Traws Pharma Inc (TRAW) 2022 Q2 法說會逐字稿

Ladies and gentlemen, thank you for standing by. Welcome to the Onconova Therapeutics Second Quarter 2022 Financial Results and Business Update Conference Call. (Operator Instructions) As a reminder, this call is being recorded today, August 11, 2022.

At this time, I'd like to turn the call over to Bruce Mackle of LifeSci Advisors. Please go ahead.

Thank you, operator, and welcome, everyone, to Onconova's Second Quarter 2022 Financial Results and Business Update Conference Call. Earlier this afternoon, Onconova issued a press release reporting its financial results and business progress. If you have not yet seen this press release, it is available in the Investors & Media section of the company's website at www.onconova.com.

Following my introduction, Onconova President and CEO, Dr. Steve Fruchtman, will provide an overview of the company's recent highlights and future outlook; followed by Chief Medical Officer, Dr. Mark Gelder, who will discuss progress across Onconova's pipeline; and lastly, Chief Operating Officer and Chief Financial Officer, Mark Guerin, will report the company's second quarter financial results. These prepared remarks will then be followed by a question-and-answer session.

Before turning the call over to Onconova's management team, I'd like to remind everyone that the statements made during this conference call will include forward-looking statements under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, which involve risks and uncertainties that can cause actual results to differ materially. Forward-looking statements speak only as of the date they are made as the underlying facts and circumstances may change. Except as required by law, Onconova disclaims any obligation to update these forward-looking statements to reflect future information, events or circumstances. For more information on forward-looking statements, please review the disclaimer in today's press release and the risk factors in the company's SEC filings.

With that, it is my pleasure to turn the call over to Steve.

Thank you, Bruce, and good afternoon to all our listeners today. This past quarter was an important period of execution for Onconova as we saw progress across our development pipeline. As we advance through the second half of the year, we remain focused internally on the advancement of our lead narazaciclib development program, which, as a reminder, consists of 2 Phase I all-comer solid tumor studies designed primarily to evaluate the safety and tolerability of our orally available, multi-targeted kinase inhibitor.

The 2 administration schemes being tested in these trials mirror those of currently approved CDK4/6 inhibitors and will identify the best recommended Phase II dose and schedule of administration of narazaciclib going forward. We have completed 4 dosing cohorts in both Phase I studies and the safety data continues to look very favorable to date, mirroring our robust preclinical data set.

Key components of this preclinical data set were featured in an abstract recently published at the American Society of Clinical Oncology Annual Meeting. These data, which Dr. Mark Gelder will discuss in greater detail, show narazaciclib potently inhibits CDK 4 and 6 and other kinases implicated in tumor growth, cancer cell survival and metastasis as well as the immunomodulatory activities.

We believe this inhibitory profile may confer narazaciclib with safety and efficacy advantages over currently available agents, highlighting its best-in-class potential. As you are aware, the CDK inhibitors are multibillion-dollar franchises to address the need for patients with hormone receptor-positive, HER2-negative metastatic breast cancer.

Looking forward for narazaciclib, we expect the continued advancement of its Phase I trials to allow for the second selection of a recommended Phase II dose, which we anticipate having before the end of this year. We continue to hone in on the indications and treatment regimens we will pursue in later-stage studies and will be informed by the results of the Phase I program throughout this process.

To better enable these efforts, we recently amended the protocol of our Phase I study to allow for the collection of pharmacodynamic data using the cutting-edge DiviTum assay. This assay is designed to measure thymidine kinase activity, a marker of cell proliferation that is believed to be predictive of CDK4 and 6 inhibitory activity or target engagement. This approach of having a biomarker to determine target engagement rather than the classic Phase I approach of observing clinical toxicity and then pulling back to a previous and lower dose for future trials is a methodology that the FDA endorses, and Dr. Gelder will give us greater details about this approach.

Though we, of course, need to finalize the specifics of our planned future trials before they are announced, I reiterate that we are interested in multiple indications for narazaciclib's potential. These include hormone receptor-positive, HER2-negative breast cancer that is refractory to the FDA-approved drugs, multiple myeloma, mantle cell lymphoma, and based on the mechanism of action of narazaciclib, other potential indications as well. This interest is drawn from both preclinical work and the pressing unmet need for improved options in these and additional indications.

