David Melnick
Analyst · Cowen & Company. Please proceed with your question
Thank you, Ankit. I'm very happy to share our pipeline updates today. Let me begin with our lead candidate tebipenem HBr and oral carbapenem for which we've reported positive Phase 3 data in September. The Phase 3 clinical trial entitled ADAPT-PO met its primary endpoint demonstrating that oral tebipenem HBr is non-inferior to IV ertapenem in the treatment of patients with complicated urinary tract infections, including acute pyelonephritis. The primary endpoint was met with an overall that is a combined clinical and microbiologic response rate of 58.8% for oral tebipenem HBr and 61.6% for intravenous ertapenem meeting the pre-specified non-inferiority margin of 12.5%. These and other ADAPT-PO data, which were presented in an oral late-breaker presentation at IDWeek last October show that both the clinical cure and microbiological eradication rates were comparable between the treatment groups at the end of treatment, at test-of-cure and at the late follow-up visits. ADAPT-PO also showed that tebipenem HBr had a compelling safety and tolerability profile, which was similar to that of intravenously administered ertapenem. Both the type and frequency of adverse events were well balanced across the treatment groups with treatment-emerging adverse events reported in 26% of patients in both treatment arms. The most commonly observed treatment emergent adverse events were diarrhea and headaches, which were of similar frequency in both arms. There were no cases of clostridium difficile infection observed in the tebipenem HBr group, which compares to three cases observed in the ertapenem arm of the study, unfortunately, no deaths were reported across the treatment arms. Now, I'd like to take a moment to reiterate an important point that we've made in the past, which is that we believe that these ADAPT-PO results mean to positions on an important advance in the treatment of patients with complicated UTI. The continued emergence of antibiotic resistance and Gram-negative bacteria has limited the utility of the currently available oral antibiotic treatment options. As Ankit mentioned, ADAPT-PO was the first trial of its kind in complicated UTI as it was a straight head-to-head comparison of orally administered tebipenem HBr versus intravenously administered ertapenem, specifically not include an IV lead-in in the tebipenem HBr arm, nor an oral step down in the IV ertapenem arm. Thanks to this robust trial design. We have generated a strong data set that we believe provides physicians with the evidence they will need to feel confident prescribing oral tebipenem instead of IV ertapenem to patients with complicated urinary tract infections. Looking forward, we continue to anticipate completing the NDA submission for tebipenem HBr in the second half of 2021. All of the supporting Phase 1 studies have now been completed and all of the clinical data that will be included in the NDA package is currently in hand. In parallel with these efforts regarding the NDA, we also continue to work with our partners to ramp up our CMC capabilities ahead of tebipenem's expected launch in 2022. It's been gratifying to see how much a strong external interest there has been in the clinical utility of tebipenem HBr as an alternative to intravenous antibiotic therapy. Our medical affairs strategy includes the initiation of several investigator sponsored studies that should increase our understanding of the function of tebipenem HBr in different tissues. One study will assess the treatment of patients with Gram-negative ESBL bacteremia comparing early transition to oral antibiotic therapy with tebipenem HBr to continued intravenous carbapenem therapy. We also expect to report data from the Phase 1 bronchoalveolar lavage trial assessing the long penetration of tebipenem HBr in the second half of this year. This important trial, which commenced in December, is designed to determine the pharmacokinetics of tebipenem in lung tissue. Funded by BARDA, this study has a strong clinical rationale as a powdered form of tebipenem is currently approved in Japan in several respiratory indications, including the treatment of children with pneumonia. In addition, we plan to have a presence at four infectious diseases and urology conferences this year, where we will present additional ADAPT-PO data, as well as in vitro surveillance data, assessing the activity of tebipenem HBr against other gram-negative pathogens. I'll now move on to discuss SPR720, our oral drug candidate in development for the treatment of NTM infection. As Ankit mentioned, we initiated a Phase 2a clinical trial of 720 for the treatment of NTM patients in December. Last month we announced that the FDA issued a verbal clinical hole to this trial. This came after we had notified the agency of our internal decision to pause the trial based on unexplained mortality, seen in a study of adult non-human primates in an ongoing toxicology study. I should note that the mortality did not correlate with the dose levels or duration of SPR720 drug exposure. Further these adult non-human primates are historically known to be very challenging to dose, which adds a level of complexity to the analysis. We continued to evaluate the data in conjunction with FDA to better understand the cause of mortality, mainly if it is related to the specific species of monkey, the manner of administration or if it is a drug related attack. In a recent written communication, the FDA asked for study report from the preclinical toxicology study, which we are currently working to complete. Before moving on to talk about SPR206; I'd like to reiterate a point that Ankit touched on earlier. The events observed in this non-human primate toxicology study were a departure from what we had previously observed in preclinical and clinical studies with SPR720. SPR720 has previously been assessed in a series of non-clinical GLP toxicology and safety pharmacology studies, including IND enabling 28-day and 31-day GLP toxicology studies in non-human primates and rats respectively. Even though remarkable findings observed in these completed studies, we are also currently conducting a four-month toxicology study in rats that has been uneventful. In addition, in the prior single and multiple ascending dose Phase 1 clinical trial evaluating the safety, tolerability and pharmacokinetics of early administered SPR720, no serious adverse events were reported and all human volunteers completed the trial. Based on the data we've seen to date, we continue to believe that there is a path forward for SPR720 for the treatment of NTM pulmonary disease. To better facilitate potential adjustments to the Phase 2a clinical trial protocol we have decided to discontinue the Phase 2a clinical trial at this time. I should reiterate a point that Ankit made earlier and say that discontinuing the trial is not a repeat, not indicative of any decision that we've made on the program with any drug related findings. The clinical trial was at an early stage of enrollment at the time of the whole, thus we believe maintaining the trial in the pause state would not have been of any benefit with regards to the trial and data that we could deliver. We continue to work with FDA to evaluate the findings and determine the best pathway for the continued clinical development of SPR720. Switching gears now to discuss SPR206; our next generation IV polymyxin agent that has developed as part of our potentiator platform, we continue to advance this compound with support from our partners at the department of defense and Everest Medicines. SPR206 is a potent drug candidate that has shown activity against extensively drug resistant bacterial strains including multi-drug resistant pseudomonas aeruginosa, acinetobacter baumannii and carbapenemase producing intro back Ralphs, all of which are on the world health organization priority pathogen list. The need for good medicines to fight bacterial infections in the hospital is further emphasized by the COVID-19 pandemic. In particular patients with severe COVID-19 often require intubation and mechanical ventilation rendering them vulnerable to ventilator associated bacterial pneumonia. In fact, mortality in COVID-19 is frequently associated with these secondary bacterial infections, which are in turn often caused by antibiotic resistant pathogens. We remain on track to initiate our Phase 1 bronchoalveolar lavage, clinical trial in the first half of 2021, in order to evaluate of SPR206 into the lung compartment. We were also on track to initiate a renal impairment study this year. We are advancing SPR207 into these additional crowds based on the encouraging Phase 1 data in healthy volunteers that we announced last year. In this study, healthy volunteers were given doses of SPR206 up to 300 milligrams daily for 14 consecutive days, and there were no severe or serious adverse events reported. Importantly, there was no evidence of network toxicity or clinically significant changes in laboratory tests, which clearly differentiates 206 from the earlier generation of polymyxin. I will now turn the call over to Cristina Larkin, our Chief Operating Officer, who will provide you with a review of the market opportunity for our pipeline products and detail our strategy through the potential launch of tebipenem HBr. Cristina?