Hello, ladies and gentlemen. Thank you for standing by. Welcome to Zai Lab's First Quarter 2022 Financial Results Conference Call. At this time, all participants are in a listen-only mode. Later, we will conduct a question-and-answer session and instructions will follow at that time. As a reminder, today's call is being recorded. It is now my pleasure to turn the floor over to Billy Cho, Chief Financial Officer of Zai Lab, who will make introductory comments.

Thank you, operator. Good morning, good evening and welcome, everyone. Zai Lab recently issued a press release providing the details of the company's financial results for the first quarter ended March 31, 2022, as well as product highlights and corporate updates. The press release is available in the Investor Relations section of the company's corporate website. Today's call will be led by Dr. Samantha Du, Zai Lab's Founder, Chairperson and Chief Executive Officer. She will be joined by Dr. Alan Sandler, President and Head of Global Development, Oncology, who will discuss advances with our oncology product candidate; Dr. Harald Reinhart, President and Head of Global Development, Neuroscience, Autoimmune and Infectious Diseases, who will speak about progress we have made in those three therapeutic areas; and I will discuss the performance of our market products and conclude with comments on our financial results. Additional executives will also be available to answer questions during the Q&A portion of the call. As a reminder, during today's call, Zai Lab will be making certain forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995, including our business plans and objectives and timing and success of our clinical trials, our sales and revenue forecasts for our products and product candidates, regulatory applications and commercial launches. These forward-looking statements are not guarantees of future performance and therefore you should not put undue reliance upon them. These statements are subject to numerous risks and uncertainties. Actual results could differ materially from what we expect due to various factors including those discussed in our SEC filings. At this time, it is my pleasure to turn the call over to Zai Lab's Founder, Chairperson and Chief Executive Officer, Dr. Samantha Du.

Thank you, Billy. Hello, everyone, and thank you all for joining us today. Our first-quarter results reflect Zai's solid foundation and track record of consistent execution and were marked by progress across the entire portfolio. To kick off today's quarter, I'd like to highlight the progress made on five proprietary platforms which consist of 11 internally developed products with global rights. Building upon last year's proof of concept achievement for ZL-1102, our anti-IL-17A Humabody for chronic plaque psoriasis, Zai recently unveiled preclinical data from four key oncology programs at the 2022 AACR Annual Meeting. With these assets just beginning to enter first-in-human and proof-of-concept clinical studies, we are in the exciting early days of demonstrating Zai's commitment to its in-house discovery and translational research. This proprietary pipeline complements the advancements within our later-stage partnered pipeline, which is expected to produce numerous pivotal study readouts throughout 2022. As you may recall, at the beginning of this year, we established 2022 strategic priorities that aim to position Zai to lead the next wave of biopharma innovation. I am pleased to say we continue to progress toward achieving these priorities, including progress toward filing the NDA for efgartigimod in China in mid-2022, initiation of a registrational study for bemarituzumab in first-line gastric cancer in Greater China, top line data readout for KarXT from its Phase 3 EMERGENT-2 trial by third quarter 2022, and continued investment in R&D to advance our proprietary pipeline with global rights, including moving ZL-1102 into full global development. Importantly, our commercial team continues to drive significant growth with our four marketed products in Greater China. Before turning the call over to Alan to discuss our oncology franchise in more detail, I'd like to make a brief comment on the ever-evolving COVID-19 situation in China. Zai continues to monitor the potential impact in certain regions in China. While COVID-19 did not have a significant impact on our business in the first quarter, it has presented access difficulties which we believe are likely to have a modest impact in the second quarter in China. Even so, we remain very confident in the underlying trends of our business despite the COVID-19 situation in China and the current macro and geopolitical headwinds. The fundamental drivers of value at Zai Lab are further strengthened by our expanding leadership team, global talent and our ever-growing pipeline, the steps we have taken to facilitate access to global capital markets, and our track record of consistent execution in bringing global first and best-in-class medicines to patients in China and beyond. We at Zai Lab remain committed to pursue our overall goal of improving human health worldwide and to build a leading global biopharmaceutical company. Now, I'd like to turn the call over to Dr. Alan Sandler.