Turning our attention now to rigosertib. I'll first emphasize that our strategy of utilizing investigator-sponsored trials with key opinion leaders to pursue the development of rigosertib has not changed. This enables us to dedicate our primary focus and resources to our lead narazaciclib programs. As you may recall, rigosertib can attack cancers through several different mechanisms as it has the ability to modulate, to mutate and overexpress RAS pathway, the PLK-1 pathway and the tumor immune microenvironment.

Our planned investigator-sponsored trial in checkpoint inhibitor refractory metastatic melanoma seeks to leverage rigosertib's role as an immune modulator. This trial, which will evaluate rigosertib in combination with the PD-1 checkpoint inhibitor, pembrolizumab, builds upon published preclinical data presented at prominent meetings such as the AACR and journals that came out of the work at Vanderbilt University that showed rigosertib promoting the infiltration of T cells into the tumor microenvironment.

Of course, PD-1 inhibitors work by stimulating the cancer-killing activity of T cells. Increasing the number of T cells within tumors is expected to enhance the efficacy of these exciting agents. A key goal of the melanoma trial is to demonstrate the anticancer activity of the rigosertib-pembrolizumab combination in patients showing resistance to checkpoint blockade. This is similar to another ongoing investigator-sponsored trial, which is evaluating rigosertib plus the PD-1 inhibitor, nivolumab, in KRAS-mutated nonsmall cell lung cancer.

Preliminary data from this trial strongly support the hypothesis behind the soon-to-open melanoma study. We look forward to the continued progress in both investigator-sponsored studies evaluating rigosertib with an anti-PD-1 agent and anticipate reporting additional data from the KRAS-mutated nonsmall cell lung cancer later this quarter and an abstract that has been submitted to the European Society of Medical Oncology, or ESMO.

In addition to these 2 rigosertib studies, we are also seeing extremely encouraging results in the investigator-sponsored trial evaluating rigosertib monotherapy in squamous cell carcinoma of the skin associated with the ultra-rare disease, dystrophic epidermolysis bullosa or RDEB. Initial single patient data from this trial showed a sustained complete response in this difficult-to-treat indication. And the patient is still in complete remission today and continuing on single-agent rigosertib for over 1 year.

This importantly provides clinical proof of concept for rigosertib's ability to inhibit the PLK-1 pathway, which is a crucial enzyme that is overexpressed in RDEB-associated squamous cell carcinoma and other more prevalent squamous cell cancers as well. As mentioned on our last call, this result is driving conversations with leading clinicians and scientists interested in potentially pursuing additional investigator-sponsored trials. This highlights how our collaborative strategy with rigosertib allows us to increase our avenues for value creation in a capital-efficient manner.

With that, I'll pass the call off to Dr. Mark Gelder to speak more about our clinical programs. Mark?

Thank you, Steve, and welcome again to everyone who has joined us this afternoon. As usual, I'll begin my portion of the earnings call by reviewing the status of our lead narazaciclib program and its 2 complementary Phase I dose escalation studies. These include a U.S. trial evaluating a continuous daily dosing schedule and the trial in China evaluating a 3 weeks on, 1 week off dosing schedule. Both studies are enrolling patients with advanced solid tumors.

I am pleased to report that since our last earnings call, the U.S. study has advanced from the fourth to the fifth dose escalation cohort, which is evaluating a 200-milligram oral dose of narazaciclib administered each day. We have not observed any dose-limiting toxicities or clinically meaningful cases of neutropenia in the trial to date and continue to see anticipated on-target effects of the study drug. We remain highly encouraged by these data as a dose-limiting factor and therefore, tolerability issue of both ribociclib and palbociclib. The most widely prescribed CDK4/6 inhibitors is the bone marrow toxicity or myelosuppression associated with these agents.

This necessitates an interested dosing schedule with drug given 3 out of every 4 weeks so that the bone marrow can recover. If data from our U.S. Phase I study continues to mature favorably, we would likely seek to move forward with a continuous daily dosing regimen for narazaciclib. This would clearly differentiate our therapeutic candidate and could potentially contribute to an improved efficacy profile as the 1 week off required for both palbociclib and ribociclib may permit tumor cell proliferation and therefore, tumor growth.

