CareDx (CDNA) 10-Q 5 May 21 2021 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2021	May 03, 2021
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-36536
Entity Registrant Name	CAREDX, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-3316839
Entity Address, Address Line One	1 Tower Place
Entity Address, City or Town	South San Francisco
Entity Address, State or Province	CA
Entity Address, Postal Zip Code	94080
City Area Code	415
Local Phone Number	287-2300
Title of 12(b) Security	Common Stock, par value $0.001 per share
Trading Symbol	CDNA
Security Exchange Name	NASDAQ
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		52,053,956
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	Q1
Entity Central Index Key	0001217234
Current Fiscal Year End Date	--12-31

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 309,324	$ 134,669
Marketable securities	64,963	90,034
Accounts receivable	43,361	34,624
Inventory	13,721	10,012
Prepaid and other current assets	7,332	3,758
Total current assets	438,701	273,097
Property and equipment, net	11,398	10,704
Operating leases right-of-use assets	18,289	15,228
Intangible assets, net	45,457	44,355
Goodwill	26,109	23,857
Restricted cash	269	270
Other assets	1,000	1,000
Total assets	541,223	368,511
Current liabilities:
Accounts payable	11,597	9,653
Accrued compensation	10,495	18,466
Accrued and other liabilities	23,638	20,602
Refund liability - CMS advance payment (Note 1)	0	20,496
Total current liabilities	45,730	69,217
Deferred tax liability	945	1,299
Common stock warrant liability	420	447
Deferred payments for intangible assets	3,640	3,560
Operating lease liability, less current portion	18,462	16,069
Other liabilities	480	240
Total liabilities	69,677	90,832
Commitments and contingencies (Note 9)
Stockholders’ equity:
Preferred stock: $0.001 par value; 10,000,000 shares authorized at March 31, 2021 and December 31, 2020; no shares issued and outstanding at March 31, 2021 and December 31, 2020	0	0
Common stock: $0.001 par value; 100,000,000 shares authorized at March 31, 2021 and December 31, 2020; 51,939,121 shares and 49,441,166 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	51	49
Additional paid-in capital	828,308	632,253
Accumulated other comprehensive loss	(3,599)	(2,096)
Accumulated deficit	(353,214)	(352,527)
Total stockholders’ equity	471,546	277,679
Total liabilities and stockholders’ equity	$ 541,223	$ 368,511

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)	10,000,000	10,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, par value (in usd per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	51,939,121	49,441,166
Common stock, shares outstanding (in shares)	51,939,121	49,441,166

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue:
Total revenue	$ 67,400	$ 38,380
Operating expenses:
Research and development	16,004	10,013
Sales and marketing	15,452	11,723
General and administrative	15,223	10,003
Total operating expenses	68,258	44,131
Loss from operations	(858)	(5,751)
Other income (expense):
Interest income, net	126	96
Change in estimated fair value of common stock warrant liability	27	(405)
Other expense, net	(245)	(63)
Total other expense	(92)	(372)
Loss before income taxes	(950)	(6,123)
Income tax benefit	263	300
Net loss	$ (687)	$ (5,823)
Net loss per share (Note 3):
Basic (in dollars per share)	$ (0.01)	$ (0.14)
Diluted (in dollars per share)	$ (0.01)	$ (0.14)
Weighted-average shares used to compute net loss per share:
Basic (in shares)	51,181,160	42,823,427
Diluted (in shares)	51,181,160	42,823,427
Testing services
Revenue:
Total revenue	$ 59,281	$ 31,442
Operating expenses:
Cost of goods and services	16,483	7,928
Product
Revenue:
Total revenue	5,778	4,695
Operating expenses:
Cost of goods and services	3,647	3,199
Digital And Other
Revenue:
Total revenue	2,341	2,243
Operating expenses:
Cost of goods and services	$ 1,449	$ 1,265

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Statement of Comprehensive Income [Abstract]
Net loss	$ (687)	$ (5,823)
Other comprehensive loss:
Foreign currency translation adjustments, net of tax	(1,503)	(1,705)
Net comprehensive loss	$ (2,190)	$ (7,528)

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Beginning balance (in shares) at Dec. 31, 2019		42,498,430
Beginning balance at Dec. 31, 2019	$ 99,000	$ 42	$ 437,976	$ (5,205)	$ (333,813)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common stock under ESPP (in shares)		38,147
Issuance of common stock under ESPP	699		699
RSU settlements, net of shares withheld (in shares)		139,552
RSU settlements, net of shares withheld	(1,507)		(1,507)
Issuance of common stock for services (in shares)		3,091
Issuance of common stock for services	66		66
Issuance of common stock for cash upon exercise of stock options (in shares)		44,861
Issuance of common stock for cash upon exercise of stock options	155		155
Issuance of common stock for cash upon exercise of warrants (in shares)		295,466
Issuance of common stock for cash upon exercise of warrants	6,299		6,299
Employee stock-based compensation expense	4,200		4,200
Foreign currency translation adjustment	(1,705)			(1,705)
Net loss	(5,823)				(5,823)
Ending balance (in shares) at Mar. 31, 2020		43,019,547
Ending balance at Mar. 31, 2020	101,384	$ 42	447,888	(6,910)	(339,636)
Beginning balance (in shares) at Dec. 31, 2020		49,441,166
Beginning balance at Dec. 31, 2020	277,679	$ 49	632,253	(2,096)	(352,527)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Issuance of common shares, net of commissions and offering costs (in shares)		2,211,538
Issuance of common shares, net of commissions and offering costs	188,755	$ 2	188,753
Issuance of common stock under ESPP (in shares)		24,052
Issuance of common stock under ESPP	838		838
RSU settlements, net of shares withheld (in shares)		121,447
RSU settlements, net of shares withheld	(2,313)		(2,313)
Issuance of common stock for services (in shares)		1,339
Issuance of common stock for services	$ 96		96
Issuance of common stock for cash upon exercise of stock options (in shares)	139,579	139,579
Issuance of common stock for cash upon exercise of stock options	$ 2,193		2,193
Employee stock-based compensation expense	6,488		6,488
Foreign currency translation adjustment	(1,503)			(1,503)
Net loss	(687)				(687)
Ending balance (in shares) at Mar. 31, 2021		51,939,121
Ending balance at Mar. 31, 2021	$ 471,546	$ 51	$ 828,308	$ (3,599)	$ (353,214)

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Stockholders' Equity (Parenthetical) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Public Offering
Common stock, commissions and offering costs	$ 12,495

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Operating activities:
Net loss	$ (687)	$ (5,823)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Stock-based compensation	6,547	4,259
Revaluation of common stock warrant liability to estimated fair value	(27)	405
Depreciation and amortization	1,950	1,619
Amortization of right-of-use assets	677	612
Revaluation of contingent consideration to estimated fair value	(44)	190
Changes in operating assets and liabilities:
Accounts receivable	(8,755)	2,346
Inventory	(4,056)	(1,343)
Prepaid and other assets	(3,628)	(545)
Operating leases liabilities, net	(320)	(344)
Accounts payable	1,496	1,757
Accrued compensation	(7,662)	(5,914)
Accrued and other liabilities	1,661	48
Refund liability - CMS advance payment	(20,496)	0
Change in deferred taxes	(286)	(322)
Net cash used in operating activities	(33,630)	(3,055)
Investing activities:
Acquisition of business, net of cash acquired	(3,543)	0
Acquisition of intangible assets	(1,200)	0
Maturities of marketable securities	25,072	0
Additions of capital expenditures, net	(1,250)	(1,704)
Net cash provided by (used in) investing activities	19,079	(1,704)
Financing activities:
Proceeds from issuance of common stock under employee stock purchase plan	667	358
Taxes paid related to net share settlement of restricted stock units	(2,313)	(1,507)
Proceeds from exercise of warrants	0	304
Proceeds from exercise of stock options	2,193	155
Principal payments on finance lease obligations	(34)	(45)
Net cash provided by (used in) financing activities	189,228	(735)
Effect of exchange rate changes on cash and cash equivalents	(23)	(552)
Net increase (decrease) in cash, cash equivalents and restricted cash	174,654	(6,046)
Cash, cash equivalents, and restricted cash at beginning of period	134,939	38,479
Cash, cash equivalents, and restricted cash at end of period	309,593	32,433
Public Offering
Financing activities:
Proceeds from issuance of common shares in public equity offering, net of issuance costs paid	$ 188,715	$ 0

