Pieris Pharmaceuticals, Inc.

and welcome to Purist Pharmaceuticals Q1 earnings 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. As a reminder, this conference is being recorded. I would now like to turn the conference over to your host, Tom Burrs, Vice President Finance. Please go ahead. Thank you.

Good morning, everyone, and thank you for joining us for our first quarter 2021 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 Olwell, our 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.piris.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 purists, including statements relating to the timing and progress of our clinical trials and pre-clinical programs, our partnerships and our financial position, and actual results or 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.

Well, thank you, Tom, and thank you to everyone for joining us today for our 2021 first quarter earnings call. The last few months have been very productive and marked by significant accomplishments as we advanced our proprietary and partner pipeline and leveraged existing and new alliances to materially bolster our balance sheet. Putting the past few weeks into perspective, we have generated $46 million in cash flow through milestone achievement, equity investments by partners AstraZeneca and Cgen, and the addition of a new partner. while also securing drug supply for a key combination study for our most advanced IO asset. We can and will continue to use partnerships and the power of non-dilutive funding mechanisms to reach significant corporate inflection points. PIRIS is the proprietor of a class of next-generation therapeutic polypeptides called anticalins, and we are focusing the development of anticalins in two areas. One, inhaled delivery for respiratory disease, and two, my specifics in immuno-oncology. I will first share some exciting updates from our respiratory pipeline, and I'm pleased to begin by announcing that patient dosing with PRSO60 has begun in the first part of a global Phase IIa study. PRSO60 is an IL-4 receptor alpha antagonist we are developing for moderate to severe asthma in collaboration with AstraZeneca, and it's our lead respiratory program. The first part of this two-part study is evaluating the safety and pharmacokinetics of the dry powder formulation of O60 in moderate asthmatics controlled on standard of care asthma therapy over four weeks. The second part of the study will then evaluate the efficacy, safety, and pharmacokinetics of PRS-O60 in moderate uncontrolled asthmatics over four weeks. The primary endpoint of the study will be FEV1 improvement compared to placebos. Last quarter, we announced the achievement of a $13 million milestone payment in connection with the initiation of this clinical study alongside a $10 million equity investment from AstraZeneca in connection with the restructuring of certain financial terms for PRS-060 in a manner that does not impact the overall value split of the asset between PIRIS and AstraZeneca. We are pleased with AstraZeneca's commitment to this program and to this collaboration more broadly, which also includes four Discovery Stage programs that are currently under active collaboration. In addition to our partnered respiratory programs, we are also developing a number of proprietary programs and look forward to sharing additional details, including IND plans for one of these respiratory programs later this year. Looking beyond our respiratory franchise, I would now like to discuss the progress we have made in our immuno-oncology pipeline. Our immuno-oncology pipeline is concentrated around our expertise in 4,1-BB-based bispecifics. We remain enthusiastic about 4,1-BB as a target, which is an immune cell co-stimulatory receptor that is overexpressed on activated T cells and natural killer cells in particular. and whose activation drives improved metabolic fitness of these cells. We have designed our 4-1-BB base by specifics with the objective of agonizing 4-1-BB locally to leverage its benefits while overcoming systemic and off-target side effects that have plagued systemically active 4-1-BB agonists. We were the first company to bring a 4-1-BB base by specific into the clinic, which is now progressing into phase two. And we have a number of 4-1-BB-based bispecific programs following that lead. SINRA Bifusp Alpha, also known as PRS-343 or SINRA, is our lead 4-1-BB clinical program. SINRA is a 4-1-BB HER2 bispecific that we have tested in two Phase I studies. Last month, we presented a clinical data update from the Phase I monotherapy study of SINRA at AACR. disclosing additional clinical benefit at the highest dose, including an additional confirmed durable partial response, three additional patients with stable diseases best response, and overall durable benefit. SINRA has shown a clear dose response and a 401 driven mode of action, and clinical benefit was observed in patients with cold tumors as well as those with HER2 low expressing tumors. SINRA has shown an acceptable safety profile at all doses tested with no dose-limiting toxicities. These findings provide the rationale for advancing this asset into a Phase II trial in HER2-expressing gastric cancer, a tumor type that continues to derive benefit from immunomodulatory therapies. As recently demonstrated by the Keynote 811 clinical study outcome, which led to the approval of pembrolizumab when added to the first-line standard of