David Arthur
Analyst · The Benchmark
Thank you, Mark. Now let's talk a little bit about what's happening with Salarius and what we can look forward to over the next few years. As we've discussed, our goal is to maximize the potential of seclidemstat, bring hope to patients around the world battling cancers caused by dysregulated gene expression and maximize investor return. As we look out over the remainder of 2020 and 2021 and beyond, we expect to not only advance our current clinical programs for seclidemstat in Ewing sarcoma, including Ewing's-related sarcomas and advanced solid tumors but also explore other market opportunities where we believe the seclidemstat could have a significant impact with patients fighting rare pediatric and other cancers. Both our Ewing sarcoma and advanced solid tumor clinical trials have continued enrollment during the COVID-19 outbreak, with all 9 clinical trial sites actively recruiting patients. Both studies remain a high priority at these sites. To review, both trials are designed as open-label dose-finding studies with primary objectives to characterize the pharmakinetics, characterize the safety profile and establish the maximum tolerated dose of seclidemstat. A secondary objective is to assess preliminary antitumor activity. Now, the Ewing sarcoma clinical trial and the advanced solid tumor trial are continuing dose escalation and thus far, early data from both trials suggest that plasma drug levels or the concentration of seclidemstat in a patient's plasma continue to increase in a dose proportional manner with no evidence of a plateau in exposure levels. This is important news as Salarius is now seeing plasma drug levels in patients at or above the levels where pharmacological activity was noted during preclinical studies. Following completion of dose escalation and determination of the maximum tolerated dose, which we hope to complete later this year, we plan to again dose expansion in not only patients with Ewing sarcoma, but also in patients with Ewing's-related sarcomas. On July 29, we announced that a refractory Ewing sarcoma patient who had failed previous standard-of-care therapy and was treated with single-agent seclidemstat therapy for 6 months, demonstrated a reduction in prospectively defined target lesions. Target lesions generally represent a patient's largest measurable tumors. However, and unfortunately, at 8 weeks, an increase in nontarget lesions resulted in an overall patient classification of progressive disease as designed -- as defined by the Response Evaluation Criteria in Solid Tumors or RECIST. Now this is important. We believe that clinical observations, including this prospectively defined and measured reduction in target lesions by single-agent seclidemstat treatment demonstrates preliminary drug activity. Salarius also believes this demonstration of drug activity, coupled with preclinical data supports the clinical research of seclidemstat as a potential treatment for Ewing-related sarcomas. This is why we made the decision to expand our current clinical program to include patients with Ewing-related sarcomas. We believe Ewing-related sarcomas represent an opportunity to increase the number of patients that can potentially be treated by seclidemstat and also benefit from seclidemstat therapy. Once maximum tolerated dose is established, the Ewing sarcoma trial will enter a dose expansion phase that will enroll up to 20 Ewing sarcoma patients and under the planned amendment to the trial protocol, a second cohort of the expansion phase will enroll up to 30 additional patients with either myxoid liposarcoma, desmoplastic small round cell tumors or other cancers that share the FET, family gene rearrangements, all of which are known as Ewing-related sarcomas. Expanding the ongoing Ewing trial from 20 patients to 50 patients, in the expansion phase to include patients with Ewing's-related sarcomas offers the potential, as I mentioned earlier, to develop seclidemstat for an even broader patient population. We believe this trial expansion is good for patients, and we also believe it's good for investors. We expect to initiate the expansion of Ewing sarcoma trial, including Ewing-related sarcomas in the first half of 2021, with early data disclosures from both cohorts in the second half of 2021. Now in addition to the ongoing clinical trial in advanced solid tumors provides an opportunity to explore the potential of seclidemstat in treating cancers with mutations in other epigenetic enzymes or mutations in epigenetic complexes that may have an increased sensitivity to LSD1 treatment or antiproliferative and/or immunomodulatory effects. These mutations in methyl transferase or acetyltransferase enzymes and mutations in the SWI/SNF complex occur in roughly 20% of solid tumor patients. By using commercially available genetic screens, we believe we can potentially identify and potentially enrich our advanced solid tumor expansion cohort with patients that harbor these sensitizing mutations. This type of mutational profiling is becoming more common and could represent a significant opportunity for Salarius. Further, we are exploring the use of seclidemstat in combination with checkpoint inhibitors, a type of immunotherapy designed to unleash an immune attack on cancer cells. Now while checkpoint inhibitors are a remarkable advancement in the treatment of cancer, they do not work in all cancer patients. In addition, among patients who do not -- who do show an initial response to checkpoint inhibitors, some patients can become refractory to these checkpoint inhibitors and experience a return of the disease. Now in July of this year, researchers at the Translational Genomics Research Institute in Arizona published a paper in a peer-reviewed scientific journal Plus 1. This paper represented in vitro studies, investigating the ability of seclidemstat to promote antitumor immunity and T effector cell infiltration in 2 types of ovarian cancer that both carry a specific mutation. These 2 types of cancers were small cell carcinoma of the ovary hypercalcemic type and ovarian clear cell carcinoma. In simple terms, these studies demonstrated that seclidemstat may turn cold tumors concealed from the patient's immune system into hot tumors that the immune system is able to identify. These tumors could then respond to checkpoint inhibitor treatment. We believe this is a significant potential opportunity, and we are considering clinical trials that combine seclidemstat with a checkpoint inhibitor. Another exciting area that we are exploring for seclidemstat's potential to treat hematological cancers. Other LSD1 inhibitors have clinically validated hematological or blood cancers as attractive indications for LSD1 inhibition. However, we believe that seclidemstat's differentiation may allow for certain advantages when treating these types of diseases. We are considering a clinical trial studying seclidemstat in hematological malignancies. There's a lot to be excited about with seclidemstat and our development programs. In addition to the early clinical data we have already disclosed, we anticipate a number of additional potential milestones throughout the remainder of this year and into 2021, including data from our Ewing sarcoma, Ewing's-related sarcoma and advanced solid tumor trials. In all, the progress we have made since the beginning of the year and certainly, over the past 3 months is substantial. These accomplishments have, in turn, positioned Salarius for growth on a number of fronts over the next several quarters. Now joining Mark and me to address questions is Dr. Nadeem Mirza, Senior Vice President, Clinical Development; and Dr. Daniela Santiesteban, Director of Research and Business Development. With that, I will now open the call to your questions. Kelsey, would you like to take over?