Paul Foster
Analyst · Leerink Partners. Your line is now open
Thank you, Bassil. I’ll start today by XmAb5871 our first in class monoclonal antibody in Phase 2 development for IgG4-RD and SLE. XmAb5871 targets CD19 with its variable demand and uses a proprietary XmAb immune inhibitor Fc domain to target Fc gamma receptor R2B, a receptor that inhibits B-cell function. Now at the ACR Annual Meeting in November, Dr. Johnstone the principal investigator presented preliminary data from our ongoing Phase 2 study in IgG4-RD we are very encouraged by these early results which show that 9 of 11 treated patients, or 82% achieved an initial response to therapy of at least a three point reduction in the IgG4-RD responder index within the first two weeks of the first dose. Five patients attaining disease remission or responder index is zero during this study and achievement that was well tolerated with no serious adverse events reported as of a data cut-off of October 31, 2016. As a reminder, this is a single-arm pilot study designed to evaluate the effective every other weak IV administration of XmAb5871 on disease activity in patients with active IgG4-RD. The last of 15 planned patients was enrolled this January. The patients will receive up to 24-weeks of treatment in the primary endpoint is to evaluate the portion of patients with an improvement in the IgG4-RD activity as defined by a decrease in the responder index. We are on track to report topline data from this trial this year and as Bassil noted, plan to engage with the FDA to discuss future development plans including clinical trial design and potential registration requirements in the months ahead. We also continue to progress our Phase 2 randomized double blind placebo control study in SLE and hope to report initial data in 2018. This study is designed to evaluate the ability of XmAb5871 to maintain lower levels of – disease activity following a brief course of inter muscular survey therapy and in the absence of immune suppressive medication. As we described previously, we believe this innovated trial design will enable us to access the effective XmAb5871 on SLE disease activity in less timing with fewer patients compared to standard SLE trials. The trial will enroll approximately 90 SLE patients for up to 24-weeks for the one-to-one randomization of XmAb5871 to placebo. Finally, we expect to report data from a Phase 1 study of the subcutaneous administration of XmAb5871 in the first half of 2017. Now onto XmAb7195 our first in class monoclonal antibody that targets IGE with its variable demand and uses the same XmAb and new inhibitor Fc domain as XmAb5871 to target Fc gamma receptor 2B. XmAb7195 has three distinct mechanisms of action for reducing IG levels, it’s sequesters free IgE to block IgE signaling, it suppresses B-cell differentiation into IgE secreting plasma cells and it enables the rapid clearance of IgE from circulation, via high FcγRIIb binding and breakdown in endothelial cells. In the Phase 1a trial presented at the ATS International Conference in May, intravenous administration of XmAb7195 induced a rapid and potent suppression of free IgE below the limit of detection including from single doses and 75% of high IgE subjects. In addition, total IgE, basophil surface-bound IgE and basophil IgE receptor levels showed large and sustained reductions for nearly all subjects. XmAb7195 was generally well tolerated, with transient, asymptomatic thrombocytopenia reported at doses ≥ 2.0 mg/kg. We believe XmAb7195 ability to effectively reduce IgE including in high IgE patients gives XmAb7195 potential in a range of allergic disease including allergic asthma and food allergy. We are currently evaluating a subcutaneously administered formulation of XmAb7195 in a Phase 1b trial and we expect to report topline results this year. Next, I’d like to provide updates on our expanding XmAb by specific oncology portfolio. Our bispecific antibody programs were built on a novel XmAb SE domain which is a scaffold for two or more different antigen binding demands. Result is a single molecule that combine two multiple targets simultaneously. This plug and play demand allows us to rapidly create drug candidates by combining any two binding domains, while also conferring additional benefits, including long [Indiscernible] half life, stability and ease of manufacture. Our lead bispecific programs are tumor-targeted antibodies that contain both a tumor antigen binding domain and a cytotoxic T-cell binding domain. These bispecific antibodies activate T cells for the highly potent and targeted killing of malignant cells. In September 2016, we initiated a Phase 1 trial of our lead bispecific oncology candidate, XmAb14045, in acute myeloid leukaemia and other CD123-expressing hematologic malignancies. XmAb14045 engages the immune system against AML by binding the CD123 of protein on AML cells and to CD3 approaching on cytotoxic T-cells thus activating a targeted T-cell immune response against the cancer cells. In preclinical studies, XmAb14045 showed highly effective and potent depletion of target cells from a well tolerated single IV dose. Our Phase 1 trial is an open-label, multi-dose, dose escalation study designed to evaluate the safety and tolerability of weekly IV administration of XmAb14045 for up to eight weeks in approximately 60 patients. The study is also designed to determine the maximum tolerated dose after the first and subsequent infusions. We hope to announce initial data in 2017 pending alignment with our partner Novartis and the timing. Our second bispecific oncology program, XmAb13676, binds the CD3 on T-cells, but targets CD20 for the treatment of B-cell malignancies. In February 2017 we started a Phase 1 clinical trial for XmAb13676, and expect to announce initial data in 2018, again pending alignment with our partner Novartis. In June we announced two pre-clinical additions to our bispecific oncology pipeline, XmAb18087 and XmAb20717, for which we expect to file INDs in 2017 and 2018 respectively. XmAb18087 targets SSTR2 and CD3 for the treatment of neuroendocrine tumors and XmAb20717, our first candidate to simultaneously engage two T-Cell checkpoint targets PD1 and CTLA4 for potential use in multiple oncology indications. This dual checkpoint bispecific antibody has the potential to improve the selectivity of combination checkpoint inhibitor therapy and eliminate the need for multiple checkpoint antibodies. Now I will turn it back to Bassil.