Organization and Description of

Organization and Description of Business	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Description of Business	ORGANIZATION AND DESCRIPTION OF BUSINESS CareDx, Inc. (“CareDx” or the “Company”), together with its subsidiaries, is a leading precision medicine company focused on the discovery, development and commercialization of clinically differentiated, high-value diagnostic solutions for transplant patients and caregivers. The Company’s headquarters are in South San Francisco, California. The primary operations are in Brisbane, California; Omaha, Nebraska; Fremantle, Australia; and Stockholm, Sweden. The Company’s commercially available testing services consist of AlloSure® Kidney, which is a donor-derived cell-free DNA (“dd-cfDNA”) solution for kidney transplant patients, AlloMap® Heart, which is a gene expression solution for heart transplant patients, and AlloSure® Heart, a dd-cfDNA test which can identify underlying cell injury leading to organ rejection. The Company has initiated several clinical studies to generate data on its existing and planned future testing services. In April 2020, the Company announced its first biopharma research partnership for AlloCell, a surveillance solution that monitors the level of engraftment and persistence of allogeneic cells for patients who have received cell therapy transplants. The Company also offers high-quality products that increase the chance of successful transplants by facilitating a better match between a donor and a recipient of stem cells and organs. In 2019, the Company began providing digital solutions to transplant centers following the acquisitions of Ottr Complete Transplant Management (“Ottr, Inc.”) and XynManagement, Inc. (“XynManagement”), as well as the acquisition of TransChart LLC (“TransChart”). Testing Services AlloSure Kidney has been a covered service for Medicare beneficiaries since October 2017. The Medicare reimbursement rate for AlloSure Kidney is currently $2,841 . AlloSure Kidney has received positive coverage decisions from Blue Cross Blue Shield (“BCBS”) of South Carolina, BCBS of Kansas City and Capital Health, and is reimbursed by other private payers on a case-by-case basis. AlloMap Heart has been a covered service for Medicare beneficiaries since January 2006. The Medicare reimbursement rate for AlloMap Heart is currently $3,240 . AlloMap Heart has also received positive coverage decisions for reimbursement from many of the largest U.S. private payers, including Aetna, Cigna, Health Care Services Corporation, Humana, Kaiser Foundation Health Plan, Inc. and UnitedHealthcare. In October 2020, AlloSure Heart received a final Palmetto MolDx Medicare coverage decision for AlloSure Heart. In November 2020 , Noridian Healthcare Solutions, the Company's Medicare Administrative contractor, issued a parallel coverage policy granting coverage when used in conjunction with AlloMap Heart, which became effective in December 2020. The Medicare reimbursement rate for AlloSure Heart is currently $2,753. Clinical Studies In January 2018, the Company initiated the Kidney Allograft Outcomes AlloSure Kidney Registry study (“K-OAR”), to develop additional data on the clinical utility of AlloSure Kidney for surveillance of kidney transplant recipients. K-OAR is a multicenter, non-blinded, prospective observational cohort study which has enrolled more than 1,700 renal transplant patients who will receive AlloSure Kidney long-term surveillance. In September 2018, the Company initiated the Surveillance HeartCare™ Outcomes Registry (“SHORE”). SHORE is a prospective, multi-center, observational registry of patients receiving HeartCare for surveillance. HeartCare combines the gene expression profiling technology of AlloMap Heart with the dd-cfDNA analysis of AlloSure® Heart in one surveillance solution. In February 2019, AlloSure® Lung became available for lung transplant patients through a compassionate use program while the test is undergoing further studies. In June 2020, the Company submitted an AlloSure Lung application to the Palmetto MolDx Technical Assessment program seeking coverage and reimbursement for Medicare beneficiaries. In September 2019, the Company announced the commencement of the Outcomes of KidneyCare on Renal Allografts (“OKRA”) study, which is an extension of K-OAR. OKRA is a prospective, multi-center, observational, registry of patients receiving KidneyCare for surveillance. KidneyCare combines the dd-cfDNA analysis of AlloSure Kidney with the gene expression profiling technology of AlloMap Kidney and the predictive artificial intelligence technology of KidneyCare iBox developing a multimodality surveillance solution. The Company has not yet made any applications to private payers for reimbursement coverage of AlloMap Kidney or KidneyCare iBox. Enrollment for OKRA was negatively affected by the COVID-19 restrictions during the year 2020, and the study had been delayed by six months; however, the collection of samples are at normal levels as a result of the introduction of RemoTraC. Following the successful implementation of RemoTraC, OKRA is planned to be fully enrolled by the end of 2021. The patients will then be followed for a period of three years with the output of the study due in 2024. Products The Company’s suite of AlloSeq products are commercial next generation sequencing (“NGS”)-based kitted solutions that the Company has developed as a result of its license agreement with Illumina, Inc. (“Illumina”). These products include: AlloSeq™ Tx, a high-resolution Human Leukocyte Antigen (“HLA”) typing solution, AlloSeq™ cfDNA, a surveillance solution designed to measure dd-cfDNA in blood to detect active rejection in transplant recipients, and AlloSeq™ HCT, a solution for chimerism testing for stem cell transplant recipients. The Company's other HLA typing products include: TruSight HLA, a NGS-based high resolution typing solution; Olerup SSP®, based on the sequence specific primer (“SSP”) technology; and QTYPE®, which uses real-time polymerase chain reaction (“PCR”) methodology, to perform HLA typing at a low to intermediate resolution for samples that require a fast turnaround time. In March 2021, the Company acquired BFS Molecular S.R.L. (“BFS Molecular”), a software company focused on NGS-based patient testing solutions. BFS Molecular brings extensive software and algorithm development capabilities for NGS transplant surveillance products. Digital and Other Following the acquisitions of both Ottr, Inc. and XynManagement, the Company is a leading provider of transplant patient tracking software (“Ottr software”), as well as of transplant quality tracking and waitlist management solutions. Ottr software provides comprehensive solutions for transplant patient management and enables integration with electronic medical record (“EMR”) systems providing patient surveillance management tools and outcomes data to transplant centers. XynManagement provides two unique solutions, XynQAPI software (“XynQAPI”) and XynCare. XynQAPI simplifies transplant quality tracking and Scientific Registry of Transplant Recipients reporting. XynCare includes a team of transplant assistants who maintain regular contact with patients on the waitlist to help prepare for their transplant and maintain eligibility. In September 2020, the Company launched AlloCare, a mobile app that provides a patient-centric resource for transplant recipients to manage medication adherence, coordinate with Patient Care Managers for AlloSure scheduling and measure health metrics. In January 2021, the Company acquired TransChart LLC for cash. TransChart provides EMR software to hospitals throughout the U.S. to care for patients who have or may need an organ transplant. As part of its acquisition of TransChart in January 2021, the Company acquired Tx Connect, a cloud-based service that allows nephrologists and dialysis centers to electronically submit referrals to transplant programs, closely follow and assist patients through the transplant waitlist process, and ultimately, through transplantation. COVID-19 Pandemic On January 30, 2020, the World Health Organization (the “WHO”) announced a global health emergency because of a new strain of coronavirus (“COVID-19”) originating in Wuhan, China and the risks to the international community as the virus spread globally beyond its point of origin. In March 2020, the WHO classified the COVID-19 outbreak as a pandemic, based on the rapid increase in exposure globally. The full impact of the COVID-19 pandemic, including the impact associated with preventative and precautionary measures that the Company, other businesses and governments are taking, continues to evolve as of the date of this report. As such, it is uncertain as to the full magnitude that the pandemic will have on the Company, but the pandemic may materially affect the Company's financial condition, liquidity and future results of operations. In the final weeks of March and during April 2020, with hospitals increasingly caring for COVID-19 patients, hospital administrators chose to limit or even defer, non-emergency procedures. Immunosuppressed transplant patients either self-prescribed or were asked to avoid transplant centers and caregiver visits to reduce the risk of contracting COVID-19. As a result, with transplant surveillance visits down, the Company experienced a slowdown in testing services volumes in the final weeks of March and during April 2020. As a response to the COVID-19 pandemic, and to enable immune-compromised transplant patients to continue to have their blood drawn, in late March 2020, the Company launched RemoTraC, a remote home-based blood draw solution using mobile phlebotomy for AlloSure and AlloMap surveillance tests, as well as for other standard monitoring tests. To date, more than 200 transplant centers can offer RemoTraC to their patients and over 7,000 kidney, heart and lung transplant patients have enrolled. Based on existing and new relationships with partners, the Company has established a nationwide network of more than 10,000 mobile phlebotomists. Following the introduction of RemoTraC and with the easing of stay-at-home restrictions and the opening up of many hospitals to non-COVID-19 patients, the Company’s testing services volumes returned to levels consistent with those experienced immediately prior to the COVID-19 pandemic, an d through March 31, 2021, volumes continued to be at or above those levels since May 2020. In spite of the resurgence of COVID-19 infection rates, which resulted in increased stay-at-home and renewed travel restrictions, the Company did not experience a decrease in testing services volumes. The Company’s product business experienced a reduction in forecasted sales volume throughout the second and third quarters of 2020, as it was unable to undertake onsite discussions and demonstrations of its recently launched NGS products, including AlloSeq Tx 17, which was a warded CE mark authorization in May 2020. The Company's product business maintained normal sales volumes during the fourth quarter of 2020 and continued to maintain normal sales volumes through the first quarter of 2021. The Company is maintaining its testing, manufacturing, and distribution facilities while implementing specific protocols to reduce contact among employees. In areas where COVID-19 impacts healthcare operations, the Company’s field-based sales and clinical support teams are supporting providers through telephone and online platforms. In August 2020, the state of California released revised criteria for loosening and tightening restrictions on certain activities on generally a county-by-county basis. Under the updated executive orders, San Mateo County, where the Company's laboratory and headquarters are located, continues to be subject to certain restrictions. These orders and others may be further modified, amended and adopted depending upon the COVID-19 transmission rates in our county and state, as well as other factors. In addition, the Company has created a COVID-19 task force that is responsible for crisis decision making, employee communications, enforcing pre-arrival temperature checking, daily health check-ins and enhanced safety training/protocols in its offices for employees that do not work from home. Liquidity and Capital Resources The Company has incurred significant losses and negative cash flows from operations since its inception and had an accumulated deficit of $353.2 million at March 31, 2021. As of March 31, 2021, the Company had cash, cash equivalents and marketable securities of $374.3 million. CMS Accelerated and Advance Payment Program for Medicare Providers On March 27, 2020 the U.S. government enacted the Coronavirus Aid, Relief, and Economic Security Act ( the “ CARES Act”). Pursuant to the CARES Act, the Centers for Medicare & Medicaid Services ( “ CMS”) expanded its Accelerated and Advance Payment Program in order to increase cash flow to providers of services and suppliers impacted by the COVID-19 pandemic. CMS is authorized to provide accelerated or advance payments during the period of the public health emergency to any Medicare provider who submitted a request to the appropriate Medicare Administrative Contractor and met the required qualifications. During April 2020, the Company received an advance payment from CMS of approximately $20.5 million, and recorded the payment as Deferred revenue - CMS advance payment on the Company's condensed consolidated balance sheet. During December 2020, the Company reassessed the Deferred revenue - CMS advance payment and repaid the entire amount in January 2021. The Company recorded the amount as Refund liability - CMS advance payment on the condensed consolidated balance sheet as of December 31, 2020. Refer to Note 8, Balance Sheet Components, for further explanation. CARES Act Provider Relief Fund for Medicare Providers Pursuant to the CARES Act, the U.S. Department of Health & Human Services ( “HHS ”) distributed an initial tranche of $30.0 billion in funds to healthcare providers that received Medicare fee-for-service ( “ FFS”) reimbursements in 2019. These payments to healthcare providers are not loans and will not be required to be repaid. As a condition to receiving these payments, providers must agree to certain terms and conditions and submit sufficient documentation demonstrating that the funds are being used for healthcare-related expenses or lost revenue attributable to the COVID-19 pandemic. Due to the recent enactment of legislation and absence of definitive guidance, there is a high degree of uncertainty around the CARES Act’s implementation and the Company continues to assess the impact on its business. Furthermore, HHS has indicated that it, along with the Office of Inspector General, will be closely monitoring and auditing providers to ensure that recipients comply with the terms and conditions of relief programs and to prevent fraud and abuse. All providers will be subject to civil and criminal penalties for any deliberate omissions, misrepresentations or falsifications of any information given to HHS. Providers will be distributed a portion of the initial $30.0 billion of funds based on their share of total Medicare FFS reimbursements made by the U.S. in 2019. During April 2020, the Company received a payment of approximately $4.8 million representing its portion of the initial tranche of funds, recorded in other income (expense), net on the condensed consolidated statements of operations. The Company is complying with the key terms and provisions of the CARES Act Provider Relief Fund, which includes, among other things, the requirement that the Company maintain appropriate records and cost documentation. The Company has registered with HHS to submit financial data indicating the use of the funds the Company received pursuant to the CARES Act Provider Relief Fund. The Company will be notified by HHS when the Provider Relief Fund Reporting Portal is open for reporting on the use of Provider Relief Fund payments. Underwritten Public Offering of Common Stock On June 15, 2020, the Company sold 4,492,187 shares of common stock (which included shares sold pursuant to the underwriters’ full exercise of an overallotment option granted to the underwriters in connection with the offering) through an underwritten public offering at a price of $32.00 per share for aggregate net proceeds of approximately $134.6 million. Public Offering of Common Stock On January 25, 2021, the Company sold 1,923,077 shares of its common stock through an underwritten public offering at a public offering price of $91.00 per share. The net proceeds to the Company from the offering were approximately $164.0 million, after deducting underwriting discounts and commissions and offering expenses. On February 11, 2021, the Company sold 288,461 shares of its common stock pursuant to the full exercise of the overallotment option granted to the underwriters in connection with the offering. The net proceeds to the Company from the full exercise of the underwriters' overallotment option were approximately $24.7 million.

