Organization and Basis of Presentation	3 Months Ended
Organization and Basis of Presentation	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization and Basis of Presentation	ORGANIZATION AND BASIS OF PRESENTATION Ardelyx, Inc. (the “Company,” “we,” “us” or “our”) is a biopharmaceutical company founded with a mission to discover, develop and commercialize innovative first-in-class medicines that meet significant unmet medical needs. We operate in one business segment, which is the development and commercialization of biopharmaceutical products. Basis of Presentation These condensed financial statements have been prepared in accordance with accounting principles generally accepted in the United States of America (“U.S. GAAP”) and pursuant to the requirements of the Securities and Exchange Commission (“SEC”) for interim reporting. As permitted under those rules and regulations, certain footnotes or other financial information that are normally required by U.S. GAAP have been condensed or omitted. These condensed financial statements have been prepared on the same basis as our most recent annual financial statements and, in the opinion of management, reflect all adjustments, which include only normal recurring adjustments necessary to present fairly our financial position, results of operations, changes in stockholders’ equity, and cash flows for the interim periods presented. The accompanying condensed financial statements and related financial information should be read in conjunction with the audited financial statements and the related notes thereto included in our Annual Report on Form 10-K for the year ended December 31, 2021. The results for the three months ended March 31, 2022 are not necessarily indicative of results to be expected for the entire year ending December 31, 2022, or for any other interim period or future year. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and judgments that affect the amounts reported in the financial statements and accompanying notes thereto. On an ongoing basis, management evaluates its estimates, including those related to recognition of revenue, clinical trial accruals, contract manufacturing accruals, the fair value of assets and liabilities, income taxes and stock-based compensation. Management bases its estimates on historical experience and on various other market-specific and relevant assumptions that management believes to be reasonable under the circumstances. Actual results could materially differ from those estimates. Liquidity As of March 31, 2022, we had cash and investments of approximately $89.7 million. We have incurred operating losses since inception and our accumulated deficit as of March 31, 2022 is $741.0 million. Our current level of cash and investments alone is not sufficient to meet our plans for the next twelve months following the issuance of these financial statements. These factors raise substantial doubt regarding our ability to continue as a going concern for a period of one year from the issuance of these financial statements. We plan to address our operating cash flow requirements with our current cash and investments, cash generated from sales of IBSRELA, our potential receipt of anticipated milestones from our collaboration partners, our ability to access the capital markets, as well as through the implementation of cash preservation activities to reduce or defer discretionary spending. There are no assurances that our efforts to meet our operating cash flow requirements will be successful. If our current cash and investments as well as our plans to meet our operating cash flow requirements are not sufficient to fund necessary expenditures and meet our obligations for at least the next twelve months following the issuance of these financial statements, our liquidity, financial condition and business prospects will be materially affected. These financial statements have been prepared on a going concern basis and do not include any adjustments to the amounts and classification of assets and liabilities that may be necessary in the event that we can no longer continue as a going concern. Summary of Significant Accounting Policies Our significant accounting policies are described in Note 1 to our audited financial statements for the fiscal year ended December 31, 2021, included in our Annual Report on Form 10-K. Our significant accounting policies for the three months ended March 31, 2022 also included the policies discussed below related to accounts receivable, inventory, revenue and cost of revenue for commercial product sales. With the exception of those noted below, there have been no material changes in our significant accounting policies as previously disclosed in our Annual Report on Form 10-K for the fiscal year ended December 31, 2021. Accounts Receivable Accounts receivable is reported net of allowances for returns, chargebacks and contractual discounts offered to our customers. Our estimate of the allowance for doubtful accounts is based on an evaluation of the aging of our receivables. Trade receivable balances are written off against the allowance when it is probable that the receivable will not be collected. To date, we have determined that an allowance for doubtful accounts is not required. As of March 31, 2022 our accounts receivable balance is comprised of $3.8 million from our collaborators and $0.6 million from commercial customers. As of December 31, 2021 our accounts receivable balance was comprised of $0.5 million from our collaborators. Inventory Prior to the regulatory approval of drug product candidates, we incurred expenses for the manufacture of drug product that could potentially be available to support the commercial launch of our products. We began to capitalize inventory costs associated with IBSRELA during the fourth quarter of 2021, when our intent to commercialize IBSRELA was established and we commenced preparation for the commercial launch of IBSRELA, which was when it was determined that the inventory had a probable future economic benefit. Inventory is stated at the lower of cost or estimated net realizable value with cost determined under the first-in first-out method. Inventory costs include third-party contract manufacturing, third-party packaging services, freight, labor costs for personnel involved in the manufacturing process, and indirect overhead costs. We primarily use actual costs to determine the cost basis for inventory. The determination of whether inventory costs will be realizable requires management review of the expiration dates of IBSRELA compared to our forecasted sales. If actual market conditions are less favorable than projected by management, write-downs of inventory may be required, which would be recorded as cost of goods sold in the condensed statement of operations and comprehensive loss. Product Sales, Net We account for our commercial product sales, net in accordance with Topic 606 - Revenue from Contracts with Customers. We received approval from the U.S. Food and Drug Administration (“FDA”) in September 