SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES AND USE OF ESTIMATES

The preparation of financial statements in conformity with GAAP requires our management to make informed estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses. However, actual values may materially differ, since estimates are inherently uncertain. On an on-going basis, our management evaluates its estimates and assumptions, including those related to (i) gross-to-net revenue adjustments; (ii) the timing of revenue recognition; (iii) the collectability of customer accounts; (iv) whether the cost of inventories can be recovered; (v) the fair value of goodwill and intangible assets; (vi) the realization of tax assets and estimates of tax liabilities; (vii) the likelihood of payment and value of contingent liabilities; (viii) the fair value of investments; (ix) the valuation of stock options and the periodic expense recognition of stock-based compensation; and (x) the potential outcome of ongoing or threatened litigation.

The estimates and assumptions that most significantly impact the presented amounts within these Consolidated Financial Statements are further described below:

(i) Revenue Recognition

(a) Product Sales: We sell our products to wholesalers/distributors (i.e., our customers), except for our U.S. sales of ZEVALIN in which case the end-user (i.e., clinic or hospital) is our customer. Our wholesalers distributors in turn sell our products directly to clinics, hospitals, and private oncology-based practices. Revenue from product sales is recognized when title and risk of loss have transferred to our customer, and the following additional criteria are met:


(1)	appropriate evidence of a binding arrangement exists with our customer;


(2)	price is substantially fixed and determinable;


(3)	collection from our customer is reasonably assured;


(4)	our customer’s obligation to pay us is not contingent on resale of the product;


(5)	we do not have significant continued performance obligations to our customer; and


(6)	we have a reasonable basis to estimate returns.

Our gross revenue is reduced by our gross-to-net (“GTN”) estimates each period, resulting in our reported “product sales, net” in the accompanying Consolidated Statements of Operations. We defer revenue recognition in full if these estimates are not reasonably determinable at the time of sale. These estimates are based upon information received from external sources (such as written and oral information obtained from our customers with respect to their period-end inventory levels and their sales to end-users during the period), in combination with management’s informed judgments. Due to the inherent uncertainty of estimates, the actual amount we incur may be materially different than our GTN estimates, and require prospective revenue adjustments in periods after the initial sale was recorded.

Our GTN estimates are comprised of the following categories:

Product Returns Allowances: Our FUSILEV, MARQIBO, and BELEODAQ customers are permitted to return purchased products beginning at its expiration date and within six months thereafter. Returned product is generally not resold. Returns for expiry of ZEVALIN and FOLOTYN are not contractually, or customarily, allowed. We estimate expected returns based on historical return rates.

Government Chargebacks: Our products are subject to pricing limits under certain federal government programs (e.g., Medicare and 340B Drug Pricing Program). Qualifying entities (i.e., end-users) purchase products from our customers at their qualifying discounted price. The chargeback amount we incur represents the difference between our contractual sales price to our customer, and the end-user’s applicable discounted purchase price under the government program. There may be significant lag time between our reported net product sales and our receipt of the corresponding government chargeback claims from our customers.

Prompt Pay Discounts: Discounts for prompt payment are estimated at the time of sale, based on our eligible customers’ prompt payment history and the contractual discount percentage.

Commercial Rebates: Commercial rebates are based on (i) our estimates of end-user purchases through a group purchasing organization ("GPO"), (ii) the corresponding contractual rebate percentage tier we expect each GPO to achieve, and (iii) our estimates of the impact of any prospective rebate program changes made by us.

Medicaid Rebates: Our products are subject to state government-managed Medicaid programs, whereby rebates are issued to participating state governments. These rebates arise when a patient treated with our product is covered under Medicaid, resulting in a discounted price for our product under the applicable Medicaid program. Our Medicaid rebate accrual calculations require us to project the magnitude of our sales, by state, that will be subject to these rebates. There is a significant time lag in us receiving rebate notices from each state (generally several months or longer after our sale is recognized). Our estimates are based on our historical claim levels by state, as supplemented by management’s judgment.

Distribution, Data, and GPO Administrative Fees: Distribution, data, and GPO administrative fees are paid to authorized wholesalers/distributors of our products (except for U.S. sales of ZEVALIN) for various commercial services, including: contract administration, inventory management, delivery of end-user sales data, and product returns processing. These fees are based on a contractually-determined percentage of our applicable sales.

(b) License Fees: We recognize revenue for our licensing of intellectual property to third-parties (out-licenses), based on the contractual terms of each agreement and our application of pertinent GAAP. This revenue may be associated with upfront license fees, milestone payments from our licensees’ sales or regulatory achievements, and royalties from our licensees’ sales in applicable territories.