Summary of Significant Accounti

Summary of Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES The significant accounting policies and estimates used in preparation of the unaudited condensed consolidated financial statements are described in the Company’s audited consolidated financial statements as of and for the year ended December 31, 2020, and the notes thereto, which are included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020. Material changes to the significant accounting policies previously disclosed in the Company’s Annual Report on Form 10-K for the year ended December 31, 2020 are reflected below. Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”), and follow the requirements of the Securities and Exchange Commission (the “SEC”) for interim reporting. As permitted under those rules, certain notes and other financial information that are normally required by U.S. GAAP can be condensed or omitted. These unaudited condensed consolidated financial statements have been prepared on the same basis as the Company’s annual consolidated financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments that are necessary for a fair statement of the Company’s financial information. The condensed consolidated balance sheet as of December 31, 2020 has been derived from audited consolidated financial statements as of that date but does not include all of the financial information required by U.S. GAAP for complete financial statements. Operating results for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021. Correction to Presentation The presentation of certain prior period amounts within the accompanying condensed consolidated statements of operations have been corrected, including creating separate line items for the presentation of cost of testing services, cost of product and cost of digital and other, which were previously reported, in aggregate, in total cost of revenue of $12.4 million for the three months ended March 31, 2020. These corrections had no effect on loss from operations, loss before taxes, or net loss. The Company evaluated these corrections, considering both qualitative and quantitative factors, and concluded they are immaterial to previously issued financial statements. Use of Estimates The preparation of unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities and the reported amounts of revenues and expenses in the unaudited condensed consolidated financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to transaction price estimates used for testing services revenue; standalone fair value of digital revenue performance obligations; accrued expenses for clinical studies; inventory valuation; the fair value of issued common stock warrants and embedded derivatives; the fair value of assets and liabilities acquired in a business combination or an assets acquisition (including identifiable intangible assets acquired); the fair value of contingent consideration recorded in connection with a business combination; the grant date fair value assumptions used to estimate stock-based compensation expense; income taxes; impairment of long-lived assets and indefinite-lived assets (including goodwill); and legal contingencies. Actual results could differ from those estimates. Concentrations of Credit Risk and Other Risks and Uncertainties For the three months ended March 31, 2021 and 2020 , approximately 60% and 53%, respectively, of total revenue was derived from Medicare. As of March 31, 2021 and December 31, 2020, approximately 31% and 28%, respectively, of accounts receivable was due from Medicare. No other payer or customer represented more than 10% of accounts receivable on either March 31, 2021 or December 31, 2020. Marketable Securities The Company considers all highly liquid investments in securities with a maturity of greater than three months at the time of purchase to be marketable securities. As of March 31, 2021, the Company’s marketable securities consisted of corporate debt securities with maturities of greater th an three months but less than twelve months at the time of purchase. Thes e marketable securities are classified as current assets on the condensed consolidated balance sheet. The Company classifies its marketable securities as held-to-maturity at the time of purchase and reevaluates such designation at each balance sheet date. The Company has the positive intent and ability to hold these marketable securities to maturity. Marketable securities are carried at amortized cost and are adjusted for amortization of premiums and accretion of discounts to maturity, which is included in interest income (expense), net on the condensed consolidated statements of operations. Realized gains and losses and declines in value judged to be other-than-temporary, if any, on marketable securities are included in interest income (expense), net. The cost of securities sold will be determined using specific identification. Leases Effective January 1, 2019, the Company adopted Accounting Standard Codification (“ASC”) Topic 842, Leases using the optional transition method and applied the standard only to leases that existed at that date. The Company determines if an arrangement is or contains a lease at contract inception. A right-of-use (“ROU”) asset, representing the underlying asset during the lease term, and a lease liability, representing the payment obligation arising from the lease, are recognized on the condensed consolidated balance sheet at lease commencement based on the present value of the payment obligation. For operating leases, expense is recognized on a straight-line basis over the lease term. For finance leases, interest expense on the lease liability is recognized using the effective interest method and amortization of the ROU asset is recognized on a straight-line basis over the shorter of the estimated useful life of the asset or the lease term. Short-term leases with an initial term of 12 months or less are not recorded on the balance sheet. The present value of lease payments is determined by using the interest rate implicit in the lease, if that rate is readily determinable; otherwise, the Company uses its incremental borrowing rate. The incremental borrowing rate is determined by using the rate of interest that the Company would pay to borrow on a collateralized basis an amount equal to the lease payments for a similar term and in a similar economic environment. As of March 31, 2021, the Company’s leases had remaining terms of 0.21 years to 7.92 years, some of which include options to extend the lease term. Recent Accounting Pronouncements In October 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2020-10, Codification Improvements, which contains amendments that improve the consistency of the ASC by including all disclosure guidance in the appropriate Disclosure Section (Section 50). The FASB provided transition guidance for all the amendments in this ASU. The amendments in Sections B and C (Section A has been removed) of this ASU are effective for annual periods beginning after December 15, 2020 for public business entities. Early application of the amendments in this ASU is permitted for public business entities for any annual or interim period for which financial statements have not been issued. The amendments in this ASU should be applied retrospectively. The Company adopted the standard on January 1, 2021. The adoption of the new standard did not have an impact on the Company's condensed consolidated financial statements and disclosures.

Net Loss Per Share

Net Loss Per Share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Net Loss Per Share	NET LOSS PER SHARE Basic and diluted net loss per share have been computed by dividing the net loss by the weighted-average number of common shares outstanding during the period, without consideration of common share equivalents as their effect would have been antidilutive. The following tables set forth the computation of the Company’s basic and diluted net loss per share (in thousands, except shares and per share data): Three Months Ended March 31, 2021 2020 Numerator: Net loss used to compute basic and diluted net loss per share $ (687) $ (5,823) Denominator: Weighted-average shares used to compute basic and diluted net loss per share 51,181,160 42,823,427 Net loss per share: Basic and diluted $ (0.01) $ (0.14) The following potentially dilutive securities have been excluded from diluted net loss per share as of March 31, 2021 and 2020 because their effect would be antidilutive: Three Months Ended March 31, 2021 2020 Shares of common stock subject to outstanding options 2,592,281 2,845,862 Shares of common stock subject to outstanding common stock warrants 6,264 49,006 Restricted stock units 1,853,419 1,502,012 Total common stock equivalents 4,451,964 4,396,880

Fair Value Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	FAIR VALUE MEASUREMENTS The Company records its financial assets and liabilities at fair value. The carrying amounts of certain financial instruments of the Company, including cash and cash equivalents, prepaid expenses and other current assets, accounts payable and accrued liabilities, approximate fair value due to their relatively short maturities. Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability (an exit price) in an orderly transaction between market participants at the reporting date. The accounting guidance establishes a three-tiered hierarchy, which prioritizes the inputs used in the valuation methodologies in measuring fair value as follows: • Level 1: Inputs that include quoted prices in active markets for identical assets and liabilities. • Level 2: Inputs other than Level 1 that are observable, either directly or indirectly, such as quoted prices for similar assets or liabilities, quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. • Level 3: Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The following table sets forth the Company’s financial assets and liabilities, measured at fair value on a recurring basis, as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 Fair Value Measured Using (Level 1) (Level 2) (Level 3) Total Balance Assets Money market funds $ 280,099 $ — $ — $ 280,099 Liabilities Common stock warrant liability $ — $ — $ 420 $ 420 December 31, 2020 Fair Value Measured Using (Level 1) (Level 2) (Level 3) Total Balance Assets Money market funds $ 85,797 $ — $ — $ 85,797 Liabilities Common stock warrant liability $ — $ — $ 447 $ 447 The following table presents the issuances, exercises, changes in fair value and reclassifications of the Company’s Level 3 financial instruments that are measured at fair value on a recurring basis (in thousands): (Level 3) Common Stock Warrant Liability Balance as of December 31, 2020 $ 447 Exercise of warrants — Change in estimated fair value (27) Balance as of March 31, 2021 $ 420 As of March 31, 2021, the Company had one investment in convertible preferred shares carried at cost. See Note 7, “Goodwill and Intangible Assets”. In the event the Company had to calculate the fair value of this investment, it would be based on Level 3 inputs. This investment is not considered material to the Company's condensed consolidated financial statements. In determining fair value, the Company uses various valuation approaches within the fair value measurement framework. The valuation methodologies used for the Company’s instruments measured at fair value and their classification in the valuation hierarchy are summarized below: • Money market funds – Investments in money market funds are classified within Level 1. Money market funds are valued at the closing price reported by the fund sponsor from an actively traded exchange. At March 31, 2021 and December 31, 2020, money market funds were included as cash and cash equivalents in the condensed consolidated balance sheets. • Marketable securities —Investments in marketable securities are classified within Level 2. The securities are valued using third-party pricing sources. The pricing services utilize industry standard valuation models, including both income and market-based approaches, for which all significant inputs are observable, either directly or indirectly. • Common stock warrant liability – The Company utilizes a binomial-lattice pricing model (the “Monte Carlo Simulation Model”) that involves a market condition simulation to estimate the fair value of the warrants. The application of the Monte Carlo Simulation Model requires the use of a number of complex assumptions, including the Company’s stock price, expected life of the warrants, stock price volatility determined from the Company’s historical stock prices and stock prices of peer companies in the diagnostics industry, and risk-free rates based on the implied yield currently available in the U.S. Treasury zero-coupon issues with a remaining term equal to the expected life of the warrants. Increases (decreases) in the assumptions discussed above result in a directionally similar impact to the fair value of the common stock warrant liability. Common Stock Warrant Liability Valuation Assumptions: March 31, 2021 December 31, 2020 Private Placement Common Stock Warrant Liability Stock Price $ 68.09 $ 72.45 Exercise Price $ 1.12 $ 1.12 Remaining term (in years) 2.04 2.28 Volatility 72.00 % 73.00 % Risk-free interest rate 0.17 % 0.14 %

Cash and Marketable Securities

Cash and Marketable Securities	3 Months Ended
	Mar. 31, 2021
Cash and Cash Equivalents [Abstract]
Cash and Marketable Securities	CASH AND MARKETABLE SECURITIES Cash, Cash Equivalents and Restricted Cash A reconciliation of cash, cash equivalents, and restricted cash reported within the condensed consolidated balance sheets to the amount reported within the condensed consolidated statements of cash flows is shown in the table below (in thousands): March 31, 2021 December 31, 2020 March 31, 2020 December 31, 2019 Cash and cash equivalents $ 309,324 $ 134,669 $ 32,191 $ 38,223 Restricted cash 269 270 242 256 Total cash, cash equivalents, and restricted cash at the end of the period $ 309,593 $ 134,939 $ 32,433 $ 38,479 Marketable Securities All marketable securities were considered held-to-maturity at March 31, 2021 and December 31, 2020. As of March 31, 2021 and December 31, 2020, some of the Company’s marketable securities were in an unrealized loss position. The Company determined that it had the positive intent and ability to hold until maturity all marketable securities that have been in a continuous loss position, thus there was no recognition of any other-than-temporary impairment as of March 31, 2021 and December 31, 2020. All marketable securities with unrealized losses as of each balance sheet date have been in a loss position for less than twelve months. The amortized cost, gross unrealized holding losses, and fair value of the Company’s marketable securities by major security type at each balance sheet date are summarized in the table below (in thousands): March 31, 2021 Amortized Cost Unrealized Holding Losses Fair Value Short-term marketable securities: Corporate debt securities $ 64,963 $ (66) $ 64,897 Total short-term marketable securities $ 64,963 $ (66) $ 64,897 December 31, 2020 Amortized Cost Unrealized Holding Losses Fair Value Short-term marketable securities: Corporate debt securities $ 90,034 $ (136) $ 89,898 Total short-term marketable securities $ 90,034 $ (136) $ 89,898 Contractual maturities of the short-term marketable securities all mature within one year as of March 31, 2021.

Business Combinations

Business Combinations	3 Months Ended
	Mar. 31, 2021
Business Combinations [Abstract]
Business Combinations	BUSINESS COMBINATIONS TransChart LLC In January 2021, the Company acquired TransChart for cash. TransChart provides EMR software to hospitals throughout the U.S. to care for patients who have or may need an organ transplant. TransChart builds on the Company's digital offerings, which include Ottr, Inc. transplant electronic medical record software and XynQAPI transplant quality management solutions. As a result of the acquisition, the Company recognized goodwill of $2.3 million and intangible assets of $2.0 million. The pro forma impact of the TransChart acquisition is not material, and the results of operations of the acquisition have been included in the Company's condensed consolidated statements of operations from the respective acquisition date.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	GOODWILL AND INTANGIBLE ASSETS Goodwill Goodwill is recorded when the purchase price of an acquisition exceeds the fair value of the net tangible and identified intangible assets acquired. Goodwill is tested annually for impairment at the reporting unit level during the fourth quarter or earlier upon the occurrence of certain events or substantive changes in circumstances. There were no indicators of impairment in the three months ended March 31, 2021. The balance of the Company's goodwill as of March 31, 2021 and December 31, 2020 was $26.1 million and $23.9 million, respectively . Intangible Assets The following tables present details of the Company’s intangible assets as of March 31, 2021 ($ in thousands): March 31, 2021 Gross Carrying Amount Accumulated Amortization Foreign Currency Translation Net Carrying Amount Weighted Average Remaining Useful Life Intangible assets with finite lives: Acquired and developed technology $ 33,569 $ (9,692) $ (1,262) $ 22,615 9.0 Customer relationships 19,308 (5,015) (953) 13,340 10.6 Commercialization rights 8,079 (1,241) — 6,838 8.4 Trademarks and tradenames 2,380 (856) (110) 1,414 9.6 Total intangible assets with finite lives $ 63,336 $ (16,804) $ (2,325) $ 44,207 Acquired in-process technology 1,250 — — 1,250 Total intangible assets $ 64,586 $ (16,804) $ (2,325) $ 45,457 The following table presents details of the Company’s intangible assets as of December 31, 2020 ($ in thousands): December 31, 2020 Gross Carrying Amount Accumulated Amortization Foreign Currency Translation Net Carrying Amount Weighted Average Remaining Useful Life Intangible assets with finite lives: Acquired and developed technology $ 31,209 $ (8,991) $ (725) $ 21,493 9.1 Customer relationships 18,168 (4,684) (449) 13,035 10.9 Commercialization rights 8,079 (1,039) — 7,040 8.7 Trademarks and tradenames 2,360 (804) (19) 1,537 9.9 Total intangible assets with finite lives $ 59,816 $ (15,518) $ (1,193) $ 43,105 Acquired in-process technology 1,250 — — 1,250 Total intangible assets $ 61,066 $ (15,518) $ (1,193) $ 44,355 Acquisition of Intangible Assets In June 2020, the Company commercially launched AlloSeq HCT, a NGS solution for chimerism testing for stem cell transplant recipients. This technology has the potential to provide better sensitivity and data analysis compared to current solutions on the market. AlloSeq HCT is included in Acquired and developed technology as of December 31, 2020 and March 31, 2021. Amortization of Intangible Assets Amortization expense was $1.3 million and $1.1 million for the three months ended March 31, 2021 and 2020, respectively. For the three months ended March 31, 2021, expenses of $0.3 million, $0.5 million, $0.1 million and $0.4 million were amortized to cost of testing services, cost of product, cost of digital and other and sales and marketing, respectively. For the three months ended March 31, 2020, expenses of $0.3 million, $0.4 million, $0.1 million and $0.3 million were amortized to cost of testing services, cost of product, cost of digital and other and sales and marketing, respectively. The following table summarizes the Company’s estimated future amortization expense of intangible assets with finite lives as of March 31, 2021 (in thousands): Years Ending December 31, Cost of Testing Services Cost of Product Cost of Digital and Other Sales and Marketing Total Remainder of 2021 $ 987 $ 1,430 $ 323 $ 1,083 $ 3,823 2022 1,316 1,906 431 1,437 5,090 2023 1,316 1,906 431 1,427 5,080 2024 1,316 1,906 431 1,427 5,080 2025 1,316 1,906 431 1,427 5,080 Thereafter 5,457 5,020 1,622 7,955 20,054 Total future amortization expense $ 11,708 $ 14,074 $ 3,669 $ 14,756 $ 44,207

