Sanjay Shukla
Analyst · RBC Capital Markets. You may proceed
Thank you, Ashlee. Good afternoon, everyone, and thank you for joining us for our second quarter results conference call. We're pleased with the progress we've made in the second quarter as we advance our Phase 3 study of efzofitimod in patients with pulmonary sarcoidosis. This global pivotal study is a major milestone for aTyr in the sarcoidosis community as it is projected to be the largest interventional study for patients with sarcoidosis to date. I'm happy to report that, the studies underway with several centers initiated in the US And importantly, we remain on track to enroll a patient this quarter. As we begin, I'll summarize a few highlights since we last spoke in May. We announced plans to initiate EFZO-FIT, a global pivotal Phase 3 study to evaluate the efficacy and safety of efzofitimod in patients with pulmonary sarcoidosis. We announced fiberglass growth factor receptor 4 or FGFR4 as the target receptor for a fragment of the Alanyl-tRNA Synthetase which is also knows AARS. And we were recently very pleased to receive FDA Fast Track Designation for Efzofitimod for the treatment of Pulmonary Sarcoidosis. Since the announcement of the EFZO-FIT study in May 2022, we've rapidly executed a number of operational milestones to advance the study start. Multiple interactions with regulatory authorities in the US, EU and Japan have occurred, along with the submission of the study protocol, and clinical trial applications to regulatory authorities, APEX committees and institutional review boards. Site selection, qualification and initiation for several sites have occurred as well as an investigator meeting for US sites. It's been a highly productive period for AARS from the point of receiving our FDA green light on the design of the EFZO-FIT study just last quarter to now, and we eagerly anticipate enrolling a patient soon. I'd like to acknowledge our fantastic clinical operations team that has moved at light speed to get our pivotal trial launched so expeditiously. With that said, let's discuss our clinical program for efzofitimod in a bit more detail. As a reminder, efzofitimod is a first-in-class immunomodulator for fibrotic lung disease. Efzofitimod is a novel Fc fusion protein based on the naturally occurring splice variant of the lung-enriched tRNA synthetase HARS fragment that downregulates aberrant immune responses in inflammatory disease states. Efzofitimod has been shown preclinically to downregulate inflammatory cytokine and chemokine signaling and reduce inflammation and fibrosis. The neuropilin-2, or NRP2 receptor is upregulated on key immune cells during active inflammation and is enriched in inflamed lung tissue. Efzofitimod binds selectively to NRP2 and therefore has the potential to normalize the immune system, serving to resolve inflammation and prevent progressive fibrosis, thereby stabilizing lung function and alleviating morbidity and mortality. We're developing efzofitimod as a potential treatment for patients with interstitial lung disease, or ILD, a group of rare immune-mediated fibrotic lung disorders. Our initial ILD indication for efzofitimod is pulmonary sarcoidosis. Sarcoidosis is the most prevalent ILD and is characterized by the formation of granulomas, or clumps of immune cells, in one or more organs of the body. Sarcoidosis that affects the lungs is called pulmonary sarcoidosis and occurs in more than 90% of cases. If left untreated, persistent granulomatous inflammation can lead to irreversible scarring or fibrosis, which may lead to respiratory failure and death. We estimate that there are close to 200,000 patients with pulmonary sarcoidosis in the US, around 150,000 in major European markets and another 20,000 in Japan, up to 75% of patients require treatment for their disease. Approximately 1/2 of these will progressively – progress disease despite treatment. And around 1 in 5 of all patients will undergo -- will go on to develop lung fibrosis. Indication for treatment of sarcoidosis is two-fold: to avoid danger to an organ, or to improve quality of life. First-line treatment is typically corticosteroids, which may effectively control symptoms, but are associated with severe debilitating side effects, particularly with chronic treatment. Second and third-line treatments are antimetabolite immunosuppressants, such as methotrexate and biologic immunomodulators, such as infliximab. These drugs are also known to cause serious side effects. Outside of prednisone and other glucocorticoids approved in the 1950s, none of these therapies are approved for the treatment of sarcoidosis and all are used based on limited clinical evidence. We believe the initial target population for efzofitimod will be patients whose disease is progressing, despite steroid treatment. However, even patients who are able to control their symptoms with steroids often experience such debilitating side effects that they are forced to choose between living with the burden of disease or the toxic effects of steroid treatment. Therefore, we also see an upside opportunity for efzofitimod as a steroid-sparing agent in patients who are responsive but unable to tolerate their steroid treatment. Combined, these populations represent an addressable market of roughly 150,000 to 200,000 patients in major markets, even with conservative market penetration and pricing assumptions, this represents a significant peak sales opportunity in sarcoidosis alone. Because this is an orphan disease and treatment options are limited, the FDA