To better inform our development, we recently enacted a protocol amendment in the U.S. trial that will allow us to assess narazaciclib's biological activity in all cohorts moving forward. We will do this using the DiviTum assay Steve referenced earlier, which is a clinically validated blood-based test measuring the presence of thymidine kinase 1. Thymidine kinase 1, or TK1, is a well-known cell cycle regulated enzyme that is important for nucleotide metabolism during DNA synthesis.

TK1 catalyzes the conversion of thymidine to deoxythymidine monophosphate, which is then further phosphorylated to die in triphosphates prior to its incorporation into DNA. The activity of TK1 is very low or absent in resting cells and peaks in the S phase and then disappears during mitosis. Serum TK1 activity is elevated in cancer patients compared with healthy individuals and has been referred to as a liquid Ki-67.

Prior clinical trials have shown that thymidine kinase 1 or TK1 activity accurately reflects the biologic effects of CDK4/6 inhibitors. Incorporating assessments of TK1 into our Phase I program is therefore expected to provide valuable data that will enable us to move towards later-stage studies with a more thorough understanding of narazaciclib's maximal biologically effective dose and the optimal dose for achieving its maximal pharmacologic effect. This will allow us to further derisk narazaciclib's clinical development and is clearly in line with the FDA's Project Optimus initiative, which focuses on improving the dose finding and dose optimization paradigm in oncology.

In parallel with our efforts in the United States, our partner, HanX Biopharmaceuticals, continues to advance the Phase I trial of narazaciclib in China. This study is currently in its fifth dose escalation cohort which is evaluating 200 milligrams of oral narazaciclib administered each day with a 3 weeks on, 1 week off dosing schedule. As mentioned on our last earnings call, HanX is working on a protocol amendment to allow for further dose escalation in this study given the favorable safety data for the Phase I program that has been generated to date.

Continued progress in narazaciclib's Phase I trials is expected to allow for the identification of a recommended Phase II dose in the near future, perhaps before the end of the year. Once identified, we plan to utilize this dose in planned later-stage studies. As we've stated consistently in the past, these trials will include a Phase II multi-indication basket trial designed to evaluate narazaciclib alone or in combination with other anticancer agents.

To expand on a point that Steve made earlier, one indication that we intend to evaluate in our planned basket trial is CDK4/6 refractory hormone receptor-positive, HER2-negative metastatic breast cases. Those CDK4/6 inhibitors are currently approved and generate billions of dollars in annual sales in this indication. Virtually, all of these patients eventually develop resistance. This leaves a pressing unmet need we believe narazaciclib can address.

We also plan to study narazaciclib in indications where CDK4/6 inhibitors are not approved both as part of the basket trial and in additional preclinical studies. Our plans to develop narazaciclib across multiple indications are supported by a robust preclinical data set, which includes data published this past May at the American Society of Clinical Oncology or ASCO Annual Meeting. These data, which come from cell-based and in vitro assays, highlight narazaciclib's differentiated inhibitory profile.

In cell-based assays, narazaciclib demonstrated potent inhibitory activity against ARK5 and CSF1 receptor, 2 kinases that are not targeted by any of the 3 approved CDK4/6 inhibitors. We believe this finding is significant as inhibition of CSF1R leads to the activation of anticancer immunity while ARK5 plays important roles in cancer cell survival in hypoxic environments as well as metastasis. The preclinical studies featured at ASCO also compared narazaciclib to abemaciclib, which is the third approved CDK4/6 inhibitor.

Unlike palbociclib and ribociclib, abemaciclib is administered on a daily dosing schedule as neutropenia is not its primary dose-limiting toxicity. For abemaciclib, diarrhea is the primary DLT due to its affinity for the kinase GSK3 beta. Narazaciclib's inhibitory activity against GSK3 beta was filed to be approximately 29x less than that of abemaciclib, indicating that it may be, i.e., narazaciclib may be able to be administered at higher, more effective doses before causing any problem with diarrhea. As I've said before, to date, we have not seen any dose-limiting toxicities in our Phase I dose escalation trial here in the U.S. And I can tell you that in terms of adverse events, we have not seen any high-grade diarrhea.