Balance Sheet Components

Balance Sheet Components	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Balance Sheet Components	BALANCE SHEET COMPONENTS Inventory Inventory consisted of the following (in thousands): March 31, 2021 December 31, 2020 Finished goods $ 2,416 $ 1,702 Work in progress 3,210 2,936 Raw materials 8,095 5,374 Total inventory $ 13,721 $ 10,012 Accrued and Other Liabilities Accrued and other liabilities consisted of the following (in thousands): March 31, 2021 December 31, 2020 Deferred revenue $ 3,522 $ 3,530 Clinical studies 7,023 6,733 Deferred payments for intangible assets 2,000 2,000 Short-term lease liability 3,126 2,033 Test sample processing fees 505 416 Accrued royalty 1,342 1,072 Contingent consideration 694 738 Professional fees 2,393 1,529 Other accrued expenses 3,033 2,551 Total accrued and other liabilities $ 23,638 $ 20,602 CMS Accelerated and Advance Payment Program for Medicare Providers On March 27, 2020, the U.S. government enacted the CARES Act. Pursuant to the CARES Act, CMS expanded its Accelerated and Advance Payment Program in order to increase cash flow to providers of services and suppliers impacted by the COVID-19 pandemic. CMS was authorized to provide accelerated or advance payments during the period of the public health emergency to any Medicare provider who submitted a request to the appropriate Medicare Administrative Contractor and met the required qualifications. During April 2020, the Company received an advance payment from CMS of approximately $20.5 million and recorded the payment as Deferred revenue - CMS advance payment on the Company's condensed consolidated balance sheet. During December 2020, the Company reassessed the Deferred revenue - CMS advance payment and repaid the entire amount in January 2021. The Company recorded the amount as Refund liability - CMS advance payment on the condensed consolidated balance sheet as of December 31, 2020.

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Leases The Company leases its operating and office facilities for various terms under long-term, non-cancelable operating lease agreements in South San Francisco, California; Brisbane, California; West Chester, Pennsylvania; Fremantle, Australia; and Stockholm, Sweden. The Company also leases equipment under finance lease agreements. On January 2, 2020, the Company executed the second amendment to the operating lease agreement for the building located at Brisbane, California. The building is mainly utilized for laboratory operations and research and development. The lease was extended for a period of eight years and two months starting on January 1, 2021. The Company had determined that the amendment constituted a lease modification effective January 1, 2020. At the inception of the lease modification, the ROU asset increased by $13.0 million. The Company's facility leases expire at various dates through 2029. In the normal course of business, it is expected that these leases will be renewed or replaced by leases on other properties. As of March 31, 2021, the carrying value of the ROU asset was $18.3 million. The related current and non-current liabilities as of March 31, 2021 were $3.1 million and $18.5 million, respectively. The current and non-current lease liabilities are included in accrued and other current liabilities and operating lease liability, less current portion, respectively, in the condensed consolidated balance sheets. The following table summarizes the lease cost for the three months ended March 31, 2021 and 2020 (in thousands): Three Months Ended March 31, 2021 2020 Operating lease cost $ 1,205 $ 1,119 Finance lease cost 30 53 Total lease cost $ 1,235 $ 1,172 Finance lease cost includes interest from the lease liability and amortization of the ROU asset. Other information: Weighted-average remaining lease term - Operating leases (in years) 6.78 Weighted-average remaining lease term - Finance leases (in years) 0.22 Weighted-average discount rate - Operating leases (%) 10.5% Weighted-average discount rate - Finance leases (%) 4.8% Maturities of operating and finance lease liabilities as of March 31, 2021 are as follows (in thousands): Year Ending December 31, Finance Leases Operating Leases Remainder of 2021 $ 34 $ 3,718 2022 — 4,971 2023 — 3,724 2024 — 3,846 2025 — 3,988 Thereafter — 10,256 Total lease payments 34 30,503 Less imputed interest — 8,915 Present value of future minimum lease payments $ 34 21,588 Less operating lease liability, current portion 3,126 Operating lease liability, long-term portion $ 18,462 The current portion of obligations under finance leases is included in accrued and other liabilities, and the long-term portion of finance leases is included in other liabilities within the condensed consolidated balance sheets. Royalty Commitments The Board of Trustees of the Leland Stanford Junior University (“Stanford”) In June 2014, the Company entered into a license agreement with Stanford (the “Stanford License”), which granted the Company an exclusive license to a patent relating to the diagnosis of rejection in organ transplant recipients using dd-cfDNA. Under the terms of the Stanford License, the Company is required to pay an annual license maintenance fee, six milestone payments and royalties in the low single digits of net sales of products incorporating the licensed technology. Illumina On May 4, 2018, the Company entered into a license agreement with Illumina (the “Illumina Agreement”). The Illumina Agreement requires the Company to pay royalties in the mid-single to low-double digits on sales of products covered by the Illumina Agreement. Cibiltech Commitments Pursuant to that certain license and commercialization agreement that the Company entered into with Cibiltech SAS (“Cibiltech”) effective April 30, 2019, the Company will share an agreed-upon percentage of revenue with Cibiltech, if and when revenues are generated from KidneyCare iBox. Other Commitments Pursuant to the Illumina Agreement, the Company has agreed to minimum purchase commitments of finished products and raw materials from Illumina through 2023. Litigation and Indemnification Obligations In response to the Company's false advertising suit filed against Natera Inc. (“Natera”), on April 10, 2019, Natera filed a counterclaim against the Company on February 18, 2020, in the U.S. District Court for the District of Delaware (the “Court”) alleging the Company made false and misleading claims about the performance capabilities of AlloSure. The suit seeks injunctive relief and unspecified monetary relief. On September 30, 2020, Natera requested leave of Court to amend its counterclaims to include additional allegations regarding purportedly false claims the Company made with respect to AlloSure, and the Court granted Natera’s request. Trial is currently scheduled to begin on July 26, 2021. In addition, in response to the Company's patent infringement suit filed against Natera on March 26, 2019, Natera filed suit against the Company on January 13, 2020 in the Court alleging, among other things, that AlloSure infringes Natera’s U.S. Patent 10,526,658. On March 25, 2020, Natera filed an amendment to the suit alleging, among other things, that AlloSure also infringes Natera’s U.S. Patent 10,597,724. The suit seeks a judgment that the Company has infringed Natera’s patents, an order preliminarily and permanently enjoining the Company from any further infringement of such patents and unspecified damages. The Company intends to defend both of these matters vigorously, and believes that the Company has good and substantial defenses to the claims alleged in the suits, but there is no guarantee that the Company will prevail. The Company has not recorded any liabilities for these suits. From time to time, the Company may become involved in litigation and other legal actions. The Company estimates the range of liability related to any pending litigation where the amount and range of loss can be estimated. The Company records its best estimate of a loss when the loss is considered probable. Where a liability is probable and there is a range of estimated loss with no best estimate in the range, the Company records a charge equal to at least the minimum estimated liability for a loss contingency when both of the following conditions are met: (i) information available prior to issuance of the condensed consolidated financial statements indicates that it is probable that a liability had been incurred at the date of the condensed consolidated financial statements and (ii) the range of loss can be reasonably estimated.

401(K) Plan

401(K) Plan	3 Months Ended
	Mar. 31, 2021
Retirement Benefits [Abstract]
401(K) Plan	401(K) PLANThe Company sponsors a 401(k) defined contribution plan covering all U.S. employees under the Internal Revenue Code of 1986, as amended. Employee contributions are voluntary and are determined on an individual basis subject to the maximum allowable under federal tax regulations. The Company incurred expenses related to contributions to the plan of $0.5 million and $0.3 million for the three months ended March 31, 2021 and 2020, respectively.

Warrants

Warrants	3 Months Ended
	Mar. 31, 2021
Warrants and Rights Note Disclosure [Abstract]
Warrants	WARRANTS The Company issues common stock warrants in connection with debt or equity financings to lenders, placement agents and investors. Issued warrants are considered standalone financial instruments and the terms of each warrant are analyzed for equity or liability classification in accordance with U.S. GAAP. Warrants that are classified as liabilities usually have various features that would require net-cash settlement by the Company. Warrants that are not liabilities, derivatives and/or meet the exception criteria are classified as equity. Warrants liabilities are remeasured at fair value at each period end with changes in fair value recorded in the condensed consolidated statements of operations until expired or exercised. Warrants that are classified as equity are valued at their relative fair value on the date of issuance, recorded in additional paid in capital and not remeasured. In the three months ended March 31, 2021, there were no warrants exercised to purchase shares of common stock for cash proceeds. In the three months ended March 31, 2020, warrants to purchase approximately 272,000 shares of common stock were exercised for cash payments of $0.3 million. During the three months ended March 31, 2020, a warrant to purchase approximately 34,000 shares of common stock was exercised on a cashless basis and approximately 24,000 shares were issued pursuant to the exercise. As of March 31, 2021, outstanding warrants to purchase common stock were: Classified as Original Term Exercise Price Number of Shares Underlying Warrants Original issue date: April 2016 Liability 7 years $ 1.12 6,264 6,264