granted orphan drug designation for efzofitimod for the treatment of sarcoidosis. Additionally, we recently announced that FDA has also granted Fast Track designation for efzofitimod for the treatment of hormone sarcoidosis. The FDH Fast Track designation helps facilitate development and expedite the review of drugs to treat serious or life-threatening diseases with unmet medical needs. Fast Track designation provides certain benefits, including more frequent interactions with the FDA throughout the development program, as well as eligibility for accelerated approval, priority review and rolling review. This fast track designation underscores the significant need for a new therapy that provides clinically meaningful outcomes for patients living with pulmonary sarcoidosis and reinforces the potential of efzofitimod to be a transformative disease-modifying therapy and address a major unmet medical need. We see further upside potential for efzofitimod in other forms of ILD, where immunomodulatory treatment is the current standard of care. This includes indications such as scleroderma-related ILD other connective tissue disease-related ILDs and chronic hypersensitive in pneumonitis, among others. These diseases share overlapping immune pathology with sarcoidosis and are currently treated with similar drugs. Additionally, pneumonitis has been shown to be effective in animal models of these diseases. Taken collectively, the opportunity for efzofitimod in sarcoidosis and other ILDs represent $2 billion to $3 billion in peak sales. Let's take a moment to go over the data we generated for efzofitimod and some of the details around the current EFZO-FIT study. As a reminder, last September, we reported clinical proof-of-concept for efzofitimod based on positive results from a Phase Ib/IIa study in pulmonary sarcoidosis. The study, which included a four steroid paper demonstrated safety tolerability and a consistent dose response for efzofitimod on key efficacy endpoints and improvements compared to placebo, including measures of steroid reduction, lung function, sarcoidosis symptom measures and inflammatory biomarkers. According to medical experts, this is the first randomized placebo-controlled trial of any therapy for pulmonary sarcoidosis that demonstrates effect on physiologic and quality of life measures concurrent with steroid reduction. Based on findings from the Phase Ib/IIa study and feedback from the FDA, in May of this year, we announced plans to initiate the EFZO-FIT study. This is a global pivotal Phase III randomized, double-blind, placebo-controlled study to evaluate the efficacy and safety of efzofitimod in patients with pulmonary sarcoidosis. This is a 52-week study consisting of three parallel cohorts, randomized equally to either three milligrams per kilogram or five milligrams per kilogram of efzofitimod or placebo, dosed intravenously once a month for a total of 12 doses. The study intends to enroll 264 patients with pulmonary sarcoidosis at multiple centers in North America, Europe and Japan. The trial design incorporates a forced steroid paper design with the primary endpoint of the study being steroid reduction. Secondary endpoints include measures of lung function and sarcoidosis symptoms. The trial design for EFZO-FIT is based on key learnings from the Phase Ib/IIa trial that we believe sets up this study for clinical and regulatory success. This includes takeaways and from the four steroid taper and results for steroid reduction in the post-taper period. In the 1b/2a study, which was a six-month trial, patients underwent a forced steroid taper to 5 milligrams with the option to be titrated to zero at week 16 based on symptoms. We learned that patients could generally handle the force taper. And even though an eight-week taper was aggressive, we found that those patients on efzofitimod were able to taper more successfully. To be able to best evaluate the efficacy of efzofitimod compared to placebo, in efzofit, patients will be forced fully taper their steroid to zero milligrams, though over 12 weeks instead of eight. We believe that by providing more time for the taper and tapering steroids completely -- and finally, by following patients for an additional 24 weeks compared to the prior study, we expect more patients receiving placebo to experience worsening symptoms requiring increased steroids compared to patients receiving efzofitimod. We also have adjusted the entry criteria for background steroids from a minimum of 10 milligrams in the 1b/2a study through a minimum of 7.5 milligrams of prednisone per day in the Phase 3. This aligns with feedback from physicians, but there are many patients who require a bit less than 10 milligrams of daily steroids to maintain their symptoms and could really benefit from a reduction. Even a reduction of 2 or 2.5 milligrams of daily steroids for these patients over the course of time, could be very impactful. On the whole, we believe these adjustments will enrich the study and build upon the positive findings from the Phase 1b/2a trial. Again, efzofit is the largest interventional study for patients with sarcoidosis to-date. With this study, efzofitimod, is positioned to be the first disease-modifying therapy to market for patients with this debilitating disease. And based on data to-date, we believe one that could reduce steroid burden, maintain lung function, and improve symptoms. I'll now turn the call over to Leslie Nangle, our VP of Research, to discuss our preclinical and discovery programs and our tRNA synthetases platform.