Brian Sullivan
Analyst · Craig-Hallum Capital Group
Thank you, Robert. Good afternoon, everyone, and thank you for joining us today. As always, we appreciate your continued support of Celcuity.
On this call, we'll update you on our first quarter results and other business activities, focusing in particular on our strategic licensing agreement with Pfizer to develop and commercialize gedatolisib, recently reported encouraging clinical trial data for gedatolisib and an update on our clinical trial collaborations. Vicky will follow up my comments with a discussion of our financial results, and then we'll open up the line for questions.
We have had a few busy months recently. We entered into a worldwide exclusive license agreement with Pfizer to develop and commercialize gedatolisib, a first-in-class PI3K/mTOR inhibitor. We raised approximately $43 million in equity and debt. We signed clinical trial collaborations with Novartis, Pfizer and Puma. And we presented compelling clinical and nonclinical data for gedatolisib.
Obtaining the exclusive license for gedatolisib from Pfizer is a transformational strategic step for Celcuity, taking on the responsibility for the clinical development of a targeted therapy, builds off the research we've conducted over the past few years using our CELsignia platform. Our unique ability to assess the dynamic activity of signaling pathways in live patient tumor cells gives us proprietary insights into cancer drivers not available from molecular assessments.
Our research to identify various breast cancer disease mechanisms led us to focus on one of the most complex pathways linked to breast cancer, PI3K/mTOR. Our findings reveal that many breast cancer tumors have dysregulated PI3K pathways despite lacking PI3K-alpha mutations. Our research also found evidence of the importance of inhibiting all Class I PI3K isoforms in patients with PI3K-alpha mutations.
We subsequently evaluated various PI3K inhibitors using our CELsignia platform in live patient tumor cells and found that gedatolisib's unique mechanism of action was potentially ideally suited to inhibit PI3K/mTOR-involved signaling. Ultimately, our internal research findings and the clinical data Pfizer generated in a trial evaluating patients with ER-positive HER2-negative metastatic breast cancer, motivated us to in-license gedatolisib.
Under the terms of the licensing agreement, Pfizer granted Celcuity an exclusive worldwide license to develop and commercialize gedatolisib. Celcuity paid a license fee of $5 million cash and $5 million of Celcuity's common stock as upfront payments. Pfizer is also eligible to receive up to $330 million of back-end loaded development and sales-based milestone payments and to receive additional tiered royalties on potential sales.
In early April, Celcuity also announced preliminary data for the 103 patients enrolled in the expansion portion of an ongoing Phase Ib clinical trial evaluating gedatolisib in combination with the CDK4/6 inhibitor Ibrance and an endocrine therapy. Preliminary analysis of the efficacy and safety data as of January 11, 2021, cutoff date, found that 53 of the 88 evaluable patients or 60% had an objective response, and that 66 of the 88 evaluable patients or 75% had a clinical benefit. The safety analysis found that gedatolisib was also generally well tolerated with the majority of treatment-related adverse events, or TRAEs, being Grade 1 or Grade 2. The most common Grade 3 or Grade 4 TRAEs related to gedatolisib were stomatitis and rash.
Gedatolisib was also found in the study to induce a far lower rate of Grade 3 or 4 hyperglycemia and other PI3K inhibitors that target the PI3K-alpha isoform. Amongst all patients enrolled in the Phase Ib trial, only 7% had Grade 3 or 4 hyperglycemia. This is in sharp contrast to alpelisib, a PI3K-alpha targeted therapy approved for breast cancer, where 39% of patients in a Phase III trial recorded Grade 3 or Grade 4 hyperglycemia.
Our next step is to meet with the FDA to discuss our clinical development study plans for gedatolisib. Subject to the FDA’s feedback, we would then initiate a Phase II/III clinical trial evaluating gedatolisib in combination with palbociclib and an endocrine therapy in patients with ER-positive HER2-negative metastatic breast cancer in the first half of 2022.
Additionally, in April, we presented results of studies evaluating gedatolisib, inavolisib, a PI3K-alpha inhibitor, and navitoclax, a BCL inhibitor, in breast and ovarian patient tumors at the Annual Meeting of the American Association for Cancer Research. The results showed that inhibition of hyperactive PI3K/mTOR-involved signaling is 9x more effective with gedatolisib than with a PI3K-alpha inhibitor alone, such as inavolisib.