Stock Incentive Plans

Stock Incentive Plans	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Stock Incentive Plans	STOCK INCENTIVE PLANS Stock Options and Restricted Stock Units (“RSU”) The following table summarizes option and RSU activity under the Company’s 2014 Equity Incentive Plan, 2016 Inducement Equity Incentive Plan, and 2019 Inducement Equity Incentive Plan, and related information: Shares Stock Weighted- Number of Weighted- Balance—December 31, 2020 672,968 2,670,398 $ 21.92 1,884,866 $ 28.42 Additional shares authorized 1,977,647 — — — — Common stock awards for services (1,339) — — — — RSUs granted (246,379) — — 246,379 82.62 RSUs vested — — — (207,881) 24.06 Options granted (127,925) 127,925 81.06 — — Options exercised — (139,579) 13.99 — — Repurchase of common stock under employee incentive plans 74,434 — — — — RSUs forfeited 69,945 — — (69,945) 29.32 Options forfeited 66,213 (66,213) 25.70 — — Options expired 250 (250) 22.59 — — Balance—March 31, 2021 2,485,814 2,592,281 $ 25.17 1,853,419 $ 36.14 The total intrinsic value of options exercised was $9.1 million and $0.7 million for the three months ended March 31, 2021 and 2020, respectively. As of March 31, 2021, the total intrinsic value of outstanding RSUs was approximately $126.2 million and there were $50.7 million of unrecognized compensation costs related to RSUs, which are expected to be recognized over a weighted-average period of 1.91 years. Options outstanding that have vested and are expected to vest at March 31, 2021 are as follows: Number of Shares Issued Weighted-Average Weighted-Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Vested 1,045 $ 16.09 6.54 $ 54,318 Expected to vest 1,398 31.91 8.68 52,508 Total 2,443 $ 106,826 The aggregate intrinsic value is calculated as the difference between the exercise price of the underlying stock options and the fair value of the Company’s common stock at March 31, 2021 for stock options that were in-the-money. The total fair value of options that vested during the three months ended March 31, 2021 was $2.7 million. As of March 31, 2021, there were approximately $25.2 million of unrecognized compensation costs related to stock options, which are expected to be recognized over a weighted-average period of 2.89 years. 2014 Employee Stock Purchase Plan The Company has an Employee Stock Purchase Plan (the “ESPP”), under which employees can purchase shares of its common stock based on a percentage of their compensation, but not greater than 15% of their respective earnings; provided, however, an eligible employee’s right to purchase shares of the Company’s common stock may not accrue at a rate which exceeds $25,000 of the fair market value of such shares for each calendar year in which such rights are outstanding. The ESPP has consecutive offering periods of approximately six months in length. The purchase price per share must be equal to the lower of 85% of the fair value of the common stock on the first day of the offering period or on the exercise date. During the offering period in 2020 that ended on December 31, 2020, 24,052 shares were purchased for aggregate proceeds of $0.8 million from the issuance of shares, which occurred on January 4, 2021. Valuation Assumptions The estimated fair values of employee stock options and ESPP shares were estimated using the Black-Scholes option pricing model based on the following weighted average assumptions: Three Months Ended March 31, 2021 2020 Employee stock options Expected term (in years) 6.0 6.0 Expected volatility 77.69% 74.00% Risk-free interest rate 0.68% 1.35% Expected dividend yield —% —% Employee stock purchase plan Expected term (in years) 0.5 0.5 Expected volatility 53.10% 62.56% Risk-free interest rate 0.09% 1.57% Expected dividend yield —% —% Risk-free Interest Rate : The Company based the risk-free interest rate over the expected term of the award based on the constant maturity rate of U.S. Treasury securities with similar maturities as of the date of grant. Volatility: The Company used an average historical stock price volatility of its own stock and those comparable public companies that were deemed to be representative of future stock price trends. Expected Term: The expected term represents the period for which the Company’s stock-based compensation awards are expected to be outstanding and is based on analyzing the vesting and contractual terms of the awards and the holders’ historical exercise patterns and termination behavior. Expected Dividends: The Company has not paid and does not anticipate paying any dividends in the near future. Stock-Based Compensation Expense The following table summarizes stock-based compensation expense relating to employee and non-employee stock-based awards for the three months ended March 31, 2021 and 2020, included in the condensed consolidated statements of operations as follows (in thousands): Three Months Ended March 31, 2021 2020 Cost of testing services $ 395 $ 247 Cost of product 76 59 Cost of digital and other 108 59 Research and development 1,358 810 Sales and marketing 1,659 971 General and administrative 2,951 2,113 Total $ 6,547 $ 4,259 No tax benefit was recognized related to stock-based compensation expense since the Company has never reported taxable income and has established a full valuation allowance to offset all of the potential tax benefits associated with its deferred tax assets. In addition, no amounts of stock-based compensation expense were capitalized for the periods presented.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES The Company’s effective tax rate may vary from the U.S. federal statutory tax rate due to the change in the mix of earnings in tax jurisdictions with different statutory rates, benefits related to tax credits and the tax impact of non-deductible expenses and other permanent differences between income before income taxes and taxable income. For the three months ended March 31, 2021 and 2020, the Company recorded an income tax benefit of $0.3 million and $0.3 million, respectively. The income tax benefit of $0.3 million is primarily attributable to the recognition of deferred tax assets from foreign losses and acquired deferred tax liabilities that generate a source of income for the recognition of deferred tax assets previously not recognized. The Company assesses the realizability of its net deferred tax assets by evaluating all available evidence, both positive and negative, including (i) cumulative results of operations in recent years, (ii) sources of recent losses, (iii) estimates of future taxable income, and (iv) the length of net operating loss carryforward periods. The Company believes that based on the history of its U.S. losses and other factors, the weight of available evidence indicates that it is more likely than not that it will not be able to realize its U.S. net deferred tax assets. The Company has also placed a valuation allowance on the net deferred tax assets of its Australian operations. Accordingly, the U.S. and Australia net deferred tax assets have been offset by a full valuation allowance. Starting in 2018, companies may be subject to global intangible low tax income (“GILTI”), which is a tax on foreign income in excess of a deemed return on tangible assets of foreign corporations as well as the new base erosion anti-abuse tax (“BEAT”) under the Tax Cuts and Jobs Act of 2017. GILTI will be effectively taxed at a tax rate of 10.5%. Due to the complexity of the GILTI tax rules, companies are allowed to make an accounting policy choice of either (1) treating taxes due on future U.S. inclusions in taxable income related to GILTI as a current-period expense when incurred or (2) factoring such amounts into a company’s measurement of its deferred taxes. The Company has not made an election with respect to GILTI and does not believe that GILTI will have a material impact on the Company’s 2021 taxes. The Company will continue to review the GILTI and BEAT rules to determine their applicability to the Company and the impact that the rules may have on the Company's results of operations and financial condition.

Segment Reporting

Segment Reporting	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Segment Reporting	SEGMENT REPORTING Operating segments are defined as components of an enterprise for which separate financial information is available that is evaluated regularly by the Company’s Chief Operating Decision Maker (“CODM”), or decision making group, whose function is to allocate resources to and assess the performance of the operating segments. The Company has identified its Chief Executive Officer as the CODM. In determining its reportable segments, the Company considered the markets and types of customers served and the products or services provided in those markets. The Company operates in a single reportable segment. Revenues by geographic regions are based upon the customers’ ship-to address for product revenue and the region of testing for testing services revenue. The following table summarizes reportable revenues by geographic regions (in thousands): Three Months Ended March 31, 2021 2020 Testing services revenue United States $ 59,021 $ 31,329 Rest of World 260 113 $ 59,281 $ 31,442 Product revenue United States $ 2,495 $ 2,061 Europe 2,252 2,002 Rest of World 1,031 632 $ 5,778 $ 4,695 Digital and other revenue United States $ 2,288 $ 2,183 Europe 31 30 Rest of World 22 30 $ 2,341 $ 2,243 Total United States $ 63,804 $ 35,573 Total Europe $ 2,283 $ 2,032 Total Rest of World $ 1,313 $ 775 Total $ 67,400 $ 38,380 The following table summarizes long-lived assets, consisting of property and equipment, net, by geographic regions (in thousands): March 31, 2021 December 31, 2020 Long-lived assets: United States $ 10,700 $ 9,888 Europe 302 351 Rest of World 396 465 Total $ 11,398 $ 10,704

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Accounting Policies [Abstract]
Liquidity and Capital Resources	Liquidity and Capital Resources The Company has incurred significant losses and negative cash flows from operations since its inception and had an accumulated deficit of $353.2 million at March 31, 2021. As of March 31, 2021, the Company had cash, cash equivalents and marketable securities of $374.3 million. CMS Accelerated and Advance Payment Program for Medicare Providers On March 27, 2020 the U.S. government enacted the Coronavirus Aid, Relief, and Economic Security Act ( the “ CARES Act”). Pursuant to the CARES Act, the Centers for Medicare & Medicaid Services ( “ CMS”) expanded its Accelerated and Advance Payment Program in order to increase cash flow to providers of services and suppliers impacted by the COVID-19 pandemic. CMS is authorized to provide accelerated or advance payments during the period of the public health emergency to any Medicare provider who submitted a request to the appropriate Medicare Administrative Contractor and met the required qualifications. During April 2020, the Company received an advance payment from CMS of approximately $20.5 million, and recorded the payment as Deferred revenue - CMS advance payment on the Company's condensed consolidated balance sheet. During December 2020, the Company reassessed the Deferred revenue - CMS advance payment and repaid the entire amount in January 2021. The Company recorded the amount as Refund liability - CMS advance payment on the condensed consolidated balance sheet as of December 31, 2020. Refer to Note 8, Balance Sheet Components, for further explanation. CARES Act Provider Relief Fund for Medicare Providers Pursuant to the CARES Act, the U.S. Department of Health & Human Services ( “HHS ”) distributed an initial tranche of $30.0 billion in funds to healthcare providers that received Medicare fee-for-service ( “ FFS”) reimbursements in 2019. These payments to healthcare providers are not loans and will not be required to be repaid. As a condition to receiving these payments, providers must agree to certain terms and conditions and submit sufficient documentation demonstrating that the funds are being used for healthcare-related expenses or lost revenue attributable to the COVID-19 pandemic. Due to the recent enactment of legislation and absence of definitive guidance, there is a high degree of uncertainty around the CARES Act’s implementation and the Company continues to assess the impact on its business. Furthermore, HHS has indicated that it, along with the Office of Inspector General, will be closely monitoring and auditing providers to ensure that recipients comply with the terms and conditions of relief programs and to prevent fraud and abuse. All providers will be subject to civil and criminal penalties for any deliberate omissions, misrepresentations or falsifications of any information given to HHS. Providers will be distributed a portion of the initial $30.0 billion of funds based on their share of total Medicare FFS reimbursements made by the U.S. in 2019. During April 2020, the Company received a payment of approximately $4.8 million representing its portion of the initial tranche of funds, recorded in other income (expense), net on the condensed consolidated statements of operations. The Company is complying with the key terms and provisions of the CARES Act Provider Relief Fund, which includes, among other things, the requirement that the Company maintain appropriate records and cost documentation. The Company has registered with HHS to submit financial data indicating the use of the funds the Company received pursuant to the CARES Act Provider Relief Fund. The Company will be notified by HHS when the Provider Relief Fund Reporting Portal is open for reporting on the use of Provider Relief Fund payments.
Basis of Presentation	Basis of Presentation The accompanying unaudited condensed consolidated financial statements have been prepared in conformity with accounting principles generally accepted in the United States of America (“U.S. GAAP”), and follow the requirements of the Securities and Exchange Commission (the “SEC”) for interim reporting. As permitted under those rules, certain notes and other financial information that are normally required by U.S. GAAP can be condensed or omitted. These unaudited condensed consolidated financial statements have been prepared on the same basis as the Company’s annual consolidated financial statements and, in the opinion of management, reflect all adjustments, consisting only of normal recurring adjustments that are necessary for a fair statement of the Company’s financial information. The condensed consolidated balance sheet as of December 31, 2020 has been derived from audited consolidated financial statements as of that date but does not include all of the financial information required by U.S. GAAP for complete financial statements. Operating results for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021.
Changes in Presentation	Correction to Presentation The presentation of certain prior period amounts within the accompanying condensed consolidated statements of operations have been corrected, including creating separate line items for the presentation of cost of testing services, cost of product and cost of digital and other, which were previously reported, in aggregate, in total cost of revenue of $12.4 million for the three months ended March 31, 2020. These corrections had no effect on loss from operations, loss before taxes, or net loss. The Company evaluated these corrections, considering both qualitative and quantitative factors, and concluded they are immaterial to previously issued financial statements.
Use of Estimates	Use of Estimates The preparation of unaudited condensed consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities and the reported amounts of revenues and expenses in the unaudited condensed consolidated financial statements and accompanying notes. On an ongoing basis, management evaluates its estimates, including those related to transaction price estimates used for testing services revenue; standalone fair value of digital revenue performance obligations; accrued expenses for clinical studies; inventory valuation; the fair value of issued common stock warrants and embedded derivatives; the fair value of assets and liabilities acquired in a business combination or an assets acquisition (including identifiable intangible assets acquired); the fair value of contingent consideration recorded in connection with a business combination; the grant date fair value assumptions used to estimate stock-based compensation expense; income taxes; impairment of long-lived assets and indefinite-lived assets (including goodwill); and legal contingencies. Actual results could differ from those estimates.
Concentrations of Credit Risk and Other Risks and Uncertainties	Concentrations of Credit Risk and Other Risks and Uncertainties For the three months ended March 31, 2021 and 2020 , approximately 60% and 53%, respectively, of total revenue was derived from Medicare. As of March 31, 2021 and December 31, 2020, approximately 31% and 28%, respectively, of accounts receivable was due from Medicare. No other payer or customer represented more than 10% of accounts receivable on either March 31, 2021 or December 31, 2020.
Marketable Securities	Marketable Securities The Company considers all highly liquid investments in securities with a maturity of greater than three months at the time of purchase to be marketable securities. As of March 31, 2021, the Company’s marketable securities consisted of corporate debt securities with maturities of greater th an three months but less than twelve months at the time of purchase. Thes e marketable securities are classified as current assets on the condensed consolidated balance sheet. The Company classifies its marketable securities as held-to-maturity at the time of purchase and reevaluates such designation at each balance sheet date. The Company has the positive intent and ability to hold these marketable securities to maturity. Marketable securities are carried at amortized cost and are adjusted for amortization of premiums and accretion of discounts to maturity, which is included in interest income (expense), net on the condensed consolidated statements of operations. Realized gains and losses and declines in value judged to be other-than-temporary, if any, on marketable securities are included in interest income (expense), net. The cost of securities sold will be determined using specific identification.
Leases	Leases Effective January 1, 2019, the Company adopted Accounting Standard Codification (“ASC”) Topic 842, Leases using the optional transition method and applied the standard only to leases that existed at that date. The Company determines if an arrangement is or contains a lease at contract inception. A right-of-use (“ROU”) asset, representing the underlying asset during the lease term, and a lease liability, representing the payment obligation arising from the lease, are recognized on the condensed consolidated balance sheet at lease commencement based on the present value of the payment obligation. For operating leases, expense is recognized on a straight-line basis over the lease term. For finance leases, interest expense on the lease liability is recognized using the effective interest method and amortization of the ROU asset is recognized on a straight-line basis over the shorter of the estimated useful life of the asset or the lease term. Short-term leases with an initial term of 12 months or less are not recorded on the balance sheet. The present value of lease payments is determined by using the interest rate implicit in the lease, if that rate is readily determinable; otherwise, the Company uses its incremental borrowing rate. The incremental borrowing rate is determined by using the rate of interest that the Company would pay to borrow on a collateralized basis an amount equal to the lease payments for a similar term and in a similar economic environment. As of March 31, 2021, the Company’s leases had remaining terms of 0.21 years to 7.92 years, some of which include options to extend the lease term.
Recent Accounting Pronouncements	Recent Accounting Pronouncements In October 2020, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2020-10, Codification Improvements, which contains amendments that improve the consistency of the ASC by including all disclosure guidance in the appropriate Disclosure Section (Section 50). The FASB provided transition guidance for all the amendments in this ASU. The amendments in Sections B and C (Section A has been removed) of this ASU are effective for annual periods beginning after December 15, 2020 for public business entities. Early application of the amendments in this ASU is permitted for public business entities for any annual or interim period for which financial statements have not been issued. The amendments in this ASU should be applied retrospectively. The Company adopted the standard on January 1, 2021. The adoption of the new standard did not have an impact on the Company's condensed consolidated financial statements and disclosures.

