Thank you, Sarah. Good afternoon and thank you for joining us. We made excellent progress in the first half of the year and look forward to providing you a thorough update on our programs this afternoon. As you look at the business overall, our pipeline remains strong and well diversified. We have two programs advancing nicely in the clinic, a third poised to enter clinical before year-end, and a fourth lined up for 2020. We also made an important hire this summer that we believe will further strengthen our clinical development efforts and support the continued progress of our product pipeline. Dr. Diane Young has joined the Celldex team as a Senior Vice President and Chief Medical Officer. Diane is a medical oncologist and has led clinical and cross functional research and development teams responsible for the global development of numerous novel therapies from Phase I through successful product registrations. Most recently, Diane served as Chief Medical Officer of GTX, Inc., a public biopharmaceutical company focused on the development drugs that target nuclear hormone receptors. Previously, Diane spent 13 years at Novartis Oncology and senior leadership roles in global clinical development and medical affairs. As the head of oncology clinical development, she directed the clinical programs leading to successful regulatory approvals for more than a half a dozen important oncology drugs. Prior to Novartis, Diane held senior leadership positions in clinical development at the R.W. Johnson Pharmaceutical Research Institute of J&J as well as Hoffman-LaRoche and Sandoz. We are very pleased to have Diane on our team. She will join us at both medical and investor conferences this fall and I'm sure our shareholders will enjoy meeting her at these venues. We continue to strengthen our balance sheet to extend and direct our financial resources to the advancement of the progress we believe can bring the most value to both patients and shareholders. In direct support of this, in June, we decided to consolidate our Massachusetts laboratory and manufacturing facilities. The lease for the Needham Massachusetts facility will not be renewed and most functions and employees will be integrated into the company's Fall River manufacturing facilities. We estimate that this consolidation, along with a reduction in the square footage of our Hampton, New Jersey facility executed earlier this year, will decrease our facility footprint by over 35% and will save us over $3.5 million annually starting in the second half of 2020. With that, I'd like to turn to a review of our pipeline. I'm going to start with an update of the CDX-1140, CDX-0159 and our preclinical programs. Then I'm going to ask Dr. Margo Heath-Chiozzi, our Senior VP of Regulatory Affairs, to provide an update on CDX-3379. Margo has served as the medical lead for this program to date. Sam Martin, our CFO, will then review the financials before we open the call to your questions. CDX-1140 is a fully human antibody targeted to CD40, a key activator of the immune response which is found on dendritic cells, macrophages, B cells and several cancer types. Potent CD40 agonist antibodies have shown encouraging results in early clinical studies. However, systemic toxicity associated with broad CD40 activation has limited their dosing. We selected CDX-1140 based on its unique properties relative to other CD40 agonist antibodies. It binds to the CD40 receptor in a manner that results in a linear, non-dose-dependent agonist activity which may allow for higher systemic dosing and better tumor penetration at the optimal agonist levels. CDX-1140 does not require cross-linking through Fc receptor interactions for its agonist activity, allowing more consistent and controlled immune cell activation. Also, CDX-1140 does not interfere with the natural activation of CD40 by its ligand, which may further potentiate local immune responses. Finally, CDX-1140 had a strong safety profile, while demonstrating potent immune activation in our preclinical studies. The ongoing Phase I trial is a multidose, dose escalation study of CDX-1140 in patients with locally advanced, recurrent or metastatic solid tumors and B cell lymphomas. The study also includes a separate dose escalation arm of CDX-1140 in combination with CDX-301. CDX-301 is a potent dendritic cell growth factor that increases the number of these important cells which are a key target for CDX-1140. An important goal of this study is to achieve dosing levels of CDX-1140 that will provide good systemic exposure without dose-limiting toxicity. To this end, we have made excellent progress completing all eight cohorts in the monotherapy dose escalation arm. Importantly, based on biomarker data, CDX-1140 is demonstrating strong biological activity associated with CD40 activation. Currently, we