Brian Sullivan
Analyst · Jefferies. Please proceed with your question
Thank you, Robert, and good afternoon, everyone. We had an eventful and productive 2022. Our primary goal for the year was to begin enrollment of our Phase 3 VIKTORIA-1 clinical trial for our lead candidate, gedatolisib. This trial is enrolling patients with advanced HR-positive HER2-negative breast cancer, whose disease progressed after treatment with a CDK4/6 inhibitor. We began '22 working with the U.S. FDA and the European Medicines Agency to finalize feedback on our clinical trial protocol. Once we receive this feedback, we finalized our protocol and then completed selection of over 200 clinical trial sites across five continents to participate in the study. These sites include some of the world's leading breast cancer institutions. After formally activating the study in the third quarter, we were very pleased to dose our first patient this past December. The dosing of the first patient in the VIKTORIA-1 clinical trial triggered the closing of a $100 million private placement and drawdown of a $20 million term loan tranche in December. Proceeds from the private placement, combined with the debt facility and the company's current cash, cash equivalents and marketable securities are expected to be sufficient to fund Celcuity's current operating plan through 2025. So far, we are very encouraged by the activity at our VIKTORIA-1 trial sites. We remain on track with our prior guidance and continue to expect data for the PIK3CA non-mutated patient subgroup to be available in the second half of '24, and data for the PIK3CA mutated patient subgroup to be available in the first half of '25. The scientific rationale for launching the VIKTORIA-1 study was predicated on two key factors. First, there's a significant unmet need for better second-line therapeutic options for HR-positive HER2-negative breast cancer patients who received prior CDK4/6 inhibitors. Current therapeutic options offer only modest progression-free survival benefit. And second, we reported very promising results from our Phase 1b study that evaluated gedatolisib plus palbociclib combined with either letrozole or fulvestrant for patients lacking PIK3CA mutations. Published data for approved second-line therapies indicate they only offer a median PFS of two to four months. For patients who have PIK3CA mutations to publish data for median PFS of approved therapies is approximately seven months. The clinical efficacy data we initially reported in 2021 from our Phase 1b study compares very favorably to these published results. We've since updated our data to reflect 13 months of additional follow-up, and we presented this data in a spotlight poster presentation at the 2022 San Antonio Breast Cancer Symposium in December. Updates included efficacy results broken off for patient subgroups according to PIK3CA mutation status in each of the four expansion arms. For the patients in Arm D of the Phase 1b study, those who received the Phase 3 dosing schedule of gedatolisib, the ORR or objective response rate was 60% in PIK3CA wild-type patients and the percentage of patients who are progression-free at 12 months was 49%. These results compare very favorably to published data for fulvestrant, the control drug for PIK3CA wild-type patients in our VIKTORIA-1 study. In a recent randomized study, fulvestrant reported an objective response rate of 6% and a 12-month PFS rate of 12% for fulvestrant. For the Arm D patients who had PIK3CA mutations, the objective response rate was 73%, and a 12-month PFS rate was 60%. Again, these results compare very favorably to published results for the alpelisib and fulvestrant regimen, the control for PIK3CA-mutated patients in the VIKTORIA-1 study. In two clinical trials, the objective response rate for alpelisib plus fulvestrant averaged 20% and the 12-month PFS rate averaged 25%. The comparable effective response rates in 12-month PFS rate in the PIK3CA wild-type and mutated patient subgroups is driven by, we believe, two key factors. First, the PIK3 mTOR pathway is a driver in HR-positive breast cancer regardless of whether the patient's tumor has inactivating PIK3CA mutation or not. And second, inhibiting the four class I PIK3CA mutations or isoforms, and the two mTOR complexes is required to most efficaciously address PI3K mTOR pathway activity. This is the optimal approach biologically because it avoids the cross activation of uninhibited subunits and resulting drug resistance that can occur with PI3K isoform specific or mTOR specific inhibitors. Completely blockading the pathway also enhances the potential to induce synergistic inhibition with other targeted therapies such as CDK4/6 inhibitors. Gedatolisib's differentiated mechanism of action as an equipotent PANP3KMT inhibitor. This uniquely suits we believe to address the need for more effective second-line breast cancer therapies. We believe this data and the unmet need we are seeking to address played a key role in the FDA's decision to grant Breakthrough Therapy designation in July last year to gedatolisib in combination with palbociclib and fulvestrant for the treatment of HR-positive HER2-negative advanced breast cancer. We were also very encouraged by the updated efficacy results for the 41 patients in our Phase 1b study who had not received prior treatment for advanced disease. These patients received gedatolisib combined with palbociclib and letrozole as first-line treatment. In the combined group of treatment-naive patients from escalation arm A and expansion arm A, Median PFS was 42.3 months and the objective response rate was 79%. These results compare very favorably to the median PFS of 24.5 months and 55% objective response rate reported in the PALOMA-3 study for palbociclib plus letrozole. Of note is that the median PFS and expansion RMA patients alone was not reached as of the June 22 data cutoff, -- we will present updated efficacy data for expansion RMA as well as for the combined data for the two arms with treatment-naive patients at the ESMO breast cancer meeting in May. These results provide another demonstration of the intrinsic role the PI3K/mTOR pathway plays as a disease driver in advanced HR positive HER2-negative breast cancer. The data also highlights the potential