin payload. We have a fair amount of inbound interest with respect to the ImmunoGen platform broadly in terms of linkers and payloads and specific interest in this new class.
In addition to that, akin to the relationship that we have with MacroGenics, we continue to have folks approach us about co-development collaborations where they've identified an antibody that they think would be a good candidate for an ADC. And so those discussions are ongoing as well.
And so we do expect, following a positive outcome in SORAYA, to begin to expand the portfolio, levering our existing technology and our ability to combine with antibodies to generate novel ADCs. So it's absolutely the direction that we're heading.
Operator
Our next question comes from Kennen MacKay with RBC Capital Markets.
Unidentified Analyst
This is Sudan Loganathan [ph] on from Kennen's team. So first, I wanted to ask kind of what the benchmark is kind of discussed amongst the physician population for the single-arm PICCOLO study for mirvetuximab as a monotherapy?
So kind of what would kind of give the confidence to the physicians to use that as a monotherapy class? And then kind of where the conviction comes from you guys on the FR alpha target for ovarian cancer and then how that could grow into a monotherapy for other indications.
And then secondly, just kind of a large-picture question just on any headwinds that you see from the COVID-19 kind of macro environment to enrollment for some of the other pipeline studies that's already been kind of determined or could there be some headwinds there going forward?
Anna Berkenblit
Yes. So the benchmark question regarding PICCOLO is an important one.
So we're targeting later-line platinum-sensitive disease, and these are patients who didn't really exist in the past or if they did at very small numbers and actually, frankly, they were mostly BRCA-mutant patients because those patients whose tumors have BRCA mutations are exquisitely sensitive to platinum and they're the ones who can get multiple lines of platinum and continue to get benefit, again, each with a diminishing return. So now that PARP maintenance is being incorporated not just for BRCA mutations but also for HRD and even in an untargeted fashion, where admittedly, the benefit is less, there are still -- there are more patients with this later-line platinum-sensitive disease.
And there are, to our knowledge, no, I would say, Level I evidence papers to support a firm benchmark. I'm very personally interested in the data that will be coming out over the next year or so that will shed light on what the appropriate benchmark is.
Guardrails-wise, the data that are out there, admittedly from older populations that are less relevant now, include response rates in second- and third-line platinum-sensitive disease for nonplatinum single agents of 10% to 12%. And in those later-line 3 to 4 priors who are platinum-sensitive and have a BRCA mutation, the response rate is about 30%.
If you look at platinum doublets in patients who've just had 1 prior line, the response rate is about 40%, 45%. So imagine it dropping with each line of therapy, and this is why we really believe there's a high unmet need for these patients.
And again, based on the anecdotal data that we have, we're quite excited about the potential for mirvetuximab in this population. That was your first question.
Your second question was other indications. So for mirvetuximab, we are supporting a couple of investigator-sponsored trials in endometrial cancer.
One is a monotherapy in high-grade serous endometrial cancer and one in combination with pembrolizumab. We have some data for mirvetuximab monotherapy in endometrial cancer already that suggests that would be an interesting additional target.
I think we're saving lung cancer and triple-negative breast cancer for IMGN151. And then your last question was regarding COVID-19 headwinds.
Yes, there are COVID-19 headwinds. I mean with the Delta variant emerging now and the recent CDC guidance around masking, it will be interesting to see, frankly, how hospitals and clinical sites may be changing their working policies.
I don't think it's going to necessarily impact patient care because patients with recurrent ovarian cancer need treatment. But I wouldn't be surprised if there are, like we've already experienced, some delays in contract turnover, IRB meetings, the paperwork aspect of clinical trials if people are working from home.
But what I'd also say is during COVID over this past year, we've gotten really good at managing through those with our contingencies.
Operator
Our next question comes from Kelly Shi with Jefferies.
Kelly Shi
I also have a question for PICCOLO trial. What drives -- at this stage, what drives this area to only include FR alpha high patients, given that you mentioned there are large unmet needs in the third-line platinum-sensitive patients and also, based on the previous experience, mirv is actually in the FR alpha intermediate patients?
Anna Berkenblit
Yes. We know, now having studied mirvetuximab in well over 800 patients, the higher the FR alpha expression, the deeper and more durable the tumor shrinkage.
So you are absolutely right that mirvetuximab is active in patients with medium FR alpha expression, which is about 20% of the population. We know from the FORWARD I study that it's probably about the same in terms of its activity with single-agent chemotherapy.
But we're really trying to move the field forward and have the potential to be the agent of choice. And we want to go where we can benefit patients the most, and that's really the 40% with high FR alpha expression.
And that's based on archival tumor tissue. It's irrespective of platinum sensitivity or resistance.
Operator
Our next question comes from Joe Catanzaro with Piper Sandler.