Net Loss Per Share (Tables)

Net Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Computation of Basic and Diluted Net Loss Per Share	The following tables set forth the computation of the Company’s basic and diluted net loss per share (in thousands, except shares and per share data): Three Months Ended March 31, 2021 2020 Numerator: Net loss used to compute basic and diluted net loss per share $ (687) $ (5,823) Denominator: Weighted-average shares used to compute basic and diluted net loss per share 51,181,160 42,823,427 Net loss per share: Basic and diluted $ (0.01) $ (0.14)
Potentially Dilutive Securities Excluded from Diluted Net Loss Per Share	The following potentially dilutive securities have been excluded from diluted net loss per share as of March 31, 2021 and 2020 because their effect would be antidilutive: Three Months Ended March 31, 2021 2020 Shares of common stock subject to outstanding options 2,592,281 2,845,862 Shares of common stock subject to outstanding common stock warrants 6,264 49,006 Restricted stock units 1,853,419 1,502,012 Total common stock equivalents 4,451,964 4,396,880

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value of Financial Assets and Liabilities Measured on Recurring Basis	The following table sets forth the Company’s financial assets and liabilities, measured at fair value on a recurring basis, as of March 31, 2021 and December 31, 2020 (in thousands): March 31, 2021 Fair Value Measured Using (Level 1) (Level 2) (Level 3) Total Balance Assets Money market funds $ 280,099 $ — $ — $ 280,099 Liabilities Common stock warrant liability $ — $ — $ 420 $ 420 December 31, 2020 Fair Value Measured Using (Level 1) (Level 2) (Level 3) Total Balance Assets Money market funds $ 85,797 $ — $ — $ 85,797 Liabilities Common stock warrant liability $ — $ — $ 447 $ 447
Summary of Issuances, Exercises, Changes in Fair Value and Reclassifications of Level 3 Financial Instruments	The following table presents the issuances, exercises, changes in fair value and reclassifications of the Company’s Level 3 financial instruments that are measured at fair value on a recurring basis (in thousands): (Level 3) Common Stock Warrant Liability Balance as of December 31, 2020 $ 447 Exercise of warrants — Change in estimated fair value (27) Balance as of March 31, 2021 $ 420
Summary of Common Stock Warrant Liability Valuation Assumptions	Common Stock Warrant Liability Valuation Assumptions: March 31, 2021 December 31, 2020 Private Placement Common Stock Warrant Liability Stock Price $ 68.09 $ 72.45 Exercise Price $ 1.12 $ 1.12 Remaining term (in years) 2.04 2.28 Volatility 72.00 % 73.00 % Risk-free interest rate 0.17 % 0.14 %

Cash and Marketable Securities

Cash and Marketable Securities (Tables)	3 Months Ended
	Mar. 31, 2021
Cash and Cash Equivalents [Abstract]
Schedule of Cash and Cash Equivalents	A reconciliation of cash, cash equivalents, and restricted cash reported within the condensed consolidated balance sheets to the amount reported within the condensed consolidated statements of cash flows is shown in the table below (in thousands): March 31, 2021 December 31, 2020 March 31, 2020 December 31, 2019 Cash and cash equivalents $ 309,324 $ 134,669 $ 32,191 $ 38,223 Restricted cash 269 270 242 256 Total cash, cash equivalents, and restricted cash at the end of the period $ 309,593 $ 134,939 $ 32,433 $ 38,479
Debt Securities, Held-to-maturity	The amortized cost, gross unrealized holding losses, and fair value of the Company’s marketable securities by major security type at each balance sheet date are summarized in the table below (in thousands): March 31, 2021 Amortized Cost Unrealized Holding Losses Fair Value Short-term marketable securities: Corporate debt securities $ 64,963 $ (66) $ 64,897 Total short-term marketable securities $ 64,963 $ (66) $ 64,897 December 31, 2020 Amortized Cost Unrealized Holding Losses Fair Value Short-term marketable securities: Corporate debt securities $ 90,034 $ (136) $ 89,898 Total short-term marketable securities $ 90,034 $ (136) $ 89,898

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Summary of Intangible Assets	The following tables present details of the Company’s intangible assets as of March 31, 2021 ($ in thousands): March 31, 2021 Gross Carrying Amount Accumulated Amortization Foreign Currency Translation Net Carrying Amount Weighted Average Remaining Useful Life Intangible assets with finite lives: Acquired and developed technology $ 33,569 $ (9,692) $ (1,262) $ 22,615 9.0 Customer relationships 19,308 (5,015) (953) 13,340 10.6 Commercialization rights 8,079 (1,241) — 6,838 8.4 Trademarks and tradenames 2,380 (856) (110) 1,414 9.6 Total intangible assets with finite lives $ 63,336 $ (16,804) $ (2,325) $ 44,207 Acquired in-process technology 1,250 — — 1,250 Total intangible assets $ 64,586 $ (16,804) $ (2,325) $ 45,457 The following table presents details of the Company’s intangible assets as of December 31, 2020 ($ in thousands): December 31, 2020 Gross Carrying Amount Accumulated Amortization Foreign Currency Translation Net Carrying Amount Weighted Average Remaining Useful Life Intangible assets with finite lives: Acquired and developed technology $ 31,209 $ (8,991) $ (725) $ 21,493 9.1 Customer relationships 18,168 (4,684) (449) 13,035 10.9 Commercialization rights 8,079 (1,039) — 7,040 8.7 Trademarks and tradenames 2,360 (804) (19) 1,537 9.9 Total intangible assets with finite lives $ 59,816 $ (15,518) $ (1,193) $ 43,105 Acquired in-process technology 1,250 — — 1,250 Total intangible assets $ 61,066 $ (15,518) $ (1,193) $ 44,355
Summary of Estimated Future Amortization Expense of Intangible Assets	The following table summarizes the Company’s estimated future amortization expense of intangible assets with finite lives as of March 31, 2021 (in thousands): Years Ending December 31, Cost of Testing Services Cost of Product Cost of Digital and Other Sales and Marketing Total Remainder of 2021 $ 987 $ 1,430 $ 323 $ 1,083 $ 3,823 2022 1,316 1,906 431 1,437 5,090 2023 1,316 1,906 431 1,427 5,080 2024 1,316 1,906 431 1,427 5,080 2025 1,316 1,906 431 1,427 5,080 Thereafter 5,457 5,020 1,622 7,955 20,054 Total future amortization expense $ 11,708 $ 14,074 $ 3,669 $ 14,756 $ 44,207

Balance Sheet Components (Table

Balance Sheet Components (Tables)	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Inventory	Inventory consisted of the following (in thousands): March 31, 2021 December 31, 2020 Finished goods $ 2,416 $ 1,702 Work in progress 3,210 2,936 Raw materials 8,095 5,374 Total inventory $ 13,721 $ 10,012
Components of Accrued and Other Liabilities	Accrued and other liabilities consisted of the following (in thousands): March 31, 2021 December 31, 2020 Deferred revenue $ 3,522 $ 3,530 Clinical studies 7,023 6,733 Deferred payments for intangible assets 2,000 2,000 Short-term lease liability 3,126 2,033 Test sample processing fees 505 416 Accrued royalty 1,342 1,072 Contingent consideration 694 738 Professional fees 2,393 1,529 Other accrued expenses 3,033 2,551 Total accrued and other liabilities $ 23,638 $ 20,602

Commitments and Contingencies (

Commitments and Contingencies (Tables)	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Summary of Lease Cost	The following table summarizes the lease cost for the three months ended March 31, 2021 and 2020 (in thousands): Three Months Ended March 31, 2021 2020 Operating lease cost $ 1,205 $ 1,119 Finance lease cost 30 53 Total lease cost $ 1,235 $ 1,172 Finance lease cost includes interest from the lease liability and amortization of the ROU asset. Other information: Weighted-average remaining lease term - Operating leases (in years) 6.78 Weighted-average remaining lease term - Finance leases (in years) 0.22 Weighted-average discount rate - Operating leases (%) 10.5% Weighted-average discount rate - Finance leases (%) 4.8%
Future Minimum Lease Commitments under Operating and Finance Leases	Maturities of operating and finance lease liabilities as of March 31, 2021 are as follows (in thousands): Year Ending December 31, Finance Leases Operating Leases Remainder of 2021 $ 34 $ 3,718 2022 — 4,971 2023 — 3,724 2024 — 3,846 2025 — 3,988 Thereafter — 10,256 Total lease payments 34 30,503 Less imputed interest — 8,915 Present value of future minimum lease payments $ 34 21,588 Less operating lease liability, current portion 3,126 Operating lease liability, long-term portion $ 18,462

Warrants (Tables)

Warrants (Tables)	3 Months Ended
	Mar. 31, 2021
Warrants and Rights Note Disclosure [Abstract]
Components of Warrants Outstanding	As of March 31, 2021, outstanding warrants to purchase common stock were: Classified as Original Term Exercise Price Number of Shares Underlying Warrants Original issue date: April 2016 Liability 7 years $ 1.12 6,264 6,264

Stock Incentive Plans (Tables)

