Consolidated Statements of Cash Flows Years Ended December 31, 2001 2000 1999 (in thousands of dollars) Cash flows from operating activities: Net loss $ (17,464) $ (18,788) $(11,296) Adjustments to reconcile net loss to net cash provided by (used in) operating activities: Depreciation and amortization 647 343 412 Acquired in-process research and development — 4,969 — Non-cash compensation related to stock options 732 1,036 217 Issuance of common stock to acquire minority interest of Theracell, Inc. — — 136 Other — — 13 Changes in operating assets and liabilities: Prepaid expenses, receivables and other current assets (955) 20 (575) Accounts payable (410) (931) 438 Accrued clinical trials and other liabilities 1,711 188 (200) Deferred contract revenue 2,000 — — Net cash used in operating activities (13,739) (13,163) (10,855) Cash flows from investing activities: Purchases of property and equipment, net (254) (374) (185) Investment in other companies (600) — — Purchases of marketable securities (72,733) (167,355) — Proceeds from maturities of marketable securities 55,750 51,550 — Proceeds from sales of marketable securities 16,127 19,273 — Net cash used in investing activities (1,710) (96,906) (185) Cash flows from financing activities: Issuance of common stock, net 921 83,915 45,839 Net cash provided by financing activities 921 83,915 45,839 Net increase (decrease) in cash and cash equivalents (14,528) (26,154) 34,799 Cash and cash equivalents at beginning of year 20,300 46,454 11,655 Cash and cash equivalents at end of year 5,772 20,300 46,454 Marketable securities at end of year 99,279 97,223 — Cash, cash equivalents and marketable securities at end of year $105,051 $ 117,523 $ 46,454 Schedule of non-cash transaction: Issuance of common stock to acquire technology, net $ — $ 3,522 $ — See accompanying notes. Twenty-One