Pieris Pharmaceuticals, Inc.

Greetings, and welcome to Pierre's Pharmaceuticals, Inc. year-end earnings conference call. At this time, all participants are in a listen-only mode. A question-and-answer session will follow the formal presentation. If anyone should require operator assistance during the conference, please press star zero on your telephone keypad. Please note this conference is being recorded. I will now turn the conference over to your host, Tom Burris. You may begin.

Thank you. Good morning, everyone, and thank you for joining us for our year-end 2020 conference call and corporate update. On the call today, we have Steve Yoder, our president and CEO, who will provide a corporate overview and outlook on our pipeline, Keto Kaufman, our chief scientific officer, and Shane Owell, our SVP and head of translational science, who will be available for a Q&A. You can access the press release released this morning on the investor relations page of our website at www.purist.com. Before we begin, I'd like to caution that comments made during this conference call may contain forward-looking statements involving risks and uncertainties regarding the operations and future results of operations of PURIS, including statements relating to the timing and progress of our clinical trials and preclinical programs. Our partnerships and our financial position and actual results for events may differ materially from those expressed or implied by such forward-looking statements. Factors that might cause such differences are described in our filings with the SEC, including our annual, quarterly, and current reports. The information being presented is only accurate as of today, and PIERCE undertakes no obligation to update any statements to reflect future events or circumstances. I will now turn the call over to Steve.

