Thank you, operator. Hello, and welcome, everyone.

Today's earnings call will be led by Dr. Samantha Du, Zai Lab's Founder, CEO, and Chairperson.

She will be joined by Josh Smiley, President and Chief Operating Officer; Dr. Rafael Amado, President and Head of Global Research and Development; and Dr.

Yajing Chen, Chief Financial Officer. Dr.

Shan He, our Chief Business Officer, will also be available to answer questions during the Q&A portion of the call. As a reminder, during today's call, we will be making certain forward-looking statements based on our current expectations.

These statements are subject to numerous risks and uncertainties that may cause actual results to differ materially from what we expect due to a variety of factors, including those discussed in our SEC filings. We will also refer to adjusted loss from operations, which is a non-GAAP financial measure.

Please refer to our earnings release furnished with the SEC on May 7th, 2026, for additional information on this non-GAAP financial measure. At this time, it is my pleasure to turn the call over to Dr.

Samantha Du.

Thank you, Christine. Good morning and good evening, everyone.

Thank you for joining us today. Zai Lab is at a pivotal moment.

Since our founding, we have built a fully integrated R&D engine, capable of taking assets from discovery through global registrational studies, with the ability to design and execute multiple pivotal trials globally. The impact of these investments is beginning to emerge.

Our pipeline is expanding, our global assets are generating meaningful data, and our lead asset is in global pivotal stage. We are also leveraging AI and data-driven approaches across the organization to enhance speed, precision, and efficiency, strengthening overall execution and corporate productivity, which we expect will drive further results.

Last month, at AACR, we presented new data for [ZL-1310?] , that reinforced our conviction, including strong efficacy, both systemically and in the brain, in patients with small cell lung cancer, alongside a best-in-class safety profile.

We also announced global collaborations with Amgen and Boehringer Ingelheim to explore [ZL-1310?] as a potential backbone therapy in small cell lung cancer and neuroendocrine carcinomas, two cancer types with significant unmet medical need.

In late 2027, we expect to submit our first global BLA to the FDA, a defining milestone that marks our successful transformation to a global biotech company. Beyond [ZL-1310?]

, we're building a growing portfolio of global clinical programs, including ZL-1503 for atopic dermatitis, now in a Phase 1/1b study. This reflects the strength of our R&D engine, which combines rigorous science with operational speed and efficiency to advance differentiated assets into global development.

Our regional business remains commercially profitable, with a strong balance sheet. We're focused on strengthening our commercial capabilities and execution.

I am pleased to welcome Dr. Yi-Zhuo Wang as an operating partner to work with me to drive commercial performance and readiness ahead of upcoming launches.

The recent policy developments in the region, including the State Council directive, signal meaningful government support for innovative medicines, and we believe Zai Lab is well positioned to benefit over the medium to long term, given our first- and best-in-class portfolio. We're confident in Zai's future, which will be defined by our growing global and regional pipeline of differentiated assets.

With that, I'll now turn the call over to Rafael.

Thank you, Samantha. Over the past years, we have built a globally integrated R&D engine that spans from discovery through global registrational development, while also delivering on regional development across therapy areas.

Our ability to design and execute high-quality global studies with speed and discipline is a core strength that positions us well for development across regulatory geographies. We are embedding AI in R&D, including drug discovery and clinical trial design, to enhance the quality of our decisions and to more efficiently advance our pipeline.

The data we presented at AACR last month highlights the output of this engine across all our global pipeline that included both externally sourced and internally discovered products. Let me start with [ZL-1310?]

. In extensive-stage small cell lung cancer, at the go-forward dose of 1.6 milligrams per kilogram, [ZL-1310?]

demonstrated a confirmed intracranial overall response rate of 62.5% and a best overall intracranial response rate approaching 69%, including 4 complete responses. Grade 3 or higher treatment-related adverse events were approximately 16%.

Responses of this magnitude inside the brain in one of the most treatment-resistant tumor types in oncology are meaningful signals of differentiation. The safety data reinforce what we have consistently observed.

This is a best-in-class profile. Our registrational Phase 3 DELLEVATE study is enrolling well and is on track to complete enrollment in the first half of 2027, positioning us for an interim analysis and potential accelerated approval submission next year.