care, trastuzumab, and chemotherapy. The dose-dependent activity we are seeing with SINRA supports our recommended Phase II dose, which consists of a two-cycle loading dose at 18 mg per kg on a Q2 weekly regimen, followed by an 8 mg per kg Q2 weekly regimen in subsequent cycles. As a reminder, the Phase II study will be a two-arm study. The first arm will We'll evaluate SINRA in HER2-high gastric cancer in combination with ramicerumab and paclitaxel, with Lilly supplying ramicerumab at no cost to PURIS as part of a trial collaboration agreement. We expect to begin enrolling this 20-patient study arm later this summer, focusing on the U.S. and South Korea, where gastric cancer has a high prevalence. We are setting a high bar for go-no-go in our planned interim analysis of this study to ensure that we remain competitive with the evolving treatment landscape, and we'll be looking at a composite of efficacy measures, including durability and safety, in addition to objective response rate, or ORR. We are setting the ORR target at a minimum of 50% at this interim analysis, which is higher than the 28% ORR benchmark established by Ramiserumab and Paclitaxel and takes into consideration potential emerging standard of care and its bar we believe we can achieve given the activity we have observed with SINRA to date and the complementary mode of action in this combination. We believe that setting stringent criteria for advancement of our proprietary assets will help to ensure prudent and judicious use of our corporate resources and that achieving these criteria can translate into meaningful value for patients and shareholders. The second arm of the study will enroll 20 patients with HER2-low gastric cancer and will evaluate SINRA in combination with tucatinib, which will be supplied by our partner, CGEN, at no cost to PURIS. In addition to the data we generated collaboratively with CGEN that showed synergy between tucatinib and SINRA in enhancing the 4-1-Bb mediated immune cell activation. The data we presented at this year's AACR conference also support that SINRA is active in the HER2 low tumor setting as we observed clinical benefit in multiple HER2 low patients receiving SINRA as a monotherapy coupled with pharmacodynamic data that demonstrate 4,1BB agonism in these HER2 low patients. We believe it is encouraging that When paired with Ducatinib, SINRA may show clinical benefit in a setting where many other HER2-targeting drugs have shown only minimal activity. HER2-low gastric cancer therefore presents a high unmet medical need and is a sizable market opportunity. And as in the HER2-high arm of this study, we are setting a high bar for success for the HER2-low arm, looking at the same composite of efficacy measures, including durability, and safety in addition to ORR. Here, we believe that achieving at least a 40% ORR would be a significant improvement over the 28% ORR demonstrated by standard-of-care ramicerumab and paclitaxel in light of the marginal activity of other agents tested in this setting. We are excited to study this novel combination regimen with CJEN, who made a $13 million strategic equity investment in PIRIS in collaboration and in connection with the amendment of our existing immuno-oncology collaboration agreement last quarter. As we are making the necessary preparations for the start of the Phase 2 study of SINRA, we are also working hard alongside our partner, Servier, in anticipation of advancing PRS-344, which is a 4-1-BB-PD-L1 bispecific into Phase 1 later this year. Last month, We also presented preclinical data for 344 at AACR, demonstrating superiority to the combination of PD-L1 and 4,1-BB targeting molecules. As a reminder, we hold exclusive commercialization rights for PRS-344 in the United States and will receive royalties on ex-US sales by Servier for this program. Servier is also responsible for further development of PRS-352 an undisclosed immuno-oncology bispecific that is also part of our collaboration. Finally, we also recently entered into a license and collaboration agreement granting Boston Pharmaceuticals exclusive worldwide rights to PRS-342, a preclinical 411BGPC3 immuno-oncology bispecific. Under the terms of that agreement, PRS received an upfront payment of $10 million and is further entitled to receive up to around $350 million in milestone payments, tiered royalties up to low double digits on sales of the treatment if successfully approved and commercialized, and a share of certain subsequent sub-licensing revenue. PIRIS will collaborate with Boston Pharmaceuticals to advance the program towards an IND submission. Boston Pharmaceuticals has a strong leadership team and proven track record of developing a broad range of assets, including oncology. And we look forward to the advancement of this novel next-generation bispecific, which follows in the localized 4-1-B-B agonism mode of action of SINRA. So in conclusion, with our focused investments in SINRA Buffus Alpha and our partnerships with Servier, C-Gen, and Boston Pharmaceuticals, We have placed our immuno-oncology bispecifics pipeline on solid footing, and we look forward to the progression of multiple assets into the clinical stage beyond SINRA, driven by material ongoing investments by these partners. This concludes my prepared remarks, and I would now like to hand the call back over to Tom to guide you through our first quarter 2021 financial results. Over to you, Tom.