Thank you, Samantha. Zai Lab's oncology franchise continued to make progress in the first quarter and we expect to have a busy and productive remainder of 2022. As Samantha mentioned, most recently, we unveiled initial preclinical data at the AACR Annual Meeting from key programs within our growing internally discovered oncology pipeline. In an oral presentation, the company presented data on our CCR8 targeted antibody ZL-1218. ZL-1218 is a novel antibody that targets the CCR8 receptor selectively expressed on resident Tregs in solid tumors. Zai highlighted the anti-tumor activity of ZL-1218 in an animal model, both as a single agent and in combination with anti-PD-1. Additional poster presentations at AACR included preclinical data from our CD47 targeting antibody ZL-1201, which is being studied in both advanced lymphomas and solid tumors, our Claudin 18.2-specific antibody ZL-1211, which has potential applications in gastric and pancreatic cancer, and our highly selective small molecule DNA-PK inhibitor ZL-2201, which has potential broad anti-cancer applications. In 2022, we plan to submit up to two INDs from our internal R&D platform, with a goal of filing at least one IND per year going forward. Our late-stage development programs in oncology continued to make progress on all fronts in the first quarter. For repotrectinib, we recently announced efficacy data from the Phase 1/2 TRIDENT-1 study revealing comparable results for ROS1 positive non-small cell lung cancer cohorts in China and global clinical trial sites. In TKI-naïve patients in China, the confirmed objective response rate was 91%, compared to 79% for global sites. In TKI-pretreated patients in China, the ORR was 36% in those treated with one prior line TKI compared to 36% for global sites. The ORR was 67% in those treated with one prior line TKI and one prior line platinum-based chemotherapy compared to 42% for global sites. The ORR was 50% in those treated with two prior lines TKI globally compared to 28% for global sites. Notably, all of those numbers represent confirmed responses. It is encouraging to see this comparative efficacy data analysis exploring clinical trial data from sites in China and globally for repotrectinib, a potentially best-in-class drug candidate for patients with ROS1 positive advanced non-small cell lung cancer. With over 800,000 newly diagnosed lung cancer patients every year in China, non-small cell lung cancer accounts for approximately 85% of cases and ROS1 rearrangements occur in 2% to 3% of those patients with advanced non-small cell lung cancer. The majority of these patients are diagnosed with advanced disease representing a significant unmet medical need. We will continue to work closely with Turning Point to advance this program to help support non-small cell lung cancer patients in China and around the world. Moving to ZEJULA, we presented positive results from the Phase 3 PRIME study of ZEJULA as maintenance therapy at the Society of Gynecologic Oncology annual meeting in March this year. In the PRIME study, the median progression-free survival was significantly longer for patients treated with niraparib compared to placebo, 24.8 months versus 8.3 months. For gBRCA mutated patients, median PFS was not reached, versus 10.8 months for the non-gBRCA mutated patients. Median PFS was 19.3 months versus 8.3 months. Overall, survival data were still immature, although there was a trend favoring niraparib at the data cut-off. We believe that the PRIME study further underscores the status of ZEJULA as the first and only PARP inhibitor approved globally as monotherapy for all-comer patients in the first-line maintenance treatment settings. Now, touching briefly on our later-stage pipeline, 2022 is poised to be another productive year with important pivotal data readouts, including top line data from the TTFields Phase 3 pivotal LUNAR clinical trial and the clinical data update from the Adagrasib Phase 2 registration-enabling non-small cell lung cancer cohort of the KRYSTAL-1 study. With an abundance of potentially best-in-class and first-in-class products, we are very excited about our oncology pipeline at Zai Lab. And now, I will turn the floor over to Dr. Harald Reinhart to discuss progress in our autoimmune and neuroscience therapeutic areas.