(c) Service Revenue: We receive fees from third-parties under certain arrangements for our research and development activities, sales and marketing activities, clinical trial management, and supply chain services. Payment may be triggered by the successful completion of a phase of development, results from a clinical trial, regulatory approval events, or completion of product or service delivery in our capacity as an agent or principal in such arrangement. We recognize revenue when the corresponding milestone is achieved, or the revenue is otherwise earned and due to us through our on-going activities.

(d) New Revenue Recognition Standard: On April 1, 2015, the FASB voted for a one-year deferral of the effective date of the new revenue recognition standard, ASU No. 2014-09, Revenue from Contracts with Customers (Topic 606) (“ASU 2014-09”). ASU 2014-09 is now effective for us beginning January 1, 2018, requiring revenue recognition in a manner that reasonably reflects the delivery of our goods or services to customers in return for expected consideration. To achieve this core principle, the guidance provides the following steps: (1) identify the contract(s) with a customer; (2) identify the performance obligations in the contract; (3) determine the transaction price; (4) allocate the transaction price to the performance obligations in the contract; and (5) recognize revenue when (or as) the entity satisfies a performance obligation.

We intend to apply the cumulative effect transition method of ASU 2014-09, and we continue to evaluate the impact of this new standard to our current revenue recognition models for product sales, license fees, and service revenue, as described above.

(ii) Cash and Cash Equivalents

Cash and cash equivalents consist of bank deposits and highly liquid investments with maturities of three months or less from the purchase date.

(iii) Marketable Securities

Our marketable securities consist of our holdings in mutual funds and bank certificates of deposit. Since we classify these securities as “available-for-sale” under applicable GAAP, any unrealized gains or losses from their change in value is reflected in “unrealized (loss) gain on securities” on the accompanying Consolidated Statements of Comprehensive Loss. Realized gains and losses on available-for-sale securities are included in “other (expense) income, net” on the accompanying Consolidated Statements of Operations.

(iv) Accounts Receivable

Our accounts receivables are derived from our product sales, license fees, and service revenue, and do not bear interest. The allowance for doubtful accounts is management’s best estimate of the amount of probable credit losses in existing accounts receivable. Account balances are charged off against the allowance after appropriate collection efforts are exhausted.

(v) Inventories

We value inventory at the lower of (i) the actual cost of its purchase or manufacture, or (ii) its current market value. Inventory cost is determined on the first-in, first-out method (FIFO). We regularly review our inventory quantities in process of manufacture and on hand. When appropriate, we record a provision for obsolete and excess inventory to derive its new cost basis, which takes into account our sales forecast by product and corresponding expiry dates.

Direct and indirect manufacturing costs related to the production of inventory prior to U.S. Food and Drug Administration ("FDA") approval are expensed through “research and development,” rather than being capitalized to inventory cost.

(vi) Property and Equipment

Our property and equipment is stated at historical cost, and is depreciated on a straight-line basis over an estimated useful life that corresponds with its designated asset category. We evaluate the recoverability of “long-lived assets” (which includes property and equipment) whenever events or changes in circumstances in our business indicate that the asset’s carrying amount may not be recoverable through on-going operations.

(vii) Goodwill and Intangible Assets

Our goodwill represents the excess of our business acquisition cost over the estimated fair value of the net assets acquired in the corresponding transaction. Goodwill has an indefinite accounting life and is therefore not amortized. Instead, goodwill is evaluated for impairment on an annual basis (as of each October 1st), unless we identify impairment indicators that would require earlier testing.

We evaluate the recoverability of indefinite-lived intangible assets at least annually, or whenever events or changes in our business indicate that an intangible asset’s (whether indefinite or definite-lived) carrying amount may not be recoverable. Such circumstances could include, but are not limited to the following:

(a) a significant decrease in the market value of an asset;

(b) a significant adverse change in the extent or manner in which an asset is used; or

Intangible assets with finite useful lives are amortized over their estimated useful lives on a straight-line basis. We review these assets for potential impairment if/when facts or circumstances suggest that the carrying value of these assets may not be recoverable.

(viii) Stock-Based Compensation

Stock-based compensation expense for equity awards granted to our employees and members of our board of directors is recognized on a straight-line basis over each award's vesting period. Recognized compensation expense is net of an estimated forfeiture rate, representing the percentage of awards that are expected to be forfeited (by termination of employment or service) prior to vesting. We use the Black-Scholes option pricing model to determine the fair value of stock options (as of the date of grant) which carry service conditions for vesting. We use the Monte Carlo valuation model to value equity awards (as of the date of grant) which carry combined market conditions and service conditions for vesting.

