Bassil Dahiyat
Analyst · Leerink Partners. Your line is open
Thanks, Hannah, and good afternoon, everyone. Thank you for joining us. Xencor spent the last several years expanding and advancing a broad pipeline of XmAb antibody drug candidates based on XmAb antibody engineering platform, which is a small set of antibody FC domains and sequences we’ve slightly modified to improve natural antibody functions such as immune regulation and antigen clearance, cytotoxicity, circulating half-life or to create bispecific antibody structures that are stable, long-acting and readily produced. Today, XmAb-based antibodies are being developed internally by Xencor and by our partners in 11 different clinical stage programs for the treatment of a wide array of diseases. This includes four programs that we are advancing internally, with multiple additional programs we expect to start clinical trials for the next 18 months. The breadth of this pipeline is enabled by the XmAb platform’s portability, our ability to plug and play an FC domain we’ve engineered for particular property into multiple new antibodies. Now, we had several updates for our internal portfolio in the second quarter. In May, we announced receipt of orphan drug designation for our lead compound XmAb5871 in patients with IgG4-Related Disease or IgG4-RD. And in June we announce updated interim data from our ongoing study in this indication, which showed the 14 of 15 treated patients responded to the therapy with six achieving remissions. We expect top-line results in this study later this year and we are engaging with the USFDA to discuss the development plans, future trials and potential registration requirements in this indication. We also expect top-line results from our subcutaneous administration Phase I study of XmAb7195 by year end and initial data from our Phase I studies of XmAb14045 and 13676 in 2018 pending alignment with our partner Novartis. Overall, we expect to have proof-of-concept data for these four lead programs by the end of 2018. This will allow us to select the best program or program continually advance into later stages of development as we continue to mature Xencor into a fully integrated biotech company. And we are planning to file INDs for our next two bispecific oncology programs, XmAb18087 and XmAb20717 in late 2018 and – late 2017 I should say and in 2018 with more programs to follow. With that, I will now get into the specifics of our clinical and preclinical programs. Starting with XmAb5871, now that’s our first-in-class monoclonal antibody currently in Phase 2 development for IgG4-RD and systemic lupus erythematosus or SLE. Both IgG4-RD and SLE are diseases with a strong rationale for B-cell inhibition in which we can execute efficient Phase 2 trials and potentially address areas of high unmet needs. 5871 works by targeting CD19 with its variable domain, and with our XmAb immune inhibitor Fc domain used to target FcyRIIb, an FC receptor that inhibits B-cell function. As the first known drug candidate to target FcyRIIb, 5871 offers patients a differentiated product profile and a unique mechanism of actions. It potently and broadly blocks B-cell activation without depleting the B-cells creating a reversible inhibition that can be stopped to help avoid long-term immune suppression. Now as we announced last quarter, subcutaneous dosing of 5871 is well-tolerated and supports every other week dosing, which offers patients and doctors a simple more flexible treatment option than infusions. We provide an update for 5871 and IgG4-RD in June. Now this disease, IgG4-RD is a newly defined, fibro-inflammatory autoimmune sort of typically affects multiple organs causing tumor like swelling and variable degree of fibrosis and potentially irreversible organ damage. It’s characterized by a lymphoplasmacytic infiltrate in the affected organs rich in IgG4 positive plasma cells. Now there is no proved therapies for the approximately 40,000 people affected in the U.S. and Corticosteroids is the current standard of care. We believe we could be at the forefront of providing a treatment option to these patients and we are discussing future development plans including clinical trial design and potential registration requirements with the FDA this year. Now at the European – the Annual European Congress of Rheumatology or EULAR Meeting, in June, we reported updated interim data from our ongoing open-label, single-arm Phase 2 study which showed that 14 of 15 treated patients or 93% achieved a responsive therapy with at least a 3 point reduction in the IgG4-RD responder index. This includes 12 patients or 80% who achieved this response within two weeks of their first dose. Responses continued to deepen over time with six patients achieving remission or responder index of zero. Now 5871 continues to be well-tolerated, with all drug-related adverse event graded as mild or moderate and no AE reported more than two patients. We are very encouraged by the rapid initial responses of the therapy has observed in our interim dataset and we look forward to reporting top-line data from the trial later this year. We also continue to progress our Phase 2 study in SLE. As a reminder, this is a randomized, double-blind placebo-controlled multiple dose study design to evaluate XmAb5871’s ability to maintain the improvement in SLE disease activity after a short course of intramuscular steroid therapy and in the absence of