In extrapulmonary neuroendocrine carcinomas, a setting where there is no established standard of care in the second line and beyond, [ZL-1310?] demonstrated a confirmed ORR of 38.2%.

This compares favorably to currently used regimens, which typically show response rates of approximately 18% with limited durability. We're actively engaging with regulators on a potential registrational path and are well on our way recruiting into an extension single-arm study.

Depending on the outcomes of regulatory discussions, we could initiate a registrational or confirmatory study by year end. Now on the collaborations with Amgen and Boehringer Ingelheim, exploring [ZL-1310?]

in combination with T-cell engagers. The scientific rationale is straightforward.

[ZL-1310?] delivers rapid tumor debulking through targeted cytotoxicity, while T-cell engagers drive antigen-dependent immune-mediated killing.

The mechanisms are complementary. The toxicity profiles are expected to have limited overlap, and together, they have the potential to deepen and extend responses in ways neither mechanistic approach achieves alone.

A Phase 1 with Amgen, which includes a cohort of untreated patients with triple combination of [ZL-1310?] , IMDELLTRA, and IMFINZI, is already enrolling, and the BI study is expected to follow in the coming months.

We're also evaluating [ZL-1310?] in combination with PD-L1, with or without chemotherapy, in a Phase 1 study in first-line small cell lung cancer, with data expected later this year.

A chemo-sparing approach may allow for extended treatment duration compared to chemotherapy alone, where patients typically discontinue after 4 cycles. This is the basis of our Phase 3 strategy with IO, which we are actively discussing with regulators.

Beyond [ZL-1310?] , our global oncology pipeline continues to advance.

ZL-6201, our LRRC15 ADC, is already in the clinic. ZL-1311, our wholly owned MUC17-targeting T-cell engager, is expected to enter the clinic by year end.

We will provide updates as data mature. On the regional oncology side, we submitted a marketing authorization application for Tumor Treating Fields in locally advanced pancreatic cancer, and expect an approval for this indication by year end, and for Tivdak for cervical cancer in the coming months.

Turning to immunology, we recently presented preclinical data for ZL-1503, our IL-13/IL-31 receptor alpha bispecific, at Immunology 2026. The data show rapid and durable inhibition of both IL-13-driven inflammation and IL-31-mediated pruritus across disease models in nonhuman primates, with sustained effects following single dose.

We believe this data supports the potential for differentiated efficacy, less frequent dosing, and broad application across multiple atopic diseases, including asthma, rhinitis, and conjunctivitis. Initial Phase 1 data in healthy volunteers and atopic dermatitis patients are expected in the second half of this year.

Finally, in our regional immunology portfolio, our partner Vertex reported positive Phase 3 interim results from the RAINIER study of povetacicept in IgA nephropathy, achieving approximately a 50% reduction in proteinuria versus placebo and meeting both the primary and all secondary endpoints. I want to close with a broader point.

The progress I've described today reflects a pipeline strategy built on biological rationale, clinical differentiation, and execution, and an organization that now has the infrastructure to advance multiple programs simultaneously at speed and across geographies. We have significant data emerging throughout the year, and I look forward to providing those updates.

With that, I'll hand it over to Josh.

Thank you, Rafael, and hello, everyone. Let me start with our first quarter performance, which reflected Chinese New Year seasonality, as well as near-term product-specific dynamics.

Starting with ZEJULA, performance in the quarter was impacted by a shift in hospital utilization patterns following volume-based procurement for generic olaparib, and some incremental competitive pressure in the PARP inhibitor class. Our first-line positioning remains intact, supported by our label advantage, and we are working hard on stabilizing and driving demand.

On VYVGART, physician confidence remains strong, and our share within biologics is stable. We delivered double-digit volume growth year on year in the quarter, offset by a 12% price discount related to NRDL renewal.

On a full-year basis, we expect a similar level of volume growth as we continue to shape gMG treatment dynamics. The long-term opportunity stays significant.

Biologic penetration in the gMG maintenance setting remains around 15%, suggesting a runway for growth, plus upcoming Phase 3 readouts in new indications, such as IIM and Sjogren's, add potential upside. For XACDURO, patient demand was strong, and hospital adoption continued to expand.