opportunity to develop gedatolisib as a first-line treatment option. While a randomized first-line study evaluating gedatolisib combined with palbociclib plus letrozole is not practical for us to pursue at this time, this promising data certainly warrants a valuation in the future. Another important goal for us in 2022 was to begin evaluating and prioritizing new potential indications for gedatolisib. This evaluation includes assessment of previous trials for other PI3K and mTOR inhibitors. We view of other pathways linked to the PI3K/mTOR pathway, and conducted nonclinical studies to characterize the activity of gedatolisib in other PI3K AKT mTOR inhibitors in different tumor types. A significant body of literature has characterized the crosstalk and reciprocal feedback loops between hormonal pathway signaling and the PI3K 8K mTOR signaling cascade in multiple tumor types. This interaction plays an essential role in disease recurrence and progression in prostate and gynecological cancers in addition to breast cancer. As has been demonstrated in breast cancer, co-targeting the hormonal and PI3K AKT mTOR pathways, is a promising treatment strategy, but the approach is confounded by the feedback and feed forward loops between PI3K isoforms, AKT and mTOR that cross activate uninhibited subunits. This literature review as well as considerations of the unmet needs in various tumor types, led us to focus our initial nonclinical research studies on prostate and gynecological cancers. We presented the results -- first results from our studies, which focused on prostate cancer in February '23 at the American Society of Clinical Oncology Genitourinary Cancer Symposium. We've previously discussed how most PI3K/mTOR inhibitors selectively spare or weekly inhibit one or more key PI3K/mTOR pathway components and how this can enable drug resistance depending on the mutation status of a patient's tumor. In prostate cancer, the PTEN gene is linked to PI3K and it is frequently muted. Inhibitors that only target a single PI3K/mTOR component or AKT have demonstrated limited clinical efficacy in PTEN deficient prostate cancer and no efficacy in PTEN wild-type tumors. As has been found with breast cancer, this suggests that more comprehensive inhibition of the PI3K/mTOR pathway may be required. With this positive gedatolisib as a pan-PI3K/mTOR inhibitor would be infected in both PTEN wild-type and PTEN-deficient prostate cancer models. To assess this hypothesis, we evaluated a panel of prostate cancer cell lines with different PTEN status for their sensitivity to gedatolisib and six other inhibitors that target at least one component of the PI3K-AKT-mTOR pathway. The results from these studies were very encouraging and supportive of our hypothesis. Our assessments confirm that gedatolisib was the only inhibitor that was as potent and efficacious in PTEN wild type as PTEN-mutated prostate cancer cells. In addition, in every assessment, which included cytotoxicity, potency, cell death, DNA replication and signaling, gedatolisib exhibited superior activity relative to all of the other PI3K, AKT or mTOR inhibitors evaluated. A particular note was the contrast between gedatolisib and the AKT inhibitor, Capivasertib. Capivasertib has been evaluated in prostate cancer clinical trials, but it has only reported modest efficacy to date in PTEN-mutated tumors and no efficacy in PTEN wild-type tumors. The results from our nonclinical studies with Capivasertib are consistent with these clinical results. We found the Capivasertib was tenfold less potent in PTEN wild-type and PTEN-mutated cancer cells and generally inferior to the Pan-PSK drugs and much less active than gedatolisib. We believe these results and the contract we've got gedatolisib provide further demonstration of the importance of comprehensively rather than selectively blockading the PI3K/mTOR pathway. To assess gedatolisib in vivo activity in prostate cancer, we evaluated gedatolisib in three different prostate cancer mylenograft models. We first evaluated gedatolisib as a single agent in PTEN wild-type and PTEN-loss xenograft models that were insensitive to the androgen receptor inhibitor and dovitinib. In both models, gedatolisib induced more than 80% tumor growth inhibition, whereas dovitinib had no activity. We also evaluated a prostate cancer xeonograft model that was sensitive to dovitinib. In this model, gedatolisib induced 80% tumor growth inhibition as a single agent and 116% inhibition when it was combined with dovitinib. We will present results from our next set of clinical studies at the American Association for Cancer Research Annual Meeting, which is being held in Orlando, Florida from April 14 through the 19. These studies evaluated a panel of gynecological cell line models, which gedatolisib in several other PI3K-AKT-mTOR inhibitors. An abstract summarizing this data was published last week. Consistent with our findings in prostate cancer, gedatolisib exhibited superior activity relative to all of the other PI3K-AKT-mTOR inhibitors evaluate. Based on the results from these internal non-clinical studies and on gedatolisib's highly differentiated mechanism of action and PK/PD profile, we think there was a significant opportunity for us to develop gedatolisib in these tumor types. We will provide an update on our clinical development priorities later this year. Now I would like to shift our discussion to the diagnostics side of our business at centers on CELsignia, Celcuity's third-generation diagnostic platform. As you may recall, the enrollment in the FACT-1 and FACT-2 trials that are evaluating early-stage breast cancer patients selected using our CELsignia HER2 signaling diagnostic were impacted by COVID-19-related delays during -- up through early 2022. These trials are now enrolling patients with early-stage breast cancer whose HER2 pathway is hyperactive as detected with our CELsignia test. Our goal is to provide CELsignia test as a companion diagnostic, so that pharmaceutical companies can expand the number of patients eligible to receive their targeted therapy. We expect to announce interim results from these studies in the second half of 2023. With that, I will now turn our call over to Vicky Hahne, our CFO, to review our financial results.