Thank you, Samantha. As Samantha mentioned, the first half of 2019 was an extremely busy and exciting period for Zai Lab, across a variety of fronts. We became a commercial-stage company with the launches of Optune and ZEJULA in Hong Kong. We made significant headway towards potentially getting these products approved in the Midland China, by securing priority review status for ZEJULA and Innovative Medical Device Designation for Optune. We've further expanded our portfolio with 2 new partnerships, and we continue building out our commercial and R&D infrastructure through the recruitment of top talent. While our press release from this morning provides an update on all of our programs, and we'll be happy to answer your questions on assets that are not covered in our prepared remarks, I'd like to focus my comments today on a few selected programs and related near-term catalysts. I'll start with niraparib or ZEJULA, a PARP inhibitor, approved globally for the treatment of ovarian cancer and in development of other solid tumors. We believe that it is a highly differentiated PARP inhibitor with affluent efficacy and safety profiles without the need for blocker testing and superior pharmacological properties, including once daily dosing, low drug-drug interactions and ability to cross the blood-brain barrier. I'm pleased to report that our commercial launches in the Hong Kong are performing ahead of our initial expectations. Based on IQVIA, formerly IMS data, ZEJULA is now the market-leading PARP inhibitor with market share in the Hong Kong of 66% in the second quarter of 2019. This is particularly impressive given that Lynparza has been on the market in the Hong Kong for more than 2 years. The launch curve for ZEJULA, during the first 6 months, is significantly ahead of that of Lynparza in the Hong Kong at similar phase. While it is a small market compared to Mainland China, we believe, our initial performance validated the compelling profile of the ZEJULA and the capabilities of our commercial team. We're also learning valuable lessons that can be applied to the Mainland launch to further position ZEJULA for success in our primary market. Our new drug application for niraparib for the second-line maintenance treatment of platinum-sensitive ovarian cancer patients was accepted by NMPA under priority review, recognizing both the urgency of the medical need and the importance of the niraparib as the novel therapeutic option for patients. We continue to expect an approval decision from NMPA in the coming months and are prepared for our commercial launch immediately following the potential approval. Through our ongoing clinical studies, which are not required for the initial approval, we're building a robust body of clinical evidence in China, that, we believe, will meaningfully support our planned commercial efforts and help differentiate the niraparib. We're very encouraged by the positive headline data released by our partner for the PRIMA study and are eagerly awaiting the full dataset. These data will be an important part of our submission for niraparib, as a first-line or combination treatment for ovarian cancer. This will be significant for us, as Lynparza, the only PARP inhibitor currently approved by NMPA, was only studied as a monotherapy in the first-line settings in patients with the gBRCA mutation, which represents just 15% of the total patient population. We're working closely with our partner GSK to identify label expansion opportunities, including small-cell and non-small cell lung cancer, gastric cancer and other tumor types. Turning to Optune. We recently received Innovative Medical Device Designation and are working closely with the NMPA to accelerate the approval of the product in China. In February, we held our formal launch event for Optune in the Hong Kong, following the regulatory approval late last year. Similar to the ZEJULA, Optune is outperforming our expectations in the Hong Kong, and the initial uptake curve in terms of patient number is among the best in all major market launched countries for Optune. We view this as an encouraging sign for the compelling clinical profile for Optune and the unmet medical need that it is addressing, ahead of the anticipated commercial launch in Mainland China. As a reminder, we build a broader Tumor Treating Fields technology as a potential pipeline in the products with GBM as a first indication. In May, our partner, Novocure, announced the U.S. FDA approval of TTF for the treatment of mesothelioma. There are a number of other solid tumor indications, for which TTF is currently being evaluated, including non-small lung cancer, brain metastases, pancreatic and ovarian cancers, and we look forward to supporting these trials as well as initiating our Phase II study in gastric cancer patients, which remains on track for the second half of this year. Now turning to margetuximab, license from our partner MacroGenics, for the treatment of HER2-positive breast and gastric cancers for Greater China. As Samantha mentioned, the top line results of the SOPHIA trial were presented in the ASCO, showing margetuximab plus chemotherapy significantly prolonged progression-free survival versus trastuzumab plus chemo in a head-to-head comparison. Our preliminary overall survival analysis was also presented and MacroGenics plans to have a second look of the OS data concurrently with their BLA filing by the end of this year. We are actively pursuing the development of the breast cancer indication in China by leveraging the SOPHIA data, and we'll participate in the Phase III MAHOGANY trial in gastric cancer. Looking at recent business development initiatives, we added 2 very exciting products to our portfolio in the last several months. In June, we've announced an agreement with Deciphera Pharmaceuticals, giving out exclusive Greater China asset to their lead product candidate, Ripretinib, a KIT and PDGFR-alpha kinase switch control inhibitor, in development for gastrointestinal stromal tumors or GIST. Several weeks ago, Deciphera reported positive top line results for INVICTUS, their Phase III pivotal study of ripretinib, as a fourth-line treatment for GIST. The study demonstrated that ripretinib significantly prolonged improved progression-free survival versus placebo with a median PFS in the ripretinib arm of 6.3 months versus 1 month in the placebo arm and significantly reduced the risk of disease progression or death by 85% or have a ratio of 0.15. In an exploratory analysis, ripretinib also extended overall survival versus placebo, 15.1 versus 6.6 months or has a ratio of 0.36. These data compare favorable with avapritinib, which was only studied in a single arm trial in the fourth-line settings. Based on these impressive data, Deciphera plans to submit its NDA to the U.S. FDA in the first quarter of 2020. Ripretinib is also being evaluated in a Phase III INTRIGUE trial, as a second-line treatment for GIST, which has the potential to be a first-line therapy, not only in China, but globally. Zai Lab and -- with Deciphera intent to expand the INTRIGUE study to potentially include clinical trial site in China, so that we can concurrently submit marketing application in China, if the data is positive. More recently, in early July, we announced an agreement with Incyte for the development and commercialization of Altral, an anti-PD-1 monoclonal antibody in Greater China. As we have outlined previously, we believe that, based on its profile, Altral has the potential to be a highly competitive PD-1 inhibitor. This transaction was important for us on a number of levels, most notably, for the combination potential with certain other oncology assets in our portfolio. Site partner, MacroGenics, the original developer of Altral, has already been evaluating the combination of another product candidate, for which we hold Greater China right, margetuximab with Altral in the global Phase III MAHOGANY trial in gastric cancer. Owning 012 in the Greater China market will enable us to harmonize our development work and own both components of the combination. Furthermore, we have multiple compound in our current clinical-stage portfolio that can work synergistically with an anti-PD-1 and have the resources necessary to move these programs forward. With that, I will hand the call over to Billy Cho, our financial -- Chief Financial Officer, who will provide an overview of our financial highlights. Of course, we're able -- available to answer questions on these and other Zai Lab programs during the Q&A section of the call. Billy?