Collectively, the result presented at ASCO suggests narazaciclib inhibitory profile may provide safety and efficacy advantages over currently approved CDK4/6 inhibitors and complement data discussed on prior earnings calls. These include mirroring data showing narazaciclib causing less bone marrow toxicity compared to palbociclib and in vitro data showing narazaciclib suppressing the growth of cancer cell lines that are resistant to palbociclib, including those lacking the retinoblastoma or RbG (sic) [Rb].

Looking ahead, we are eager to continue our work aimed at translating our promising preclinical findings to patients. We believe narazaciclib has the potential to significantly improve the therapeutic paradigm of several prevalent cancers and look forward to outlining the specifics of our future clinical plans once final.

Moving on, I'd like to briefly discuss progress in rigosertib's investigator-sponsored program. I'll focus exclusively on the ongoing lung cancer study and the upcoming melanoma study, as Steve has already provided an update on the RDEB-associated squamous cell carcinoma trial. The first study I'll mention today is the ongoing Phase I/IIa trial evaluating rigosertib plus the PD-1 inhibitor, nivolumab, in KRAS-mutated nonsmall cell lung cancer patients.

Like the melanoma study, this trial exclusively enrolls patients who have failed prior checkpoint inhibitor therapy. A preliminary readout from this study provided encouraging evidence of rigosertib's ability to overcome checkpoint inhibitor resistance, as we observed 2 partial responses and 1 stable disease in 7 evaluable patients. As the mechanism of action of rigosertib predicts, since its MOA is not dependent on any 1 specific mutation rigosertib attacks, responses we're seeing across multiple KRAS mutation variants, which differentiates rigosertib from agents exclusively focused on patients with specific KRAS mutations such as G12s. We view this preliminary data readout as highly encouraging as it supports our efforts both in this trial and the melanoma study given the similarities between the study combinations and patient populations.

Looking forward to additional data from the nonsmall cell lung cancer trial, we expect to report an updated data be an abstract submitted to the 2022 ESMO meeting, which will take place in Paris, France in September 2022. Our goal with this data readout is to see further evidence of the study doublets anticancer activity and favorable safety profile in this indication.

A key point to note about the ongoing KRAS-mutated nonsmall cell lung cancer trial is that we have yet to reach the maximum tolerated dose of rigosertib for the combination with nivolumab. Therefore, we may have the opportunity to potentially study increased doses of rigosertib combined with nivolumab in a future trial in this indication, which remains under consideration. Ultimately, a decision on this front will be based on the final data from the ongoing trial as well as conversations with experts and key opinion leaders in the field.

The second investigator-sponsored study I'll discuss is our planned Phase II trial of rigosertib plus the PD-1 checkpoint inhibitor, pembrolizumab, in patients with checkpoint blockade refractory metastatic melanoma. This trial is supported, as Steve mentioned, by the preclinical data, Ann Richmond's group, at Vanderbilt University. The trial seeks to address a key gap in metastatic melanoma's current therapeutic paradigm, as roughly half of these patients lack an effective treatment option after progressing on a checkpoint inhibitor. Primary or acquired resistance to PD-1 inhibition is known to occur in 40% to 60% of patients with metastatic melanoma, leaving many in an urgent need of a novel therapeutic approach.

Turning now to the trial's design. It will be a single arm, 2 stage study, with stage 1 expected to include approximately 10 patients. If prespecified response criteria are met, the study will be cleared to proceed to stage 2, where we'd expect to enroll an additional 19 patients. The trial's treatment regimen will consist of rigosertib, 500 milligrams orally administered twice daily on days 1 through 21 of a 28-day treatment cycle, plus the health authorities approved dose of pembrolizumab, 400 milligrams administered intravenously every 6 weeks.

The primary end point of the study is overall response rate, while key secondary end points include progression-free survival, overall survival as well as safety and tolerability assessments. We also intend to collect pre and posttreatment biomarker data to better understand rigosertib's effect on the tumor immune microenvironment. While it's too early to know when we can expect some early interim data from this study, we look forward to providing that guidance in the future as this trial progresses.

