Management’s Discussion and Analysis of Financial Condition  and Results of Operations (continued) controlled rate. We will also continue to identify new technolo- gies and/or product candidates for possible in-licensing or acquisition. Accordingly, we expect to incur operating losses for the foreseeable future. We cannot assure you that we will ever achieve profitable operations. Comparison of Years Ended December 31, 2000 and 1999 Revenues in 2000 were $1.9 million compared to $0.3 million for 1999, an increase of $1.6 million. The increase in revenue is primarily due to our corporate partnership with Schering for the development and commercialization of Spheramine for the treatment of Parkinson’s disease. Ongoing research and development expenses for 2000 were $16.7 million, compared to $9.4 million for 1999, an increase  of $7.3 million. The planned increase in ongoing research  and development expenditures from 1999 to 2000 was a  result of the expansion of our randomized, placebo-controlled Phase III clinical study of CeaVac in Dukes D colorectal cancer, commencement of our Phase I/II clinical study of Spheramine in Parkinson’s disease, advancement of our pre-clinical devel- opment programs and increased manufacturing and devel- opment activity for all of our product candidates. Also in  year 2000, we recorded a $5.0 million acquired in-process research and development expense in connection with  the acquisition of gallium maltolate, a novel and proprietary agent for the potential treatment of cancer and other con- ditions, including HIV infection. The entire purchase price  was charged to acquired in-process research and development on the acquisition date in accordance with generally accepted accounting principles. See Note 8 to the Consolidated Finan- cial Statements. General and administrative expenses for 2000 were $4.1 mil- lion compared to $2.8 million for 1999, an increase of $1.3 million. The increase was in support of our expanded clinical operations, infrastructure development and non-cash com- pensation charges related to stock options. Other income, net, for 2000 was $5.1 million compared to $0.7 million for 1999, an increase of $4.4 million. Other income, net, for 2000 and 1999 primarily consisted of interest income. The increase in interest income resulted from a significantly larger cash and marketable securities position in 2000. As a result of the foregoing, we had a net loss of $18.8 million in 2000 compared to a net loss of $11.3 million in 1999. Uses of cash in operating activities were primarily to fund product development programs and administrative expenses. We have entered into various agreements with research insti- tutions, universities, and other entities for the performance of research and development activities and for the acquisition  of licenses related to those activities. Certain of the licenses require us to pay royalties on future product sales, if any.  In addition, in order to maintain license and other rights  while products are under development, we must comply with customary licensee obligations, including the payment of patent-related costs and meeting project-funding milestones. In January 1999, we completed a private placement of 2.3 million shares of our common stock for net proceeds of $5.8 million, after deducting fees and commissions and other expenses of the offering. In October 1999, we called for the redemption of our then out- standing Class A Warrants. Rather than surrendering the war- rants for redemption, warrant holders exercised the option to purchase our common stock and resulted in 7.1 million Class A Warrants, or 99.4%, being exercised with net proceeds to Titan of $39.4 million, after deducting advisory fees and other related expenses. In March 2000, we completed a private placement of 1.2 million shares of our common stock for net proceeds of approximately $38.8 million, after deducting fees and com- missions and other expenses of the offering. In November 2000, we completed a private placement of 1.2 million shares of our common stock for net proceeds of approximately $40.9 million, after deducting fees and commis- sions and other expenses of the offering. We have funded our operations since inception primarily through sales of our securities, as well as proceeds from war- rant and option exercises, corporate licensing and collabora- tive agreements, and government-sponsored research grants. Sixteen Liquidity and Capital Resources 2001 2000 1999 (in thousands) As of December 31: Cash, cash equivalents and  marketable securities $105,051 $117,523 $46,454 Working capital 100,193 115,386 45,128 Current ratio 18:1 48:1 26:1 Year Ended December 31: Cash used in operating  activities (13,739) (13,163) (10,855) Cash used in investing  activities (1,710) (96,906) (185) Cash provided by financing  activities 921 83,915 45,839