Joseph Catanzaro
Anna, you mentioned the Phase I experience with mirvetuximab in platinum-sensitive patients, just wondering the extent of prior PARP exposure in that population and whether there's any reason to think that extended PARP maintenance could potentially impact subsequent sensitivity to mirvetuximab. And then just with regards to cash guidance and it being sufficient into the second half of 2022, what is that inclusive of and, I guess, specifically around the potential commercial launches of both mirvetuximab and 632?
Anna Berkenblit
Yes. So the anecdotal data that we have, Joe, is, I would say, limited but quite encouraging.
And there are certainly patients, in our experience, who had a prior PARP inhibitor and have recurrent platinum-sensitive disease and do very nicely with mirvetuximab. Throughout our program, when we've looked at patients who've had a prior PARP inhibitor, whatever trial we look at, we see very nice activity for mirvetuximab.
And that's not surprising because there's no reason to believe there's a cross-resistance mechanism. PARP inhibitors interfere with the ability to repair DNA damage or a tubulin-directed agent.
And so again, prior PARP use really doesn't seem to impact the efficacy of mirv.
Susan Altschuller
Great. And on the guidance that goes into the second half of 2022, that includes spend for prelaunch prep and BLA filing, commercialization work for both mirvetuximab and 632.
We feel that we're in a strong place. We've been adding additional capital from our ATM facility.
That said, we're -- I'd focus on the year-end cash now. We're looking for ways to supplement that between now and then.
But with a positive readout, we don't think capital formation will be an issue.
Mark Enyedy
Yes. Maybe just to put a little finer point on some of what Susan was saying in terms of what we're doing from an operational perspective.
So those numbers include sales force build. It includes production of additional launch inventory for the business, buildout of the medical affairs function.
So baked into that number is a fully formed organization ready to launch the drug in the second half of the year.
Operator
Our next question comes from Jessica Fye with JPMorgan.
Daniel Wolle
This is Daniel for Jessica Fye. Maybe a question for Anna.
Targeting CD123 in AML hasn't been as effective as the antitumor benefits we've observed in BPDCN. Could you maybe frame for us what could be driving a differentiated outcome in those two settings and how 632 can be differentiated here in AML?
Anna Berkenblit
Yes. So I think what you're referring to is the activity of ELZONRIS or tagraxofusp or SL-401, which is approved for BPDCN.
It's a CD123 fusion protein with a diphtheria toxin. And BPDCN has the highest level of CD123 expression.
So if it's going to work anywhere, it's going to work there. And I think their monotherapy experience in AML was quite disappointing.
They really didn't have appreciable monotherapy activity in AML. That contrasts with our experience with IMGN632.
You may recall at ASH, we've had a couple of oral presentations now showing actually quite reasonable monotherapy activity for IMGN632 in relapsed/refractory AML with very nice CRi. It didn't quite meet our bar for a single-arm fast-to-approval strategy in the relapsed/refractory setting, but certainly highly active.
Our drug is highly active as a monotherapy in AML, and I think it's just because we have a better drug, frankly.
Operator
Our next question comes from John Newman with Canaccord.
John Newman
Perhaps a little noisy. A question for Mark and Anna, this is probably a difficult question to answer.
But there's been a lot of conversation on prior calls about the accelerated approval pathway for mirvetuximab, but given the current timing for the program, BLA submission in early 2022 and then top line data for MIRASOL, I believe, in the third quarter of 2022, isn't it reasonable to assume that the FDA will be able to get a look at the top line data for MIRASOL, which could give them more confidence in the accelerated approval based on SORAYA?
Mark Enyedy
Yes. So I think you have to deconstruct this and ask the question, what is the regulatory environment here?
And what -- and then ask the question about practical considerations that overlay that. But from a regulatory perspective, we file under Subpart E looking for accelerated approval.
The standard there is to demonstrate a substantial improvement over available therapy. The FDA gave us the benchmark in terms of overall response rate, which is the primary end point for our study, and then secondarily looking at duration of response.
And so if we meet those criteria under Subpart E with the data that we generate from SORAYA, there's no basis for the FDA to delay regulatory action on the filing. So I think that's the first point.
Yes, if MIRASOL data are available at the time of the regulatory decision and those data are positive, we think they will be positive, yes, that would certainly bolster their ability to make a decision on mirvetuximab. But again, I think the base criteria here is what are the applicable regulatory standards for accelerated approval, and we think we're going to meet those with SORAYA and that will be the basis for regulatory action.
Operator
And I'm showing no other questions in the queue. I'd like to turn the call back to Mark Enyedy for any closing remarks.
Mark Enyedy
Great. Well, thanks very much for your time today, and we look forward to keeping you updated on our progress and to fourth quarter with a SORAYA readout and also data on 632 at ASH.
Thanks very much, and have a nice weekend.
Operator
This concludes today's conference call. Thank you for participating.
You may now disconnect.