Thank you, Alan. I'll start with autoimmune diseases in efgartigimod or its marketed name VYVGART. In March 2022, Zai's partner, argenx, announced positive top line data from the Phase 3 ADAPT-SC study evaluating subcutaneous efgartigimod for the treatment of generalized myasthenia gravis, or gMG. Subcutaneous efgartigimod achieved the same amount of IgG reduction as the efgartigimod IV formulation in gMG patients, specifically subcutaneous efgartigimod demonstrated mean total IgG reductions of 66.4% from baseline at day 29 compared to 62.2% with IV efgartigimod. Results were consistent across the entire population, irrespective of acetylcholine receptor antibody status. Our partner, argenx, plans to submit a BLA to the FDA by the end of 2022. Just a few weeks ago, argenx announced interim results from the ongoing Phase 3 ADAPT+ study, a three-year extension study evaluating long-term safety, tolerability and efficacy of efgartigimod for the treatment of adults with gMG. These data suggest that long-term treatment with repeated cycles of efgartigimod provides undiminished benefits with each treatment course. The safety profile was consistent with what was observed in the pivotal program. Moving to ZL-1102, our topical IL-17 monoclonal antibody fragment. Last quarter, we reported that we were very excited to show skin penetration and early clinical benefit in a proof-of-concept trial in patients with chronic plaque psoriasis. As many of you know, the market opportunity for ZL-1102 is quite significant. Psoriasis affects approximately 125 million people worldwide, of which 80% to 90% suffer from chronic plaque psoriasis and 70% to 80% of these patients have mild to moderately severe disease. Facing strong rationale and patient need to develop a topical formulation with IL-17 directive therapy that works directly on the lesion and avoids systemic exposure and side effects. Current topical therapies provide limited efficacy or have safety issues with longer-term use. We are working hard to bring this innovative treatment option to patients in need as quickly as possible. In March 2022, we filed a patent for topical hydrogel, ramped up drug substance drug product production to support Phase 2 clinical trial activities and submitted a pre-IND meeting dossier to the FDA. We are on track to start a dose-finding Phase 2 trial of ZL-1102 in the second half of this year. Moving on to the neuroscience area. As you recall, last November, we entered into an agreement with Karuna Therapeutics for rights to KarXT in Greater China. KarXT is an oral investigational drug combination consisting of xanomeline, a muscarinic agonist that stimulates the M1/M4 receptors in the central nervous system and trospium, a muscarinic antagonist that reduces the incidence of peripheral GI side effects. In the Phase 2 EMERGENT-1 trial, KarXT demonstrated clinically meaningful and statistically significant improvements in the Positive and Negative Syndrome Score or PANSS total score. KarXT was well tolerated, much better than xanomeline alone. Our partner Karuna expects to report top line data from the pivotal Phase 3 study, also known as the EMERGENT-2 trial, in the third quarter of 2022. In addition, Karuna expects to initiate a study in Alzheimer's patients with psychosis in mid-2022. As part of a bridging program, the Zai team is getting ready to submit the clinical trial application for a pharmacokinetic study in China, designing a clinical trial program in collaboration with Chinese key opinion leaders and preparing for a meeting with the CDE in mid-2022. Now switching over to our two antibiotic programs. We will have major regulatory interactions for both of these this year. First, an update on Sulbactam-Durlobactam, our drug for multidrug-resistant Acinetobacter infections. Our partner, Entasis, has had a successful pre-NDA meeting with the FDA this spring and it is on course for U.S. NDA submission in mid-2022. Likewise, Zai will hold meetings with the CDE to discuss CMC filing requirements as there are subtle differences between the U.S. and China, and to respond to CDE queries from the last meeting. Our current plan is for a China submission in the fourth quarter of 2022. We will request breakthrough designation and ask for expedited review given the high unmet medical need for this important new drug in China. Omadacycline, NUZYRA, was just launched in China with our China partner. On the commercial front, we hope to see the same strong healthcare provider and patient uptake in China that has been seen in the United States. Zai will meet with CDE later this year to discuss post-approval studies, which we are currently designing with expert input to meet both regulatory expectations and to support marketing efforts. And now, Billy will speak about progress with our commercial products and financial results.