The calculation of the fair value of stock options and the recognition of stock-based compensation expense requires uncertain assumptions, including (a) the pre-vesting forfeiture rate of the award, (b) the expected term of the stock option, (c) the stock price volatility over the term of the stock option, and (d) the risk-free interest rate over the term of the stock option.

We estimate forfeiture rates based on our employees’ overall forfeiture history, which we believe will be representative of future results. We estimate the expected term of stock options granted based on our employees’ historical exercise patterns, which we believe will be representative of their future behavior. We estimate the volatility of our common stock on the date of grant based on historical volatility of our common stock for a look-back period that corresponds with the expected term. We estimate the risk-free interest rate based upon the U.S. Treasury yields in effect at award grant, for a period equaling the stock options’ expected term.

(ix) Foreign Currency Translation

We translate the assets and liabilities of our foreign subsidiaries that are stated in their functional currencies (i.e., local operating currencies), to U.S. dollars at the rates of exchange in effect at the reported balance sheet date. Revenues and expenses are translated using the monthly average exchange rates during the reported period. Unrealized gains and losses from the translation of our subsidiaries’ financial statements (that are initially denominated in the corresponding functional currency) are included as a separate component of “accumulated other comprehensive loss” in the Consolidated Balance Sheets.

We record foreign currency transactions, when initially denominated in a currency other than the respective functional currency of our subsidiary, at the prevailing exchange rate on the date of the transaction. Resulting unrealized foreign exchange gains and losses from transactions with third parties are included in “accumulated other comprehensive loss” in the Consolidated Balance Sheets.

Beginning April 1, 2015, all unrealized foreign exchange gains and losses associated with our intercompany loans were included in "accumulated other comprehensive loss" in the Consolidated Balance Sheets, as these loans with our foreign subsidiaries are no longer expected to be settled in the "foreseeable future." For the period January 1, 2015 through March 31, 2015, unrealized foreign exchange gains and losses associated with our intercompany loans were included in "accumulated other comprehensive loss" in the Consolidated Balance Sheets and in "other expense (income), net" in the Consolidated Statements of Operations. In periods prior to January 1, 2015, all unrealized foreign exchange gains and losses associated with intercompany loans were included in “other expense (income), net” in the Consolidated Statements of Operations.

(x) Basic and Diluted Net (Loss) Income per Share

We calculate basic and diluted net (loss) income per share using the weighted average number of common shares outstanding during the periods presented. In periods of a net loss, basic and diluted loss per share are the same. For the diluted earnings per share calculation, we adjust the weighted average number of common shares outstanding to include only dilutive stock options, warrants, and other common stock equivalents outstanding during the period.

(xi) Income Taxes

Deferred tax assets and liabilities are recorded based on the estimated future tax effects of temporary differences between the tax basis of assets and liabilities and amounts reported in the financial statements, as well as operating losses and tax credit carry forwards using enacted tax rates and laws that are expected to be in effect when the differences are expected to reverse. Realization of deferred tax assets is dependent upon future earnings, the timing and amount of which are uncertain.

We have recorded a valuation allowance to reduce our net deferred tax assets, because we believe that, based upon a weighting of positive and negative factors, it is more likely than not that these deferred tax assets will not be realized. If/when we were to determine that our deferred tax assets are realizable, an adjustment to the corresponding valuation allowance would increase our net income in the period that such determination was made.

In the event that we are assessed interest and/or penalties from taxing authorities that have not been previously accrued, such amounts would be included in “Provision for income taxes” within the Consolidated Statements of Operations in the period the notice was received.

(xii) Research and Development Costs

Research and development costs are expensed as incurred, or as certain milestone payments become due, generally triggered by contractual clinical or regulatory events.

(xiii) Fair Value Measurements

We determine measurement-date fair value based on the proceeds that would be received through the sale of the asset, or that we would pay to settle or transfer the liability, in an orderly transaction between market participants. We utilize valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible. Fair value measurements are based on a three-tier hierarchy that prioritizes the inputs used to measure fair value. These tiers include the following:

Level 1: Quoted prices (unadjusted) in active markets for identical assets or liabilities that are publicly accessible at the measurement date.

Level 2: Observable prices that are based on inputs not quoted on active markets, but that are corroborated by market data. These inputs may include quoted prices for similar assets or liabilities or quoted market prices in markets that are not active to the general public.

Level 3: Unobservable inputs are used when little or no market data is available. The fair value hierarchy gives the lowest priority to Level 3 inputs.