are adding additional patients at the three highest dose levels to provide additional data in the selection of our recommended Phase II dose as we await completion of the dose escalation in the combination arm of the study. With CDX-1140 and 301 combination, we are nearing the close of the DLT window for the fourth of six potential cohorts at the 0.72 mg per kg. And assuming successful clearance. the 1.5 mg per kg combination cohort should open shortly. Overall, we are pleased with the data to date which have shown that CDX-1140 can be safely administered at doses that Celldex believes will support good tissue and tumor penetration and at doses significantly higher than most other potent agonists targeting CD40. Our next step is to add an additional arm to the study that will include the combination of PD-1 inhibitor with CDX-1140. This cohort is important as we'll be both enhancing the immune system with CDX-1140 and releasing the break on the immune system with the introduction of the checkpoint inhibitor. We are also exploring future combination opportunities with chemotherapy, radiation therapy and Celldex's potent CD27 agonist monoclonal antibody varlilumab. We are excited about the 1140 program and its clinical potential. We presented data from this study at AACR in early April and hope to present an update at the SITC meeting in November. Before year-end, we will also initiate a Phase I study of CDX-0159, our KIT antagonist antibody program in healthy subjects. CDX-0159 is a reengineered variant of CDX-0158. KIT is a key regulator of mast cells and preclinical and clinical data with CDX-0158 demonstrated a robust inhibition of mast cell activity and decreased mast cell numbers, supporting the concept that targeting KIT with an antagonist antibody can modulate mast cell activity and potentially provide clinical benefit in mast cell related diseases. CDX-0159 was redesigned to oblate Fc receptor interactions and effector functions and a proven safety profile, while preserving full KIT inhibitory activity. In addition, CDX-0159 was modified to provide extended half-life following administration. This Phase Ia study is designed to evaluate the safety profile, pharmacokinetics and pharmacodynamics of single ascending doses of CDX-0159 in healthy subjects. Following completion of the study, we plan to further study CDX-0159 in chronic idiopathic urticaria, CIU. CIU presents as itchy hives, angioedema or both for at least six weeks without a specific trigger. Multiple episodes can play out over years or even decades. The prevalence of CIU is estimated to be 0.5% to 1% of the total population or up to 3.2 million cases in the United States. About 50% of patients with CIU achieved symptomatic control with antihistamines and and leukotrienes receptor agonists such as Xolair. An IgE inhibitor provides relief for roughly half of the remaining antihistamine/leukotriene refractory patients. Consequently, there is need for more effective later line therapies. We believe targeting KIT with CDX-0159 represents a unique strategy in diseases involving mast cells such as CIU. We hope to present the scientific rationale and supportive data of our development strategy in CIU at a medical meeting this fall and will continue to keep you updated on this program. Before I hand the call over to Margo to discuss CDX-3379, I want to touch on our preclinical pipeline which had a strong showing at AACR in the second quarter. CDX-527, our first bispecific antibody program, combined CD27 mediated cell activation with PD-1 blockade. We have developed CDX-527 from our proprietary, highly active anti-PD-L1 and CD27 human antibodies and demonstrated the bispecific to be more potent than the combination of the individual antibodies in preclinical models. CDX-527 provides Celldex with its own PD-1 pathway inhibitor with potentially broader activity and sets us up for unique combinations within our own pipeline. We are currently initiating manufacturing activities for CDX-527 to support an IND targeted for 2020. We have also been making significant progress on developing lead candidates targeting the receptor tyrosine kinases, Tyro3, Axl and MerTK, collectively known as the TAMs. These receptors have been gaining importance in the immunotherapy field due to their role as checkpoint molecules on macrophages, dendritic cells and other immune cells where they can negatively regulate the antitumor immunity. We recently presented our progress on lead antibody characterizations for all three receptors at AACR. The antibodies targeting Tyro3, Axl and MerTK, all promote activation of human macrophages and dendritic cells and we look forward to moving these candidates towards development activities. With that overview, I will ask Margo to discuss the progress we've made with CDX-3379. Margo?