Performance was constrained by supply, and we expect those constraints may persist through the remainder of the year. That said, the underlying demand is encouraging, and local manufacturing, expected in 2027, should alleviate supply pressure and support meaningful growth and margin expansion over time.

Looking ahead, we see a strong set of commercial catalysts. KarXT launches in the second quarter and represents the first novel mechanism for schizophrenia in decades, a significant moment for the approximately 8 million patients living with this disease in China.

KarXT's inclusion in national treatment guidelines ahead of launch reflects strong clinical confidence in this therapy. Our focus this year is on physician education and market development, building a strong foundation for the brand.

We also anticipate potential regulatory approval for TIVDAK this year, and intend to leverage our existing ZEJULA infrastructure to drive commercial synergies and accelerate uptake. More broadly, our late-stage pipeline provides multiple additional growth opportunities in the region.

Recent positive Phase 3 readouts for povetacicept in IgAN and efgartigimod in thyroid eye disease add further depth to our long-term growth profile, and we see both as meaningful future contributors. Lastly, we are applying AI to sharpen commercial execution, from physician targeting and field force optimization to real-time competitive insights, enabling more agile and informed go-to-market decisions.

2026 is about execution: delivering on key launches, stabilizing the portfolio, and building momentum. With that, I will now pass the call over to Yajing to take us through our financial results.

Yajing?

Thank you, Josh. Our Quarter 1 results reflect the near-term dynamics just described.

First quarter total product revenue declined 6% year over year to $99.6 million, driven by lower ZEJULA sales, partially offset by continued growth from XACDURO and NUZYRA. While we expect total product revenue to improve sequentially over the next 9 months as underlying demand continues to build, we anticipate near-term pressure for 2026 full-year total product revenues, with a return to growth in 2027.

Turning now to our expenses. Our commitment to financial discipline is reflected in continued execution against our R&D and commercial priorities.

We will expand AI utilization from process automation to agentic execution to further improve cost efficiencies. R&D expenses for the first quarter increased 8% year over year, driven by increased license fees and clinical trial-related expenses, partially offset by lower personnel compensation expenses due to resource prioritization and efficiency efforts.

SG&A expenses increased slightly year over year, mainly due to higher general selling expenses. As a result, loss from operations increased by 23% for the quarter to $69.4 million.

We ended the quarter with a cash position of $761.3 million. Our regional business is commercially profitable.

Our global pipeline continues to progress steadily. Our focus this year remains on the strengthening the regional business, executing across global pipeline, and deploying capital thoughtfully to support both near-term launches and long-term growth drivers.

With a strong balance sheet, we are well-positioned to execute against these priorities. Operator, please open up the line for questions.

Hey guys, thanks for taking my questions. First question on the [ZL-1310?]

collaborations evaluating the combinations with DLL3 T-cell engagers. How do these facilitate your longer-term strategy, and are there other combinations and collaborations that make sense to explore?

Then second question on the commercial business in China, can you give us a sense for how to think about revenues over the course of the year? Thank you.

Hey, good morning, Jonathan. It's Josh.

Thank you. I'll ask Rafael to take the first one, and then Yajing can take the second.

Yes. Thanks for the question.

This combination, I spoke about the rationale of it during the prepared remarks, and the expectation is that we would get better efficacy in terms of responses, durability, and eventually better survival than with each agent alone. We're testing it in second line in tarlatamab-naive patients, tarlatamab-experienced patients, but importantly, also in first line.

Our first-line study will not include tarlatamab at the pivotal trial to begin with until we get more data, but if the data are positive, we may consider progressing this and developing it as a best-in-class regimen. It's really improving the baseline treatment of this disease with two really very active mechanisms.

Thanks, Rafael. Yajing?

Yes. Hi, Jonathan.

Thanks for the question. As I mentioned before, our revenue in the next 9 months, you're going to expect to see some sequential growth, but for the full-year revenue, we are going to continue to experience some short-term pressure.

We are seeing the return to growth in 2027.

Thanks, Yajing. Next question, operator?

Hey guys, thanks for taking our questions. This is Kyle Yang for Michael Yee from UBS.