I forgot to mention we are facing multiple actions to facilitate access to global capital markets and we expect Zai Lab to continue to have strong liquidity in the future. In April, we announced the engagement of KPMG LLP, a U.S. auditor as our independent registered public accounting firm. KPMG will be engaged to audit the annual consolidated financial statements of Zai Lab filed with the U.S. SEC and our internal controls over financial reporting for the fiscal year ending December 31, 2022. The engagement of KPMG is a natural outgrowth of our continued evolution into a global biopharmaceutical company. Consistent with our globalization strategy, we view our global shareholder base as key for future success and to achieving our vision of improving human health worldwide. KPMG's engagement facilitates continued global liquidity for our shareholders through our NASDAQ and Hong Kong Stock Exchange listings. The transition to a U.S. auditor like KPMG also fits well with our existing and growing presence in the United States. In addition, we have announced our plan to pursue voluntary conversion to dual primary listing on the Main Board to the Hong Kong Stock Exchange recently. Becoming a dual primary listed company will enable us to be eligible for Stock Connect, which is a key channel by which investors in mainland China can invest in stocks traded on the Hong Kong Stock Exchange. We want to provide all investors with robust liquidity for our ADSs traded on NASDAQ as well as ordinary shares traded on the Hong Kong Stock Exchange. This follows from our share split of our ordinary shares in issue, which became effective March 30, 2022. Moving to our commercial performance. Our strong commercial execution continues to drive robust revenue growth in our four marketed products: ZEJULA, Optune, QINLOCK, and NUZYRA. ZEJULA continued to perform well. Building on the news from year end 2021 that the first line ovarian cancer indication was included in the NRDL. With this favorable reimbursement decision and ZEJULA's unique label for ovarian cancer patients regardless of biomarker status, we are seeing a promising trend of gaining market share for ZEJULA in the first three months of this year, and we continue to expect it to achieve a leadership position among therapies available to treat ovarian cancer no later than next year. In addition, as of March 31, 2022, ZEJULA was listed in over 1,500 hospitals in China, providing a strong foundation for post-NRDL performance. Similarly, we continue to achieve solid growth in Optune. In the first quarter, Optune continued to be one of the top three treatments reimbursed. As for QINLOCK, we are committed to establishing it as a standard treatment for fourth-line GIST, which sees over 7,000 new patients every year in China and growing. As of March 31, 2022, Optune and QINLOCK are covered by 37 and 58 municipal or provincial supplemental insurance plans in China, respectively. As we noted last year, NUZYRA was successfully launched in China in December. It is a novel antibiotic with both oral and intravenous formulations for the treatment of community-acquired bacterial pneumonia and acute bacterial skin and skin structure infections. NUZYRA was approved as a Category 1 innovative drug and is locally manufactured in China. We believe NUZYRA is a potential best-in-class tetracycline with demonstrated efficacy comparable to moxifloxacin in CABP and to linezolid in ABSSSI. With significant unmet needs for broad-spectrum antibiotics addressing MDR infections with a favorable safety profile, we expect to seek NRDL inclusion for both indications this year to benefit many more patients in need. Now I will discuss first-quarter financial results. Total revenues for the first quarter of 2022 were $46.7 million, up from $20.1 million for the same period in 2021. As mentioned, we are very pleased with the successful launches and sales trajectory of our market products. With many more product launches to come, our commercial platform over time is expected to generate strong continued growth and considerable operating leverage. ZEJULA sales for the first quarter of 2022 were $29.6 million. Over the same period in 2021, ZEJULA sales were $12.6 million. Optune sales for the first quarter were $12.8 million. Over the same period in 2021, Optune sales were $7.1 million. QINLOCK sales for the first quarter were $3 million. Over the same period in 2021, QINLOCK sales were $0.4 million. NUZYRA sales for the first quarter were $0.7 million. Research and development expenses were $53.9 million for the first quarter of 2022 compared to $203.9 million for the same period in 2021. The decrease in R&D expenses was primarily due to no upfront payment for new licensing agreements, partially offset by increased expenses related to ongoing and newly initiated late-stage clinical trials and higher payroll and payroll-related expenses from increased R&D headcount. Excluding upfront payments for new licensing agreements, core R&D expenses were $53.9 million for the first quarter in 2022 compared to $41.6 million for the same period in 2021. Selling, general and administrative expenses were $57 million for the first quarter of 2022 compared to $35.8 million in the same period in 2021. The increase was primarily due to payroll and payroll-related expenses from increased commercial and general and administrative headcount, as Zai Lab continued to expand and invest in its commercial operations in China in anticipation of substantial top-line growth over the next few years. Zai Lab reported a net loss of $82.4 million for the first quarter of 2022, or a loss per share attributable to common stockholders of $0.09, compared to a net loss of $232.9 million, or a loss per share attributable to common stockholders of $0.26 for the same period in 2021. As of March 31, 2022, cash and cash equivalents, short-term investments, and restricted cash totaled $1.31 billion compared to $1.41 million as of December 31, 2021. We would now like to turn the call back over to the operator to open up the line for questions.