2019 to market IBSRELA, the first and only sodium hydrogen exchanger 3 (“NHE3”) inhibitor for the treatment of irritable bowel syndrome with constipation ("IBS-C") in adults, in the United States ("U.S."). We began selling IBSRELA in the U.S. in March 2022. We distribute our products principally through a limited number of distributors and specialty pharmacy providers (collectively, our "Customers"). Our Customers subsequently sell our products to pharmacies and patients. Separately, we enter into arrangements with third parties that provide for government-mandated and privately-negotiated rebates, chargebacks and discounts. Revenue from product sales is recognized when our performance obligations are satisfied, which is when Customers obtain control of our product and occurs upon delivery. Reserves for Variable Consideration Revenues from product sales are recorded at the net sales price (transaction price), which includes estimates of variable consideration, including rebates, discounts, patient copay assistance programs, and estimated product returns. These estimates are based on the amounts earned or to be claimed for related sales and are classified as reductions of accounts receivable if the amount is payable to our Customers or a current liability if the amount is payable to a party other than a Customer. Where appropriate, these estimates are based on factors such as industry data and forecasted customer buying and payment patterns, our historical experience, current contractual and statutory requirements, specific known market events and trends. Overall, these reductions to gross sales reflect our best estimates of the amount of consideration to which we are entitled based on the terms of the contract. Variable consideration is included in the transaction price only to the extent that it is probable that a significant reversal in the amount of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is subsequently resolved. Actual amounts of consideration ultimately received may differ from our estimates. If actual results in the future vary from our estimates, we adjust these estimates, which would affect product revenue and earnings in the period such variances become known. As we gain more historical experience, estimates will be more heavily based on the expected utilization from historical data we have accumulated since the IBSRELA product launch. Rebates: Rebates include mandated discounts under the Medicaid Drug Rebate Program ("Medicaid") and the Medicare Coverage Gap Program ("Medicare"). Rebates are amounts owed after the final dispensing of products to a benefit plan participant and are based upon contractual agreements or legal requirements with the public-sector benefit providers. These estimates for rebates are recorded in the same period the related gross revenue is recognized, resulting in a reduction of product revenue and the establishment of a current liability which is included in accrued expenses on the condensed balance sheets. We estimate our Medicaid and Medicare rebates based upon the estimated payor mix, and statutory discount rates. Our estimates for payor mix are guided by payor information received from specialty pharmacies, expected utilization for specialty distributor sales to pharmacies, and available industry payor information. Chargebacks: Chargebacks are discounts that occur when contracted purchasers purchase directly from our specialty distributors at a discounted price. The specialty distributor, in turn, charges back the difference between the price initially paid to us by the specialty distributor and the discounted price paid to the specialty distributor by the contracted purchaser. Amounts for estimated chargebacks are established in the same period that the related gross revenue is recognized, resulting in a reduction of product revenue and accounts receivable. The accrual for specialty distributor chargebacks is estimated based on known chargeback rates, known sales to specialty distributors, and estimated utilization by types of contracted purchasers. Discounts and Fees: Our payment terms are generally 30 to 60 days. Specialty distributors and specialty pharmacies are offered various forms of consideration, including service fees and prompt pay discounts for payment within a specified period. We expect these Customers will earn prompt pay discounts and therefore, we deduct the full amount of these discounts and service fees from product sales when revenue is recognized, resulting in a reduction of product revenue and accounts receivable. Other Reserves: Patients who have commercial insurance may receive co-pay assistance when product is dispensed by pharmacies to patients. We estimate the amount of co-pay assistance provided to eligible patients based on the terms of the program and redemption information provided by third-party claims processing organizations and are recorded in accounts payable, accrued expenses and other current liabilities on the condensed balance sheets. Cost of Revenue Cost of revenue consists of the cost of commercial goods sold to our Customers, international partners under product supply agreements, and royalty expense based on sales of tenapanor. We capitalize inventory costs associated with the production of our products after regulatory approval or when, based on management’s judgment, future commercialization is considered probable and the future economic benefit is expected to be realized. Otherwise, such costs are expensed as research and development. A portion of the costs of IBSRELA units recognized as revenue during the three months ended March 31, 2022 were expensed prior to the fourth quarter of 2021, at which time our intent to commercialize IBSRELA was established and we commenced preparation for the commercial launch of IBSRELA. Cost of revenue includes payments due to AstraZeneca, which under the terms of a termination agreement entered into in 2015 (the "AZ Termination Agreement") is entitled to (i) future royalties at a rate of 10% of net sales of tenapanor or other NHE3 products by us or our licensees, and (ii) 20% of non-royalty revenue received from our collaboration partners as a result of the development and commercialization of tenapanor or certain other NHE3 inhibitors. We have agreed to pay AstraZeneca up to a maximum of $75.0 million in the aggregate for (i) and (ii). We recognize these expenses as cost of revenue when we recognize the corresponding revenue that gives rise to payments due to AstraZeneca. To date, we have recognized an aggregate of $11.7 million as cost of revenue under the AZ Termination Agreement. Recent Accounting Pronouncements New Accounting Pronouncements - Recently Adopted We have adopted no new accounting pronouncements other than those disclosed in our most recent Annual Report on Form 10-K. Recent Accounting Pronouncements Not Yet Adopted There were various accounting standards and interpretations issued recently, none of which are expected to a have a material impact on our financial position, operations or cash flows.