Thank you for standing by, and welcome to the Guardant Health Q1 2021 Earnings Call. All lines are currently in a listen-only mode. After the speakers' presentation, there will a question-and-answer session. [Operator Instructions]. As a reminder, today's conference is being recorded. It is now my pleasure to hand the conference over to Carrie Mendivil of Investor Relations.

Thank you. Earlier today, Guardant Health released financial results for the quarter ended March 31, 2021. If you've not received this news release or if you'd like to be added to the company's distribution list, please send an email to Investors at guardanthealth.com. Joining me today from Guardant is Helmy Eltoukhy, Chief Executive Officer; AmirAli Talasaz, President; and Mike Bell, Chief Financial Officer. Before we begin, I'd like to remind you that management will make statements during this call that are forward-looking statements within the meaning of federal securities laws. These statements involve material risks and uncertainties that could cause actual results or events to materially differ from those anticipated. Additional information regarding these risks and uncertainties appears in the section entitled forward-looking statements in the press release Guardant issued today. For a more complete list and description, please see the Risk Factors section of the company's annual report on Form 10-K for the year ended December 31, 2020, and in its other filings with the Securities and Exchange Commission. This call will also include a discussion of certain financial measures that are not calculated in accordance with generally accepted accounting principles. Reconciliation to the most directly comparable GAAP financial measure may be found in today's earnings release submitted to the SEC. Except as required by law, Guardant disclaims any intention or obligation to update or revise any financial projections or forward-looking statements, whether because of new information, future events or otherwise. This conference call contains time-sensitive information and is accurate only as of the live broadcast, May 6, 2021. With that, I'd like to turn the call over to Helmy.

Thanks, Carrie. Good afternoon and thank you for joining our first quarter 2021 earnings call. Everything we do at Guardant is motivated by our commitment to serve patients. In line with our patient first commitment, I will start off our call today with a patient story. Six years ago, a 64-year-old man was diagnosed with metastatic colorectal adenocarcinoma and went through numerous therapy regimens and surgeries. In the spring of 2020, his cancer recurred and his new oncologist ordered a Guardant360 test. A BRAF V600 E mutation was identified. It is estimated that this mutation occurs in approximately 8% to 10% of colorectal cancers. By identifying this actionable mutation, he was able to begin treatment with a combination of targeted therapies of encorafenib plus binimetinib only recently approved by the FDA. Fortunately, the patient responded to the subject therapy. But as we know, tumors are constantly evolving. After about six months, the patient was showing signs of progression. His oncologist ordered another Guardant360 test with our standard panel that includes tumor mutational burden, or TMB. The second Guardant360 test identified the patient's tumor as TMB high. A few months earlier, the FDA had approved pembrolizumab for patients with TMB high tumors of 10 mutations per megabase and above. So this finding opened up another therapeutic avenue for this patient. This story highlights how genomic profiling using Guardant360 can keep up with the evolution of a tumor and identify ongoing therapeutic options. Turning to our first quarter performance. We started the year strong, with revenue growing 17% to approximately $79 million. I am really proud of our team for their continued hard work this quarter, which translated to solid growth in our clinical business as well as progress across our product pipeline. As expected, we continue to see residual COVID impact…

Thanks, Helmy. Our biopharma business as a whole is roughly back in line with the pre-COVID levels, and we are pleased with the progress we have made in Q1. Looking at biopharma samples, as expected, volumes for the first quarter was sequentially down from Q4 levels, but higher than the COVID trough we saw in Q2 and Q3 of 2020. Biopharma sample volumes were 3,522 tests for the first quarter, a decline of 33% from the prior year period. We continue to serve a growing number of biopharma customers with more than 70 partnerships currently underway. We are supporting an increasing number of studies, and we have a robust pipeline of discussions for future collaborations. However, while clinical trials are picking back up and growing patient volumes are still depressed compared to pre-COVID levels, we continue to impact both prospective and retrospective sample volumes. Looking at development services, we continue to see strong interest in our companion diagnostic business following FDA approval of Guardant360 in 2020. Development services revenue for the first quarter 2021 grew more than 100% to 14.9 million. Last week, we announced a strategic collaboration with Daiichi Sankyo to pursue regulatory approval and commercialization of Guardant360 CDx as a companion diagnostic for Enhertu, a HER2-directed antibody-drug conjugate, being studied in the treatment of patients with advanced metastatic non-small cell lung cancer. This further strengthens the importance of comprehensive profiling as more and more biomarkers are being pursued in this disease. We are also investing in our global companion diagnostic footprint as part of our mission to make CGP broadly available to patients around the world. To that end, we recently received our CIVB [ph] self certification for the EU, and submitted our initial PMDA filing in Japan. Our platform continues to generate data that further demonstrates the…

Thanks, AmirAli. Total revenue for the first quarter of 2021 was 78.7 million, up 17% from 67.5 million in the prior year quarter. This growth was driven by a year-over-year increase in both precision oncology testing revenue and development services and other revenue. Total precision oncology testing revenue for the first quarter was 63.7 million, a growth of 6% compared to $60.2 million in the prior year quarter. Precision oncology revenue from clinical testing in first quarter was 49.8 million, up 31% from $38 million for the prior year quarter. First quarter clinical test volume was 18,390, up 21% from the prior year quarter. The clinical test average selling price was 2,710 in the first quarter of 2021, up from 2,499 in the prior year period. First quarter 2021 clinical cash revenue of includes approximately $5 million recognized from cash collected for Guardant360 tests performed in prior periods. There are several factors that will impact the ASP of Guardant360 for the remainder of 2021. Firstly, we will have a positive impact from the new ADLT Medicare reimbursement rate of $5,000 for Guardant360 CDx. As a reminder, the $5,000 Medicare rate took effect on April 1, 2021 and will continue until January 1, 2022 at which time the rate will change to the median private payer rate. However, we continue to anticipate that the April 1 change to the ADLT billing code may have a short-term impact on the processing and payment of Guardant360 CDx by non-contracted private payers, which could offset the positive impact we receive from the increased ADLT Medicare reimbursement. In addition, we expect the impact on ASP caused by prior period cash collections to start to reduce in the second half of the year, as our revenue recognition becomes more weighted towards test performed in the current…

Thanks, Mike. Before closing, I want to thank our team for their incredible work to bring to fruition the vision we had when we founded Guardant of significantly improving outcomes across the entire continuum of cancer care. 2021 will be a pivotal year for us as we expand our product portfolio and invest across our business to open up the massive opportunity to transform cancer care for millions of patients. These new products also mark an important inflection point as we begin to transform Guardant from the leading liquid biopsy company to the leading cancer testing company. I’m so excited about what is ahead for Guardant and look forward to updating you on our progress. With that, we will now open it up to questions.

[Operator Instructions]. : :