immunosuppressant medication. We designed this study to assess 5871effect on disease activity with a shorter term to endpoint in the fewer patients compared to standard SLE trials and we expect to report data in late 2018 or early 2019. Turning now to XmAb7195, our first-in-class monoclonal antibody that targets IgE with its variable domain and uses the same XmAb immune inhibitor Fc domain as XmAb 5871 to target FcyRIIb. In contrast to approved IgE targeting therapies which block IgE receptor binding only, 7195 with its immune inhibitor Fc domain leverages three distinct mechanisms to reduce IgE levels. Its clusters free IgE and blocks its IgE signaling through its receptor. It also suppresses B-cell differentiation into IgE secreting plasma cells and finally and critically it enables it rapidly clears IgE from the circulation. Now while existing therapies valued IgE as a robust target for reducing asthma symptoms and disability, potentially significant fraction of patients are not addressed due to suboptimal potency. 7195 has induced a rapid and potent suppression of pre-IgE below level of detection from single-doses in 75% of high IgE subjects , subjects typically contraindicative from receiving existing IgE reducing or IgE blocking therapies. Now based on these results, we believe 7195 has the potential to be an important treatment for allergic diseases and we continue to evaluate our subcutaneously administered formulas of 7195 in a Phase 1b trial and are on track to announce top-line data later this year. Now I will shift to our bispecific oncology pipeline. Our bispecific antibodies are built on a novel Fc domain, which provides robust scaffold for two or more different antigen binding domains. The result of the single molecular and simultaneously binded multiple targets while preserving important properties of native antibodies like long-circulating half life, stability and ease of manufacture. Our lead bispecific programs are tumor-targeted antibodies that contain a tumor antigen binding domain on one side, and a cytotoxic T-cell binding domain on the other. They work by activating T-cells at the site of a tumor for highly potent killing in malignant cells. Now importantly, the format of our bispecifics allows us to tune their potency to balance anti-tumor activity with the reduction of immune toxicity that turns out from T-cell activation. We are currently evaluating in the clinic two bispecific oncology candidates in Phase 1 studies. The first is XmAb14045 for the treatment of acute myeloid leukemia and other CD-123 expressing hematologic malignancies. Now 14045 engages the immune system by binding CD-123 approaching highly expressed myeloid leukemia stem cells and it is associated also with thorough prognosis. Now, 14045 binds to CD-3 on the other side of the molecule and that’s approaching on cytotoxic T-cells, and it activates the T-Cells for highly potent and targeted killing of CD-123 expressing tumor cells. The second candidate, XmAb13676 binds the CD3 and CD20, which is a highly expressed antigen on B-cell tumors like CLO and NHL. Now both programs are partnered with Novartis who licensed ex U.S. commercial rights from us in June of 2016 and pending alignment with them, we expect to report initial data from both studies in 2018. Now our expanding bispecific pipeline also includes XmAb 18087 and XmAb20717. We’ve planned to file an IND for 18087, which targets SSTR2 or somatostatin receptor 2 and CD3 for the treatment of neuroendocrine tumors, later this year. XmAb20717 is our first candidate that simultaneously target two T-cell checkpoint targets, PD1 and CTLA4 and it’s designed for using multiple oncology indications. As a dual checkpoint antibody, we believe 20717 can improve the selectivity of combination checkpoint inhibitor therapies and eliminate the need for multiple antibodies and combos. And we look forward to advancing it to the clinic in 2018. We are also continuing the preclinical development of several additional programs with additional INDs to follow in 2018. Next a quick update on our partnerships. Nine pharmaceutical companies and the NIH are advancing drug candidates either discovered at Xencor or that rely on our proprietary XmAb Fc domain. This includes seven programs currently undergoing clinical testing. In the second quarter, our partner MorphoSys initiated the pivotal Phase 3 portion of its Phase 2/3 study of MOR208, formerly called XmAb5574 in combination with bendamustine diffuse large B-cell lymphoma. This triggered a milestone payment to Xencor of $12.5 million. MOR208 uses our Cytotoxic Fc Domain to target CD19 and is in development for B-cell malignancies broadly. Now with this advancement, we now have three partnered programs in Phase 3 testing. The other is being Talacotuzumab, which is in development by CSL Limited and its licensee Janssen and it also utilizes our XmAb cytotoxic Fc domain. An undisclosed program is in development by Alexion in Phase 3 and that one utilizes our half-life extension Fc domain. Finally, I’d also like to welcome a new team member at Xencor. In the second quarter we welcomed Dr. Raphael Clynes, as Vice President of Translational Biology. In this newly-created role, Dr. Clynes will focus on the biological mechanisms of our antibody drug candidates with a particular focus on immuno-oncology. Now with that, I will turn the call over to John to review our second quarter and first half financial results.