Thank you, Tom, and thank you to everyone for joining us today for our 2020 year earnings call. It's been a busy and exciting past few days. including this morning's update within our AstraZeneca collaboration. But before diving into those updates, as well as a recap of some of last year's highlights and an outline of our future plans, I would like to simply remind everyone that we're building a proprietary and partner pipeline of large molecules called anticalin proteins, which are engineered versions of naturally occurring proteins called lipocalins. Lipocalins are small, specific binding proteins with good drug-like properties. we're currently focused in two areas, inhaled antichalin proteins to treat respiratory diseases locally, and bispecifics designed to activate the immune system of cancer patients locally. In both cases, the local or focused approach that antichalin proteins offer is intended to drive superior outcomes for patients compared to systemically active agents. Beginning with our respiratory franchise, I first will provide an update on PRSO60 or AZD1402, an IL-4 receptor alpha antagonist we are developing for moderate to severe asthma in collaboration with AstraZeneca. We are pleased to have announced earlier today the achievement of a 13 million US dollar milestone payment in connection with the initiation of the Phase IIa study for this program. In this global two-part Phase IIa study, PRSO60 will be evaluated at up to three dose levels in an inhaled dry powder formulation versus placebo. The first part of the study will evaluate the compound in approximately 45 moderate asthmatics controlled on standard of care asthma therapy over four weeks to establish the safety and pharmacokinetics of the dry powder formulation. The second part of the study will assess its efficacy, safety, and pharmacokinetics in up to three arms plus a placebo arm and up to 360 moderate uncontrolled asthmatics with the blood eosinophil count of greater than or equal to 150 cells per microliter and fractional exhaled nitric oxide or pheno greater than or equal to 25 parts per billion. Patients will be dosed and monitored over four weeks with FEV1 improvement compared to placebo as the primary end point. The initiation of this trial is a significant milestone for our respiratory franchise. This program remains a high-priority one for PIRAS, and we look forward to continuing our collaboration with AstraZeneca on this program and sharing the Phase IIa results next year. Additionally, we recently amended our agreement with AstraZeneca to restructure certain commercial terms for PRSO60 by adjusting various milestones and royalty provisions while fundamentally maintaining the overall value split between the two companies. In connection with the amendment, AstraZeneca is also making a 10 million US dollar equity investment in Puris. We believe this investment further strengthens our joint vision for the future of inhaled biologics and demonstrates AstraZeneca's ongoing commitment to our alliance. Beyond this lead respiratory program, we have several other inhaled respiratory programs in development. There are four Discovery Stage programs that are part of the five-program collaboration with AstraZeneca, and there are multiple fully proprietary programs we are developing outside our partnership with AstraZeneca. We have continued to make progress on our proprietary programs, and we envision disclosing program details, including IND plans, for one of those programs later this year. Now, turning from our respiratory franchise, I will now give an update on our immuno-oncology pipeline, which is focused on a target known as 4-1-BB or CD137, which is an immune cell co-stimulatory receptor that is expressed on activated T-cells and natural killer cells in particular. PIRIS is a leader in the 4-1-BB space, and our data-driven belief in this target underpins most of what we're doing in immuno-oncology. Our localized 401 agonism approach was designed to overcome the challenges that systemically active 401 agonists have faced in the clinical setting, rendering them ineffective in achieving a suitable therapeutic window. We believe our 401 based by specifics can open up that window and take advantage of the biology fundamentals of 401 . And what makes 401 so special is that its activation is believed to provide a critical signal that leads to increased T-cell proliferation, cytotoxicity and cytokine secretion, and enhanced T-cell memory, among other effects, which collectively help to mediate effective and durable anti-tumor activity. Our lead program, with international non-proprietary name Sinribifus Alpha, which you all know as PRS343, and from here I'll often refer to as SINRA, is a 401 HER2 bispecific and the first tumor-targeted 401 agonist to have entered clinical trials. It was engineered specifically to take advantage of the potential of 401 while avoiding off-tissue toxicity limitations. Clinical data we have generated, which are based on a monotherapy dose escalation study, and a combination dose escalation study with atezolizumab to Centric, provided under a drug supply agreement with Roche, they have demonstrated clinical benefit linked to biomarker evidence indicative of a 4-1-BB-driven mechanism of action. And not only does SINRA demonstrate clinical activity, but it does so with an acceptable safety and tolerability profile. Most recently, we presented results from both studies at the 2020 European Society for Medical Oncology, or ESMO, virtual congress. The results confirm that SINRA provides durable clinical benefit, including a durable confirmed complete response, in heavily pretreated patients across multiple HER2-positive tumor types. The observed clinical benefit coincides with significant expansion of CD8 T cells observed in longitudinal biopsies of responders and a substantial increase of soluble 4-1-BB in the active dose cohorts, demonstrating 401BB activation. Data presented at ESMO included several patients from the highest dose cohort, cohort 13B, which is an 18 milligram per kilogram dose, dosed Q2 weekly. Those patients who had only recently enrolled in the study as of the conference cutoff date and had not yet reached the first radiological assessment under resist criteria. At AACR on April 10th, we will present additional clinical benefit and safety data for these patients, as well as additional biomarker data across all active dose cohorts. Our objective in presenting additional data is to lay further foundation for our phase two trial plans, including the development of SINRA in both the HER2 high and HER2 low settings. As announced last year, we intend to build on the positive clinical activity we observed with SINRA in the HER2 high setting, that is IHC2+, and ISH positive, as well as IHC3+, through a study of SINRA in gastric cancer patients in combination with second-line standard of care, paclitaxel, and ramiserumab. For this study, Lilly is supplying ramiserumab under a drug supply agreement. Given the clinical activity we observed in monotherapy in heavily pretreated patients, the positive safety profile, and the fundamental underpinnings of 401BV biology that drive T-cell proliferation, cytotoxicity, and memory, we are encouraged at the prospect of SINRA offering a meaningful treatment option to HER2-positive patients in what has become a very dynamic. And turning beyond the HER2-high gastric cancer setting, We are also excited to be exploring the combination of SINRA with tucisa-tucatinib for HER2-low gastric cancer patients. And we have recently signed a trial collaboration with C-Gen, who will supply tucatinib for this study. Based on SINRA's mode of action and data we have been generating, we believe the HER2-low setting is an area where SINRA can be particularly differentiated. The combination of SINRA and tucatinib is intended to address a high medical need in HER2-low-expressing gastric cancer patients who do not respond to traditional HER2-targeted therapies. Preclinical studies we generated in collaboration with CGEN show that tucatinib synergizes with SINRA to enhance 4-1-BB-mediated immune cell stimulation. This effect was observed across a range of HER2-expressing cell lines. not just IHC3+, but also IHC2+, and 1-plus cell lines regarded as HER2 low, including those where SINRA had limited single agent activity. In terms of the synergy at play here, we know that in general, tyrosine kinase inhibitors have been shown preclinically to upregulate or stabilize tumor cell surface HER2 expression. One hypothesis behind the synergy we're observing is that tucatinib can impact HER2 stabilization on tumor cells. which can facilitate increased clustering of SINRA on the tumor cell surface to further drive 4-1-BB cross-linking and therefore enhanced activation of immune cells. Not only does the HER2-low gastric cancer setting represent a sizable market opportunity, but also it's an area where competitor drugs that showed benefit in HER2-high gastric cancer have not fared as well in the HER2-low settings. We look forward to studying this combination and are pleased to be doing so with an existing supportive partner. Not only is Cgen providing Tucatinib for this study, but they recently also made a 13 million US dollar strategic equity investment in PIRIS in connection with the amendment of our existing immuno-oncology collaboration agreement. And we believe that this investment further strengthens our joint commitment to developing novel cancer therapies together. As we work on phase two initiation for these two studies, which we expect will begin this summer and will include a number of sites in South Korea and the US, we have dosed two of six intended patients in a small safety cohort that is progressing well and which employs the co-diluent technique we refined as part of our efforts to remove the partial clinical hold, which was listed by FDA in January of this year. Looking beyond SINRA and our immuno-oncology collaboration with CGEN, we are also working hard to advance PRS-344, a 4-1-BB PD-L1 bispecific under co-development with Servier. On April 10th, we will present what we believe are compelling preclinical data for 344 as part of a poster session at AACR. The presentation will showcase synergistic data, including in vitro data evaluating potential effects of combining 401 and PD-L1, and the effects of PRS-344 on CD8 T-cell, as well as dose-dependent anti-tumor response in in vivo preclinical models. We expect that the phase one trial of PRS-344 will begin this year. And as a reminder, PRS holds exclusive commercialization rights for PRS-344 in the United States and will receive royalties on ex-U.S. sales by Servier for this program. Additionally, within our Servier collaboration, we completed non-GLP preclinical work for PRS352, a preclinical stage program addressing undisclosed targets for immuno-oncology last year. Servier is fully responsible for further development of the program. This concludes my prepared remarks, and I would now like to hand the call back over to Tom to guide you through our year-end 2020 financial results. Over to you, Tom.