Thank you. We would now like to open the line for questions. Our first question comes from Michael Yee from Jefferies. Please go ahead with your question.

Thank you. Good morning. I appreciate the update. We had two questions. One was a big picture question and one was a pipeline question. From a big picture perspective, and obviously investors are watching afar but a bit concerned about the various challenges in China, maybe you could just talk a little bit about some of the commercial dynamics and whether there's any impact due to lockdowns and access to hospitals, and particularly with respect to enrolling clinical trials. A lot of different companies are saying different things. So if you could give us a snapshot of what's going on there that would be helpful? And the pipeline question is you affirmed in your press release that you are planning to submit efgartigimod to China FDA in the middle of this year. Did you actually meet with the FDA and confirm that that's okay, or are you still in discussions? If you could shed some light there, that would be great. Thank you.

Hi, Mike. Thanks for your questions. I'll take the first one and give the second one to either Samantha or Harald. So in terms of the COVID situation, we've been operating under a COVID environment for well over two years now and have developed protocols and procedures, which have been in place to minimize impact throughout this time. Now as you may have heard from prepared remarks, there are some challenges in the second quarter, in particular in Shanghai. So we're continuing to monitor very closely, but I would like to report that as of the most recent statistic, the number of new cases are less than 5%. It may be even less than 4% of the peak. And yesterday, there were zero cases found in the community. So most importantly, overall, at this particular point in time, we do not feel the need to make any changes to our previously communicated execution goals for this year, including all of our clinical development and regulatory milestones. In terms of the global programs and strategies that we have, there's no impact there, and all of our programs are on track, including initiating a global Phase 2 trial of IL-17 program called ZL-1102 in the second half of this year.

Great to hear on that. And efgartigimod?

Yes. Hi. Thank you so much for the question on efgartigimod and the regulatory pathway forward. Yes, we have indeed plans to meet with not the FDA but the CDE in the middle of this year, and we have already submitted a dossier to them in follow-up to a communication we had with them last year. You may recall we mentioned it in our press releases that we had a very good meeting with them about what would be the ingredients they expect in our dossier. In the meantime, since that meeting last year, a lot of things have happened, including the results of our PK studies in China came through. More importantly, even the Japan approval for efgartigimod, which is broad label for this drug. So we are now ready and awaiting a response from the CDE on our proposed plans going forward. When that meeting will be exactly we don’t know, but it will hopefully happen in the middle of this year, and that will dictate what we do subsequently.

Got it. Thank you very much.

Thank you. Our next question comes from Yigal from Citigroup. Please ask your question.

Hi, Samantha and Billy and team. Thank you for taking the questions. I have one for you, Billy, just regarding the news last month where you announced KPMG will be engaged as an independent registered accounting firm. Just wondering, are there any other operational or technical steps that you need to gain compliance with HFCAA at this point, or is the inspection by the PCAOB the only step? And if inspection is the only step left, could you just clarify what sign KPMG needs to demonstrate in this inspection to satisfy the regulators? Thank you.

Yes. Hi, Yigal. Thanks for your question. You're right. On April 21, we did release a press release and filed an 8-K where the Audit Committee or our Board appointed KPMG U.S. as an auditor for the purposes of finding the financial statements with the SEC in Hong Kong for that matter. As many of you know, an accountant from the U.S. is subject to inspection by the PCAOB. Therefore, consistent with what we've been stating and also filing in our Qs last year and our most recent K, we don't expect any interruption to our NASDAQ listing. We expect, with very high confidence, that we will comply with HFCAA and we do fully expect to be off the list in the next 10-K cycle.