Stock Incentive Plans (Tables)	3 Months Ended
	Mar. 31, 2021
Share-based Payment Arrangement [Abstract]
Summary of Option, Unvested RSU Activity under 2014 Equity Incentive Plan and 2016 Inducement Equity Incentive Plan and Related Information	The following table summarizes option and RSU activity under the Company’s 2014 Equity Incentive Plan, 2016 Inducement Equity Incentive Plan, and 2019 Inducement Equity Incentive Plan, and related information: Shares Stock Weighted- Number of Weighted- Balance—December 31, 2020 672,968 2,670,398 $ 21.92 1,884,866 $ 28.42 Additional shares authorized 1,977,647 — — — — Common stock awards for services (1,339) — — — — RSUs granted (246,379) — — 246,379 82.62 RSUs vested — — — (207,881) 24.06 Options granted (127,925) 127,925 81.06 — — Options exercised — (139,579) 13.99 — — Repurchase of common stock under employee incentive plans 74,434 — — — — RSUs forfeited 69,945 — — (69,945) 29.32 Options forfeited 66,213 (66,213) 25.70 — — Options expired 250 (250) 22.59 — — Balance—March 31, 2021 2,485,814 2,592,281 $ 25.17 1,853,419 $ 36.14
Summary of Options Outstanding and Exercisable Vested or Expected to Vest	Options outstanding that have vested and are expected to vest at March 31, 2021 are as follows: Number of Shares Issued Weighted-Average Weighted-Average Remaining Contractual Life (Years) Aggregate Intrinsic Value Vested 1,045 $ 16.09 6.54 $ 54,318 Expected to vest 1,398 31.91 8.68 52,508 Total 2,443 $ 106,826
Weighted-Average Assumptions Used to Estimate Fair Values of Share-Based Awards	The estimated fair values of employee stock options and ESPP shares were estimated using the Black-Scholes option pricing model based on the following weighted average assumptions: Three Months Ended March 31, 2021 2020 Employee stock options Expected term (in years) 6.0 6.0 Expected volatility 77.69% 74.00% Risk-free interest rate 0.68% 1.35% Expected dividend yield —% —% Employee stock purchase plan Expected term (in years) 0.5 0.5 Expected volatility 53.10% 62.56% Risk-free interest rate 0.09% 1.57% Expected dividend yield —% —%
Summary of Expense Relating to Employee and Nonemployee Stock-Based Payment Awards from Stock Options and RSUs	The following table summarizes stock-based compensation expense relating to employee and non-employee stock-based awards for the three months ended March 31, 2021 and 2020, included in the condensed consolidated statements of operations as follows (in thousands): Three Months Ended March 31, 2021 2020 Cost of testing services $ 395 $ 247 Cost of product 76 59 Cost of digital and other 108 59 Research and development 1,358 810 Sales and marketing 1,659 971 General and administrative 2,951 2,113 Total $ 6,547 $ 4,259

Segment Reporting (Tables)

Segment Reporting (Tables)	3 Months Ended
	Mar. 31, 2021
Segment Reporting [Abstract]
Reportable Revenues by Geographic Regions	Revenues by geographic regions are based upon the customers’ ship-to address for product revenue and the region of testing for testing services revenue. The following table summarizes reportable revenues by geographic regions (in thousands): Three Months Ended March 31, 2021 2020 Testing services revenue United States $ 59,021 $ 31,329 Rest of World 260 113 $ 59,281 $ 31,442 Product revenue United States $ 2,495 $ 2,061 Europe 2,252 2,002 Rest of World 1,031 632 $ 5,778 $ 4,695 Digital and other revenue United States $ 2,288 $ 2,183 Europe 31 30 Rest of World 22 30 $ 2,341 $ 2,243 Total United States $ 63,804 $ 35,573 Total Europe $ 2,283 $ 2,032 Total Rest of World $ 1,313 $ 775 Total $ 67,400 $ 38,380
Long-Lived Assets Consisting of Property and Equipment, Net by Geographic Regions	The following table summarizes long-lived assets, consisting of property and equipment, net, by geographic regions (in thousands): March 31, 2021 December 31, 2020 Long-lived assets: United States $ 10,700 $ 9,888 Europe 302 351 Rest of World 396 465 Total $ 11,398 $ 10,704

Organization and Description _2

Organization and Description of Business - Additional Information (Detail)	Feb. 11, 2021USD ($)shares	Jan. 25, 2021USD ($)$ / sharesshares	Jun. 15, 2020USD ($)$ / sharesshares	Apr. 30, 2020USD ($)	Mar. 31, 2021USD ($)uniqueSolutioncenterphlebotomistpatient	Dec. 31, 2020USD ($)	Jan. 31, 2018patient
Schedule of Capitalization, Equity [Line Items]
Number of renal transplant patients (more than) | patient							1,700
Number of transplant centers offering RemoTraC (more than) | center					200
Number of patients enrolled in RemoTraC (more than) | patient					7,000
Number of mobile phlebotomists (more than) | phlebotomist					10,000
Accumulated deficit					$ 353,214,000	$ 352,527,000
Cash, cash equivalents, and short-term investments					374,300,000
Accelerated and advanced payment				$ 20,500,000
Grants receivable					$ 30,000,000,000
Medicare fee-for-service reimbursements proceeds, initial tranche				$ 4,800,000
Public Offering
Schedule of Capitalization, Equity [Line Items]
Shares issued and sold (in shares) | shares		1,923,077	4,492,187
Sale of stock (in usd per share) | $ / shares		$ 91	$ 32
Sale of stock, consideration received on transaction		$ 164,000,000	$ 134,600,000
Over-Allotment Option
Schedule of Capitalization, Equity [Line Items]
Shares issued and sold (in shares) | shares	288,461
Sale of stock, consideration received on transaction	$ 24,700,000
XynManagement, Inc.
Schedule of Capitalization, Equity [Line Items]
Number of unique solutions | uniqueSolution					2
Medicare | AlloSure Kidney
Schedule of Capitalization, Equity [Line Items]
Reimbursement rate					$ 2,841
Medicare | AlloMap Heart
Schedule of Capitalization, Equity [Line Items]
Reimbursement rate					3,240
Medicare | AlloSure Heart
Schedule of Capitalization, Equity [Line Items]
Reimbursement rate					$ 2,753

Summary of Significant Accoun_3

Summary of Significant Accounting Policies - Concentration of Credit Risk (Detail) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Jun. 30, 2020
Medicare | Revenues | Customer Concentration Risk
Concentration Risk [Line Items]
Concentration risk percentage	60.00%	53.00%
Medicare | Accounts Receivable | Credit Concentration Risk
Concentration Risk [Line Items]
Concentration risk percentage	31.00%		28.00%
Previously Reported
Concentration Risk [Line Items]
Cost of goods and services		$ 12.4

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Leases (Detail)	3 Months Ended
	Mar. 31, 2021
Minimum
Summary Of Significant Accounting Policies [Line Items]
Remaining lease terms	2 months 15 days
Maximum
Summary Of Significant Accounting Policies [Line Items]
Remaining lease terms	7 years 11 months 1 day

Net Loss Per Share - Computatio

Net Loss Per Share - Computation of Basic and Diluted Net Loss Per Share (Detail) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net loss used to compute basic and diluted net loss per share	$ (687)	$ (5,823)
Denominator:
Weighted-average shares used to compute basic and diluted net loss per share (in shares)	51,181,160	42,823,427
Net loss per share:
Basic and diluted (in dollars per share)	$ (0.01)	$ (0.14)

Net Loss Per Share - Potentiall

Net Loss Per Share - Potentially Dilutive Securities Excluded from Diluted Net Loss Per Share (Detail) - shares	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share attributable to common stockholders (in shares)	4,451,964	4,396,880
Shares of common stock subject to outstanding options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share attributable to common stockholders (in shares)	2,592,281	2,845,862
Shares of common stock subject to outstanding common stock warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share attributable to common stockholders (in shares)	6,264	49,006
Restricted stock units
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential dilutive securities excluded from diluted net loss per share attributable to common stockholders (in shares)	1,853,419	1,502,012

Fair Value Measurements - Fair

Fair Value Measurements - Fair Value of Financial Assets and Liabilities Measured on Recurring Basis (Detail) - Recurring - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Assets
Money market funds	$ 280,099	$ 85,797
Liabilities
Common stock warrant liability	420	447
Fair Value Measured Using - (Level 1)
Assets
Money market funds	280,099	85,797
Liabilities
Common stock warrant liability	0	0
Fair Value Measured Using - (Level 2)
Assets
Money market funds	0	0
Liabilities
Common stock warrant liability	0	0
Fair Value Measured Using - (Level 3)
Assets
Money market funds	0	0
Liabilities
Common stock warrant liability	$ 420	$ 447

Fair Value Measurements - Summa

Fair Value Measurements - Summary of Issuances, Exercises, Changes in Fair Value and Reclassifications of Level 3 Financial Instruments (Detail) - Common Stock Warrants Liability - (Level 3) - Common Stock Warrant Liability $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance	$ 447
Exercise of warrants	0
Change in estimated fair value	(27)
Ending balance	$ 420

Fair Value Measurements - Sum_2

Fair Value Measurements - Summary of Common Stock Warrant Liability Valuation Assumptions (Detail) - Private Placement Common Stock Warrant Liability	3 Months Ended	12 Months Ended
	Mar. 31, 2021$ / shares	Dec. 31, 2020$ / shares
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Stock price (in dollars per share)	$ 68.09	$ 72.45
Exercise Price
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Exercise price (in dollars per share)	$ 1.12	$ 1.12
Remaining Term (in years)
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Remaining term (in years)	2 years 14 days	2 years 3 months 10 days
Volatility
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability measurement input	0.7200	0.7300
Risk Free Interest Rate
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Derivative liability measurement input	0.0017	0.0014

Cash and Marketable Securitie_2

Cash and Marketable Securities - Reconciliation of Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Mar. 31, 2020	Dec. 31, 2019
Cash and Cash Equivalents [Abstract]
Cash and cash equivalents	$ 309,324	$ 134,669	$ 32,191	$ 38,223
Restricted cash	269	270	242	256
Total cash, cash equivalents, and restricted cash at the end of the period	$ 309,593	$ 134,939	$ 32,433	$ 38,479

Cash and Marketable Securitie_3

Cash and Marketable Securities - Components of Marketable Securities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	$ 64,963	$ 90,034
Unrealized Holding Losses	(66)	(136)
Fair Value	64,897	89,898
Corporate Debt Securities
Schedule of Held-to-maturity Securities [Line Items]
Amortized Cost	64,963	90,034
Unrealized Holding Losses	(66)	(136)
Fair Value	$ 64,897	$ 89,898

Business Combinations - Additio

Business Combinations - Additional Information (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Jan. 31, 2021	Dec. 31, 2020
Business Acquisition [Line Items]
Goodwill	$ 26,109		$ 23,857
TransChart LLC
Business Acquisition [Line Items]
Goodwill		$ 2,300
Intangible assets		$ 2,000

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Summary of Intangible Assets (Detail) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Intangible assets with finite lives:
Gross Carrying Amount	$ 63,336	$ 59,816
Accumulated Amortization	(16,804)	(15,518)
Foreign Currency Translation	(2,325)	(1,193)
Total	44,207	43,105
Intangible Assets, Net (Excluding Goodwill)
Total intangible assets - gross carrying amount	64,586	61,066
Total intangible assets, net	45,457	44,355
Acquired and developed technology
Intangible assets with finite lives:
Gross Carrying Amount	33,569	31,209
Accumulated Amortization	(9,692)	(8,991)
Foreign Currency Translation	(1,262)	(725)
Total	$ 22,615	$ 21,493
Weighted Average Remaining Useful Life (In Years)	9 years	9 years 1 month 6 days
Customer relationships
Intangible assets with finite lives:
Gross Carrying Amount	$ 19,308	$ 18,168
Accumulated Amortization	(5,015)	(4,684)
Foreign Currency Translation	(953)	(449)
Total	$ 13,340	$ 13,035
Weighted Average Remaining Useful Life (In Years)	10 years 7 months 6 days	10 years 10 months 24 days
Commercialization rights
Intangible assets with finite lives:
Gross Carrying Amount	$ 8,079	$ 8,079
Accumulated Amortization	(1,241)	(1,039)
Foreign Currency Translation	0	0
Total	$ 6,838	$ 7,040
Weighted Average Remaining Useful Life (In Years)	8 years 4 months 24 days	8 years 8 months 12 days
Trademarks and tradenames
Intangible assets with finite lives:
Gross Carrying Amount	$ 2,380	$ 2,360
Accumulated Amortization	(856)	(804)
Foreign Currency Translation	(110)	(19)
Total	$ 1,414	$ 1,537
Weighted Average Remaining Useful Life (In Years)	9 years 7 months 6 days	9 years 10 months 24 days
Acquired in-process technology
Intangible assets with indefinite lives
Net carrying amount	$ 1,250	$ 1,250

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Goodwill And Intangible Assets [Line Items]
Goodwill	$ 26,109		$ 23,857
Amortization expense of intangible assets	1,300	$ 1,100
Cost of Testing Services
Goodwill And Intangible Assets [Line Items]
Amortization expense of intangible assets	300	300
Cost of Product
Goodwill And Intangible Assets [Line Items]
Amortization expense of intangible assets	500	400
Cost of Digital and Other
Goodwill And Intangible Assets [Line Items]
Amortization expense of intangible assets	100	100
Sales and Marketing Expense
Goodwill And Intangible Assets [Line Items]
Amortization expense of intangible assets	$ 400	$ 300