With that, I would like to introduce our Chief Operating and Chief Financial Officer, Mark Guerin, to report our second quarter financial results. Mark?

Thank you, Mark. It's my pleasure to be speaking on the call today. I'm happy to report that Onconova maintained its strong financial position over the last quarter, with cash and cash equivalents of $46.5 million as of June 30, 2022. This compares to $55.1 million as of December 31, 2021. Based on our current projections, we believe our current cash position will be sufficient to fund our ongoing clinical trials and business operations, including the pursuit of corporate development opportunities for more than 18 months. This runway is expected to enable the completion of key value-creating milestones across our pipeline.

Our research and development expenses for the second quarter of 2022 were $2 million compared to $1.9 million for the second quarter of 2021. General and administrative expenses for the second quarter of 2022 were $2.1 million compared with $2.9 million for the second quarter of 2021. We reported a net loss for the second quarter of 2022 of $4 million or $0.19 per share on 20.9 million weighted average shares outstanding. This compared with the net loss for the second quarter of 2021 of $4.2 million or $0.27 per share on 15.8 million weighted average shares outstanding.

With my financial review complete, I will now hand the call off to Steve to summarize our anticipated milestones before transitioning to question-and-answer.

Thank you, Mark. Before running through our upcoming milestones, I'd like to congratulate both Mark and our Head of Corporate Development, Dr. Adar Makovski Silverstein, on their recent and very well deserved promotions. They each have transitioned into their expanded roles seamlessly, and I look forward to our continued working together.

Turning now to anticipated milestones. We expect to identify narazaciclib's optimal Phase II dose in the second half of the year. This will inform the design of subsequent studies, including a Phase II basket trial in multiple indications and doublets. With regards to rigosertib, we plan to announce additional data from the Phase I/II KRAS-mutated nonsmall cell lung cancer trial via an abstract submitted to the upcoming ESMO meeting in September.

Alongside our narazaciclib and rigosertib programs, we continue to evaluate business-developed opportunities that could potentially expand our pipeline. Our guiding principles in this area have not changed as we are making assessments based on scientific merit and the size of the unmet need each potential candidate seeks to address.

Many companies we interact with are having problems in the current financial climate to have adequate resources to develop their own new molecular entities. Based on the financial assessment Mark shared with you, we are confident we have the required financial resources to continue our important work to develop efficacious and safe drugs for patients in need.

With that, I'd like to conclude the formal portion of today's call by thanking all those who played a role in the progress we have discussed today. This includes Onconova's employees, collaborators, investigators and most important of all, the brave clinical trial patients.

I will now open the call for questions. Operator?

(Operator Instructions) And we'll take our first question from the line of Charles Zhu with Guggenheim Securities.

Given it sounds like you're on track to identify a potential recommended Phase II dose for narazaciclib as early as end of this year, and also, it looks like you're enrolling dose cohort 5 for both of the Phase I study, should we interpret that as potentially doses cohort 6 to 7 as being a likely maximum tolerated doses?

Mark, would you like to answer that? And thank you.

So thank you, Steve. And as I said, so far, to date, through cohort 4, we have not seen any dose-limiting toxicities or DLTs. We are beginning to see some anticipated expected on-target activities. We have incorporated the DiviTum assay into the Phase I study so that we have a good PD mark.

With all of that said, I have no idea at what point we might reach our "dose-limiting toxicity" or MTD, maximal tolerated dose. What I do know is that we will continue to dose escalate until we do reach the maximum tolerated dose or a dose at which, based on the PD marker, we have clear evidence of maximal biologic effect. Whether that's this dose cohort, i.e., the fifth, whether that's the sixth or the seventh, I have no way of predicting.

But based on the "on-target activity," we are beginning to see. I think that we probably are getting reasonably close. But what exactly that will be, what dose that exactly will be and exactly when we'll get there, I can't say. I am very hopeful it's before the end of the year because we have some other studies that we would like to start moving forward, yes.

Thank you, Mark.

We'll take our next question from the line of (inaudible) with Ladenburg Thalmann.