Okay, got you. And then maybe a question for Samantha or Alan, shifting to the pipeline regarding the in-house topical IL-17. I think you've indicated that Zai is meeting with FDA soon to design a comprehensive Phase 2 program, which, as you noted in the call, is expected to be a global multicenter study in chronic plaque psoriasis. So first question is operationally, have you had that engagement yet with FDA? And if so, what were the takeaways? And then secondly, looking further down the road since 1102, obviously a wholly-owned program, I'm just curious what are your thoughts on whether you would launch this product beyond China? Obviously, this is a highly appealing product for the U.S., European and Japanese markets. Additionally, given the recent addition of Josh Smiley to the team, his experience at Lilly and scaling pharma businesses, I think could prove very useful in building an international franchise for 1102. So if you could offer your thoughts there, that'd be great. Thank you.

Yes, this is I guess a question for me. IL-17, 1102 is indeed now going and getting ready for a Phase 2 study in the U.S. This is something we need to still discuss with the FDA. To your question, we did not have this meeting yet, but we have submitted the dossier. We will hear back from them and adjust accordingly. We still believe that we can start this study, a Phase 2 study, multicenter as you say, placebo-controlled and all the rest, by the end of this year. As far as your question goes about the global reach, maybe I can hand over to others. But I do believe this has indeed attractiveness in many regions, and we will discuss this in-house and with our marketing people in great detail how to stagger our approach. Over to you, Billy.

Samantha, please?

Yes. Thank you, Yigal. As we announced, Josh will be the COO of Zai Lab beginning August 1. You are correct that Josh has full experience on a global basis. I have no doubt he will be a key contributing member of our global organization. In terms of where his involvement comes in, he has the capability to do it in-house, but also can support our international initiatives.

Thank you very much.

Thank you, Yigal.

Thank you. Our next question comes from Anupam Rama from JPMorgan. Please ask your questions.

Hi, guys. Thanks so much for taking the question. Maybe following up on one of the prior questions, can you give us a sense of the strategies that you have in place for your sales team to continue to engage with physicians in the region, given the COVID-19 restrictions we've talked about on this call in certain regions? Thanks so much.

Hi, Anupam. Yes, I'm happy to provide some examples. As mentioned earlier, we have developed protocols and procedures for working in this environment. One example is creating a digital solution to promote and engage with the medical community in a compliant manner. We had to build that. Another example involves managing prescription needs for patients, particularly in light of recent flare-ups in China over the past two years. We've implemented strategies to potentially increase prescriptions at different facilities and established the necessary protocols and systems for that. I hope this gives you a better understanding of what we’re discussing.

Thanks so much for taking my question.

Thank you. Our next question comes from Jonathan Chang from SVB Securities. Please ask your questions.

Hi, guys. Thanks for taking my questions. First question, with the recent volatility in the markets, can you discuss how your strategy around business development, especially with smaller and earlier stage companies, has changed, if at all?

Jon, do you want to take this one?

Yes, sure. Hi, Jonathan. Thanks for the question. We are, as always, focused on continually building our pipeline, world-class assets with the balance of both internal as well as external efforts. In the current environment, we also see a lot of interesting and promising opportunities, which is very good from a BD perspective. If you sort of look at, more than half of the U.S. biotech companies today are trading under cash. So we do see potential opportunities to pick up great assets at good prices. At the same time, we continue to have very strong interest from Western companies, as they think about China, how to leverage China to access the second largest pharmaceutical market, but also to accelerate their global timeline. We have a continued good source of those types of opportunities as well. As always, I think we'll be very selective when it comes to any BD opportunity. We have a very high bar for bringing assets. I'll also acknowledge that today, our share price is severely dislocated. So any opportunity will have an even higher bar to meet in today's market and environment. We certainly think about BD in light of this context.

Got it. Thanks for taking that question. And then I guess second question for me. Can you provide some color on the NUZYRA sales trends since first line NRDL inclusion?