Two for us. The first question is for your upcoming data readout for IL-13 and 31, what is the expectation for data, and how do you expect the dataset in healthy volunteers to derisk the asset?

When do we expect data from moderate-to-severe atopic dermatitis patients? The second question is that for your dataset in frontline small cell lung cancer in the second half, what is the expectation for that, and also what's good data?

How do you pick the go-forward regimen in terms of a doublet versus triplet? Thank you.

Thanks, Kyle. Go ahead, Rafael.

Yeah.

With the first question, in terms of expectations for 1503, the healthy volunteers data, I think, is going to be very useful. We actually have progressed the study quickly with dose cohorts, and we would be looking at safety obviously, pharmacokinetics to evaluate dosing interval, which we expect to be prolonged dosing, pharmacodynamics, such as fosfostatin and others, and anti-drug antibodies.

All of this, I think, will inform the basic parameters that will allow us to continue the development of the product. With regards to what to expect, obviously, it depends on how much data we have on atopic dermatitis, but we should have data on healthy volunteers by the end of the year and at least some of the cohorts with atopic dermatitis.

Our expectation is that we may publish this data before the end of the year. Then with regards to first line, the question was what do we consider as go forward.

That the chemotherapy plus checkpoint inhibitor, which would be the control of our study, has a PFS of about 5 months or so. Our response rate in second line with 1.6 milligrams per kilogram is in the order of 68%.

Obviously, there's still room for improvement there. We will be looking for higher response rates and also longer PFS than that we believe is clinically significant.

We plan to present this data towards the fall or so, and by then, we should have sufficient follow-up to really be able to evaluate that. We're currently planning to proceed with this study before the end of the year and in discussions with regulators.

Thank you.

Hey guys, thanks so much for taking the question. Just with the recent positive data for povetacicept in IgAN, what are the plans to submit in regional China, and just remind us, is there going to be any bridging work required?

Thanks so much.

Thanks, Anupam. Rafael?

We were very pleased to see the results of the RAINIER study, the really a good advance for IgAN. The filing of our partner has taken place, and we will discuss with CDE what the regulatory requirements for filing, but we expect that we will be able to proceed because we did include patients from China in the study, and a bridging study is not expected to be required.

As our partner, we would discuss with CDE our approach to an accelerated approval with this product.

Great. Thanks so much for taking our question.

Good morning. This is [unclear] on for Lee.

Question about ZL-1503, the bispecific antibody. It seems like data is going to come in the second half of this year.

There's a lot of bispecific antibody out there in AD. Would like to know what's your base assumption on the market differentiation for this drug and also your development strategy there.

Are you planning to run a Phase 2 trial, or are you potentially going to partner this out? Thank you.

Rafael, why don't you address that, and I can make a couple commercial comments.

Sure. In terms of differentiation, as I mentioned, I think long-term dosing is important, and we still have to evaluate how often that would be, but we expect that that would be the case for 1503.

In terms of activity, the key activity is obviously decreasing pruritus because our product inhibits the IL-31 receptor. We expect, using the numeric rating scale, that we would have a meaningful decrease in pruritus that's also occurring early on in the treatment, because I think that's really important and differentiating from other products.

The same for skin pain, which is something that affects the quality of life of patients. Of course, the main endpoint, which tends to be EASI-75, which you know what the benchmark out there is in the 40% range.

Surpassing these numbers would be, together with the extended dosing, something that we would consider very positive for us to move forward with Phase 2. As of the question of whether or not we plan to do that, the answer is yes.

We plan to do our Phase 2 study and evaluate these parameters as I mentioned before.

Okay.

I think just a comment, it's Josh. Obviously, it's a competitive class, but there's lots of room for differentiation, still very undertreated.

I think as Rafael said, what we know about patients is dosing convenience makes a difference, relief on itch and speed of onset are all important things that will elucidate over the course of the clinical development program. We're quite excited about the opportunity here.

Thanks.

Thank you.

Thank you, operator. I want to thank everyone for taking the time to join us on the call today.

We appreciate your support and look forward to updating you again after the second quarter of 2026. Operator, you may now disconnect this call.

Thank you.