Our data also showed the synergistic cooperation between PI3K/mTOR and BCL signaling was detectable, suggesting potential patient benefit of combining gedatolisib with a BCL inhibitor. These results supported our internal evaluation of gedatolisib and further reveal the potential advantage of inhibiting all PI3K isoforms and mTOR, not just PI3K-alpha signaling when treating PI3K-involved signaling tumors.
We also made significant progress advancing development of our CELsignia companion diagnostics. CELsignia is a third-generation diagnostic platform that identifies the underlying cellular activity, dysregulated pathway signaling, in a patient's tumor so that a matching targeted therapy can be prescribed. Dysregulated signaling is too complex for molecular tests to characterize in most cases. This gives us unique opportunity to help pharmaceutical companies obtain new indications for their targeted therapies to treat the patients our CELsignia tests are uniquely able to identify.
To take the first step towards realizing this goal, we collaborate with pharmaceutical companies to evaluate the efficacy of their targeted therapies in patient populations selected by a CELsignia pathway activity test. If successful, these collaborations would represent a critical step towards obtaining a new indication that expands the market for the evaluated targeted therapies.
We continue to believe there is a significant unmet need for new therapeutic options for HER2-negative breast cancer patients. Our research suggests that many of these patients have an undiagnosed and untreated disease mechanism. We believe that CELsignia can identify the disease mechanism for roughly 25% to 35% of these patients in the targeted therapy most likely to benefit them.
Our efforts in this area are gaining momentum. And in first quarter, we entered 2 new clinical trial collaborations. In January, as we previously announced, we entered into a collaboration with the Sarah Cannon Research Institute with Pfizer for a Phase II trial. The trial will evaluate the efficacy and safety of 2 Pfizer-targeted therapies, Vizimpro, this is a pan-HER inhibitor, and Xalkori, a c-Met inhibitor, in patients with previously treated metastatic HER2-negative breast cancer selected with our CELsignia test. Patient enrollment is expected to begin in the third quarter of 2021 with interim results in the second half of 2022.
In March, we entered into a clinical trial collaboration with MD Anderson, Novartis and Puma Biotech to study a new drug regimen. The collaboration will evaluate the efficacy and safety of Novartis' targeted therapy Tabrecta and Puma's Nerlynx in patients with metastatic HER2-negative breast cancer selected by the CELsignia platform. This is our second clinical trial to treat patients diagnosed with hyperactive HER2 and c-Met signaling breast cancers with matching targeted therapies. We now have 5 clinical trial collaborations in place, and we are proud to have advanced and finalized these agreements despite the headwinds from COVID-19.
Our ongoing FACT-1 and FACT-2 II trials are evaluating anti-HER2 therapies in early-stage HER2-negative breast cancer patients. The goal of these trials is to demonstrate that breast cancer patients, identified by our CELsignia HER2 pathway activity test, obtain a higher rate of pathological complete response to new neoadjuvant anti-HER2 drug treatment than from current standard of care chemotherapies. Since patients who receive a pathological complete response to neoadjuvant drug treatment are less likely to have their cancer recur, we believe our CELsignia test can play a significant role in extending the lives of many breast cancer patients. We continue to expect interim results from our FACT-1 and FACT-2 trials in late 2021 or early 2022, barring any unforeseen additional COVID-19-related disruptions.
We're excited about these collaborations and the opportunity to work with some of the world's most prominent cancer research centers. We have additional collaboration discussions in progress, and our goal is to announce new agreements in the coming quarters.
We're also looking forward to having the opportunity to collaborate with the clinical investigators that will be conducting these new trials through our collaboration agreements. They're highly respected oncology thought leaders and researchers, and we believe their interest in collaborating with us reflects their respect for the unique potential our CELsignia test offers to identify undiagnosed disease drivers in their patients.
And finally, we recently closed 2 financings that resulted in gross proceeds of approximately $43 million. Key financing strengthened our cash position and will allow us to fund key clinical development initiatives. Vicky will describe the financing in more detail in her remarks.
So Vicky, I'd like to turn now to you to review our financial results.