Hi, Jonathan. We are not publicly sharing script data or market share data, though we have that information internally. Some data will be available throughout our quarterly results. However, you will notice a significant increase in market share starting from the third quarter of last year, through the fourth quarter and into this year. ZEJULA has seen substantial year-over-year growth, particularly in the fourth and first quarters. Even in the first quarter, which included energy implementation and seasonally low performance in China due to holidays, we managed to counterbalance a 23% price discount with strong revenue. It's important to note that gaining nationwide listings and prescriptions isn't instantaneous; it requires a concerted effort to get on hospital lists and manage prescriptions. Our commercial team deserves credit for the strong performance in the first quarter, and we are pleased with that outcome. Much of this success stems from ZEJULA being included in the first line on the NRDL. You can expect to see a similar trend in the upcoming quarters, along with expected gains in market share.

Got it. Thanks for taking my questions.

Thank you. Our next question comes from Ziyi Chen from Goldman Sachs. Please ask your question.

Thank you for taking my questions. Just one simple question on the cash burn. So first quarter, cash burn has been significantly below previous quarters. And so that's a pretty light quarter. There was no licensing fees in the first quarter. What will that guide us to think about the overall budgeting for the rest of the year, and particularly facing the toughest funding environment are there possible ways, strategies to extend the cash runway? If you have to manage your budget, how will that affect your BD commitment? Thank you.

Ziyi, I'm happy to take this one. First of all, we have a very productive and efficient platform by design and strategy. I think that historically and more recently, we've been giving guidance on BD costs versus core R&D. But it's not really BD versus R&D. It's really integrated. By being able to build a portfolio with much higher product success and a development and regulatory strategy that plugs into a global trial, it really is by design in terms of efficiency. So you're seeing some of that. But yes, overall, in terms of cash runway commentary, even with BD deals, we're going to have runway to the end of 2024. There could be a future where BD activity results in capital inflow. Today, we have $1.3 billion in cash. Our cash burn for the first quarter was $97 million, down from $160 million in Q4 of last year and also down from $171 million year-over-year. It’s difficult to give guidance on upfront payment for the year, but it won't be at 2021 levels. You should look at the historical three-year range. Over '19, '20, and '21, those numbers were $59 million, $108 million, $384 million, respectively, and I already told you that it's not going to be $384 million.

Got it. Thank you, Billy.

Thank you. Our next question comes from Yang Huang from Credit Suisse. Please ask your question.

Thanks for giving me an opportunity to ask. I have two quick ones. First is kind of a quick follow-up on COVID. Given the lockdown in some of the Chinese cities in the first quarter and the second quarter, I wonder do we see any drug stocking and dynamic change in the first quarter and also in the second quarter this year compared to last year? That's my first question.

Hi, Yang. In terms of inventory to channel stocking strategy, there's no material change. There could be some kind of nuanced incremental activity given what's going on, but nothing material. So our strategy there is quite comparable, quite consistent.

Okay, I see. And then my second question is on SG&A expense. Compared to the same period last year, we still see a significant increase in SG&A which is due to our headcount increase. I'm wondering during this difficult period, what is our overall plan for headcount to increase for the whole year? And what's the rationale behind it?

Yes. So SG&A, you're right, Yang, in terms of year-over-year, so first quarter compared to first quarter last year, our SG&A was not up 59%. But it was actually down Q4 to Q1. What that means is that at Q1 of last year, we were still in build mode, mainly in our commercial team as well. But this year, we don't expect that—we don’t need to expand our commercial presence significantly. We already have 950 employees, and we're going to be able to ramp up revenue while not adding a material number of employees. It could just be incremental at most. So that's operating leverage kicking in. SG&A will be up overall year-over-year, but it will not be close to the level from first quarter of last year to first quarter of this year for the reasons I stated.

Okay, got it. Thanks a lot.

All right. Thank you. We have reached the end of the question-and-answer session. I will turn the call back to Zai Lab's CEO, Samantha Du, for closing remarks.

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. Operator, you may now disconnect this call.

Thank you. That does conclude our conference for today. Thank you for participating. You may all disconnect.