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Summary of Estimated Future Amortization Expense of Intangible Assets with Finite Lives (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of 2021	$ 3,823
2022	5,090
2023	5,080
2024	5,080
2025	5,080
Thereafter	20,054
Total	44,207	$ 43,105
Cost of Testing Services
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of 2021	987
2022	1,316
2023	1,316
2024	1,316
2025	1,316
Thereafter	5,457
Total	11,708
Cost of Product
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of 2021	1,430
2022	1,906
2023	1,906
2024	1,906
2025	1,906
Thereafter	5,020
Total	14,074
Cost of Digital and Other
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of 2021	323
2022	431
2023	431
2024	431
2025	431
Thereafter	1,622
Total	3,669
Sales and Marketing
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
Remainder of 2021	1,083
2022	1,437
2023	1,427
2024	1,427
2025	1,427
Thereafter	7,955
Total	$ 14,756

Balance Sheet Components - Summ

Balance Sheet Components - Summary of Inventory (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Finished goods	$ 2,416	$ 1,702
Work in progress	3,210	2,936
Raw materials	8,095	5,374
Total inventory	$ 13,721	$ 10,012

Balance Sheet Components - Comp

Balance Sheet Components - Components of Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Deferred revenue	$ 3,522	$ 3,530
Clinical studies	7,023	6,733
Deferred payments for intangible assets	2,000	2,000
Short-term lease liability	3,126	2,033
Test sample processing fees	505	416
Accrued royalty	1,342	1,072
Contingent consideration	694	738
Professional fees	2,393	1,529
Other accrued expenses	3,033	2,551
Total accrued and other liabilities	$ 23,638	$ 20,602

Balance Sheet Components - Addi

Balance Sheet Components - Additional Information (Details) $ in Millions	1 Months Ended
	Apr. 30, 2020USD ($)
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accelerated and advanced payment	$ 20.5

Commitments and Contingencies -

Commitments and Contingencies - Summary of Lease Cost (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Operating lease cost	$ 1,205	$ 1,119
Finance lease cost	30	53
Total lease cost	$ 1,235	$ 1,172

Commitments and Contingencies_2

Commitments and Contingencies - Summary of Other Information Related to Lease (Detail)	Mar. 31, 2021
Other information:
Weighted-average remaining lease term - Operating leases (in years)	6 years 9 months 10 days
Weighted-average remaining lease term - Finance leases (in years)	2 months 19 days
Weighted-average discount rate - Operating leases	10.50%
Weighted-average discount rate - Finance leases	4.80%

Commitments and Contingencies_3

Commitments and Contingencies - Additional Information (Detail) $ in Thousands	1 Months Ended
	Jun. 30, 2014milestone_payment	Mar. 31, 2021USD ($)	Jan. 01, 2021	Dec. 31, 2020USD ($)	Jan. 01, 2020USD ($)
Commitments and Contingencies Disclosure [Abstract]
Lease extension term period			8 years 2 months
Operating lease, right-of-use asset increase amount					$ 13,000
Operating leases right-of-use assets		$ 18,289		$ 15,228
Less operating lease liability, current portion		3,126		2,033
Operating lease liability, less current portion		$ 18,462		$ 16,069
Number of milestone payments | milestone_payment	6

Commitments and Contingencies_4

Commitments and Contingencies - Future Minimum Lease Commitments under Operating and Finance Leases (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Finance Leases
Remainder of 2021	$ 34
2022	0
2023	0
2024	0
2025	0
Thereafter	0
Total lease payments	34
Less imputed interest	0
Present value of future minimum lease payments	34
Operating Leases
Remainder of 2021	3,718
2022	4,971
2023	3,724
2024	3,846
2025	3,988
Thereafter	10,256
Total lease payments	30,503
Less imputed interest	8,915
Present value of future minimum lease payments	21,588
Less operating lease liability, current portion	3,126	$ 2,033
Operating lease liability, less current portion	$ 18,462	$ 16,069

401(K) Plan - Additional Inform

401(K) Plan - Additional Information (Detail) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Retirement Benefits [Abstract]
Expense incurred related to plan	$ 0.5	$ 0.3

Warrants - Additional Informati

Warrants - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Warrants and Rights Note Disclosure [Abstract]
Purchase of common stock warrants exercised (in shares)	0	272,000
Proceeds from warrant exercises (less than)	$ 0	$ 304
Number of warrants exercised on cashless basis (in shares)		34,000
Shares issued (in shares)		24,000

Warrants - Outstanding Warrants

Warrants - Outstanding Warrants To Purchase Common Stock Warrants (Detail) - Common Stock	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Class of Warrant or Right [Line Items]
Number of shares underlying warrants (in shares)	6,264
Original issue date of April 2016
Class of Warrant or Right [Line Items]
Exercise price (in dollars per share) | $ / shares	$ 1.12
Number of shares underlying warrants (in shares)	6,264
Original issue date of April 2016 | Remaining Term (in years)
Class of Warrant or Right [Line Items]
Original Term	7 years

Stock Incentive Plans - Summary

Stock Incentive Plans - Summary of Option, Unvested RSU Activity under 2014 Equity Incentive Plan and 2016 Inducement Equity Incentive Plan and Related Information (Detail)	3 Months Ended
	Mar. 31, 2021$ / sharesshares
Shares Available for Grant
Shares available for grant beginning balance (in shares)	672,968
Additional options authorized (in shares)	1,977,647
Common stock awards for services (in shares)	(1,339)
RSUs granted (in shares)	(246,379)
Options granted (in shares)	(127,925)
Repurchase of common stock under employee incentive plans (in shares)	74,434
RSUs forfeited (in shares)	69,945
Options forfeited (in shares)	66,213
Options expired (in shares)	250
Shares available for grant ending balance (in shares)	2,485,814
Stock Options Outstanding
Stock options outstanding beginning balance (in shares)	2,670,398
Options granted (in shares)	127,925
Stock option exercised (in shares)	(139,579)
Options forfeited (in shares)	(66,213)
Options expired (in shares)	(250)
Stock options outstanding ending balance (in shares)	2,592,281
Weighted Average Exercise Price
Weighted average exercise price beginning balance (in dollars per share) | $ / shares	$ 21.92
Weighted average exercise price - options granted (in dollars per share) | $ / shares	81.06
Weighted average exercise price - options exercised (in dollars per share) | $ / shares	13.99
Weighted average exercise price - options forfeited (in dollars per share) | $ / shares	25.70
Weighted average exercise price - options expired (in dollars per share) | $ / shares	22.59
Weighted average exercise price ending balance (in dollars per share) | $ / shares	$ 25.17
Number of RSU Shares
RSUs granted (in shares)	246,379
RSUs forfeited (in shares)	(69,945)
Restricted Stock Units
Shares Available for Grant
RSUs granted (in shares)	(246,379)
RSUs forfeited (in shares)	69,945
Number of RSU Shares
Number of RSU shares beginning balance (in shares)	1,884,866
RSUs granted (in shares)	246,379
RSUs vested (in shares)	(207,881)
RSUs forfeited (in shares)	(69,945)
Number of RSU shares ending balance (in shares)	1,853,419
Weighted Average Grant Date Fair Value
Weighted average grant date fair value beginning balance (in dollars per share) | $ / shares	$ 28.42
Weighted average grant date fair value - RSUs granted (in dollars per share) | $ / shares	82.62
Weighted average grant date fair value - RSUs vested (in dollars per share) | $ / shares	24.06
Weighted average grant date fair value - RSUs forfeited (in dollars per share) | $ / shares	29.32
Weighted average grant date fair value ending balance (in dollars per share) | $ / shares	$ 36.14

Stock Incentive Plans - Additio

Stock Incentive Plans - Additional Information (Detail) - USD ($)	Jan. 02, 2020	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total intrinsic value of options exercised		$ 9,100,000	$ 700,000
Share-based compensation expense tax benefit recognized		0
Share-based compensation expense capitalized		$ 0
2014 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum portion of employee ESPP plan contribution		15.00%
Maximum value of employee purchased shares per calendar year		$ 25,000
Offering period for employee stock purchases		6 months
Applicable exercise date an offering period shall be equal to percentage of the lower of fair market value of common stock		85.00%
Issuance of common stock under ESPP (in shares)	24,052
Aggregate proceeds from the issuance of shares	$ 800,000
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Intrinsic value of RSUs		$ 126,200,000
Total unrecognized compensation costs related to stock options and RSUs		$ 50,700,000
Stock options and RSUs expected weighted average period		1 year 10 months 28 days
Employee Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options and RSUs expected weighted average period		2 years 10 months 20 days
Total fair value of options vested during period		$ 2,700,000
Total unrecognized compensation costs related to stock options		$ 25,200,000

Stock Incentive Plans - Summa_2

Stock Incentive Plans - Summary of Options Outstanding Vested and Expected to Vest (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)$ / sharesshares
Share-based Payment Arrangement [Abstract]
Number of vested shares (in shares) | shares	1,045
Number of shares expected to vest (in shares) | shares	1,398
Number of shares total (in shares) | shares	2,443
Weighted-average exercise price vested (in dollars per share) | $ / shares	$ 16.09
Weighted-average exercise price expected to vest (in dollars per share) | $ / shares	$ 31.91
Weighted-average remaining contractual life vested (in years)	6 years 6 months 14 days
Weighted-average remaining contractual life expected to vest (in years)	8 years 8 months 4 days
Aggregate intrinsic value vested | $	$ 54,318
Aggregate intrinsic value expected to vest | $	52,508
Aggregate intrinsic value total | $	$ 106,826

Stock Incentive Plans - Weighte

Stock Incentive Plans - Weighted-Average Assumptions Used to Estimated Fair Values of Share-Based Awards (Detail)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 months	6 months
Expected volatility	53.10%	62.56%
Risk-free interest rate	0.09%	1.57%
Expected dividend yield	0.00%	0.00%
Shares of common stock subject to outstanding options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Expected term (in years)	6 years	6 years
Expected volatility	77.69%	74.00%
Risk-free interest rate	0.68%	1.35%
Expected dividend yield	0.00%	0.00%

Stock Incentive Plans - Summa_3

Stock Incentive Plans - Summary of Expense Relating to Employee and Nonemployee Stock-Based Payment Awards from Stock Options and RSUs (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	$ 6,547	$ 4,259
Cost of testing services
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	395	247
Cost of product
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	76	59
Cost of digital and other
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	108	59
Research and development
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	1,358	810
Sales and Marketing
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	1,659	971
General and administrative
Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items]
Share based compensation total expensed	$ 2,951	$ 2,113

Income Taxes - Additional Infor

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Income Tax Disclosure [Abstract]
Income tax benefit	$ 263	$ 300

Segment Reporting - Reportable

Segment Reporting - Reportable Revenues by Geographic Regions (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Total revenue	$ 67,400	$ 38,380
United States
Segment Reporting Information [Line Items]
Total revenue	63,804	35,573
Rest of World
Segment Reporting Information [Line Items]
Total revenue	1,313	775
Europe
Segment Reporting Information [Line Items]
Total revenue	2,283	2,032
Testing services
Segment Reporting Information [Line Items]
Total revenue	59,281	31,442
Testing services | United States
Segment Reporting Information [Line Items]
Total revenue	59,021	31,329
Testing services | Rest of World
Segment Reporting Information [Line Items]
Total revenue	260	113
Product
Segment Reporting Information [Line Items]
Total revenue	5,778	4,695
Product | United States
Segment Reporting Information [Line Items]
Total revenue	2,495	2,061
Product | Rest of World
Segment Reporting Information [Line Items]
Total revenue	1,031	632
Product | Europe
Segment Reporting Information [Line Items]
Total revenue	2,252	2,002
Digital And Other
Segment Reporting Information [Line Items]
Total revenue	2,341	2,243
Digital And Other | United States
Segment Reporting Information [Line Items]
Total revenue	2,288	2,183
Digital And Other | Rest of World
Segment Reporting Information [Line Items]
Total revenue	22	30
Digital And Other | Europe
Segment Reporting Information [Line Items]
Total revenue	$ 31	$ 30

Segment Reporting - Long-Lived

Segment Reporting - Long-Lived Assets Consisting of Property and Equipment, Net by Geographic Regions (Detail) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Segment Reporting Information [Line Items]
Long-lived assets	$ 11,398	$ 10,704
United States
Segment Reporting Information [Line Items]
Long-lived assets	10,700	9,888
Europe
Segment Reporting Information [Line Items]
Long-lived assets	302	351
Rest of World
Segment Reporting Information [Line Items]
Long-lived assets	$ 396	$ 465