This is (inaudible) for Ahu Demir. My question is, since Mark talked about a future Phase II basket trial, if possible, could you please give us more color on the company's plan on narazaciclib? Any plan to combine with other drugs, any other indications besides breast cancer or any specific marker to use?

Mark?

So all I can say for certain at this point is that we are putting together a panel, a slate of studies that we are very interested in moving forward with. The -- some of them are single-agent narazaciclib. Others are narazaciclib in combination with other anticancer therapies. What I can say is that in the breast cancer space, if you look at the 3 approved CDK4/6 inhibitors, most all of their approvals are in combination with an antiestrogen, whether that's an aromatase inhibitor such as letrozole or a SERD or a SERM, et cetera.

As we've said, we are clearly going to move forward in the CDK4/6 refractory hormone receptor-positive, HER2-negative metastatic breast cancer space. That will likely be in combination with an antiestrogen. The exact final decisions on the design of that trial have not yet been made, but we're 99.9% the way there. We have trial designed in mantle cell lymphoma, as we've talked about. Again, that has not been absolutely finalized. So I don't want to say much more about that. And we're looking at some other trials.

So until we get absolutely final, cemented in, written in stone trial designs with various combinations, I hate to say anything about it publicly, but that's really all I can say. Steve, you may or may not say anything more.

Well, thanks, but I think you are comprehensive. So clearly that these drugs are approved in metastatic breast cancer. As Mark mentioned, eventually, all patients who become refractory based on a mechanism of action presented at ASCO, we believe we have -- and we have cellular evidence as well, cancer cell, breast cancer that we are active in situations where palbociclib is not. So clearly, a refractory breast cancer population is a major interest.

We also have data in mantle cell, suggestive data in myeloma preclinically. So we have a number of indications we could study. And Mark mentioned some of the combinations with antiestrogens, clearly, are some of the indications. Additional may include checkpoint inhibitors, BTK inhibitors, if you think about mantle cell. So we have a number of possible studies we believe that narazaciclib can bring benefit to patients that need to show that in the Phase II bucket trials and plan to initiate as soon as we know the recommended Phase II dose.

(Operator Instructions) We'll take our next question from the line of Robert LeBoyer with NOBLE Capital Markets.

I just want a little clarification on something that you touched on a little earlier. And with the narazaciclib trial, I understand that your -- the cohorts thus far are looking very good with no dose-limiting toxicity and you're enrolling more cohorts. Is there any time frame? You kind of touched on the idea of year-end. But in terms of the next cohorts, do you have any expectation of -- or do you have more guidance on when Phase 2 would start?

So I'll take that to give Mark a breather. We can't predict when Phase 2 will start until we know the recommended Phase II dose. The reason we're suggesting we may know the recommended Phase II dose before the end of the year, even though we're not seeing, as Mark highlighted, the U.S. study, any dose-limiting toxicity, we are beginning to see engagement of our targets.

As you know, the CDK4/6 inhibitors target the most rapidly proliferating cell population in our body, and that's the bone marrow. But we are seeing some decrease in the white count in the patients treated in the current cohort with narazaciclib but not anything that approaches a serious adverse event. But since we are engaging the target in the marrow, we know we have an active drug. The white counts have begun to lower. And as we continue to dose escalate, we may see more of that, but it is hard to predict exactly when the white count or some other toxicity will be observed severe enough to call that we have reached the dose-limiting toxicity need to pull back.

But our pharmacodynamic market that Mark described in depth will also help us to determine the optimal Phase II dose. So it is hard to predict. We did try to give some guidance or we suspect perhaps by the end of this year, we will be able to know the recommended Phase II dose. And once we do that, we will rapidly move on to what we really want to do, which is open the bucket trials for the various indications that we described.

I am showing no further questions in the queue. At this time, I'd like to turn the conference back to the speakers for any closing remarks.

Thank you, operator, and thanks again to all for listening and for your insightful questions. We have enjoyed updating you on our recent progress. We continue to look forward to making even more progress. And we wish everyone a very lovely evening, and thank you again.

Ladies and gentlemen, thank you for your participation on today's conference call. This concludes today's event. You may now disconnect.