Vice President, Business Development Employment Agreement

LA JOLLA PHARMACEUTICAL COMPANY LETTERHEAD]


October 29, 1998


Mr. William J. Welch 4927 Riding Ridge Road San Diego, CA 92130


Dear Bill,


On behalf of La Jolla Pharmaceutical Company, I am pleased to offer you the position of Vice President, Business Development reporting to me in my position as CEO. Upon joining the Company, as a regular employee on October 29, 1998 La Jolla Pharmaceutical Company will provide you base compensation at an annual rate of $160,000. Your compensation will be payable biweekly less payroll deductions and all required withholdings, effective your start date. You will also be eligible to participate in the discretionary Executive Bonus Plan based on a combination of subjective and objective factors, including personal and corporate performance goals, on a pro-rated basis. Please note that there are no bonus guarantees.


You will also receive a one time net signing bonus of $12,500, which will be grossed up to include applicable withholdings and payable by separate check at the end of ninety (90) days of regular full time employment at La Jolla Pharmaceutical Company


In addition, La Jolla Pharmaceutical Company will recommend to the Board of Directors that the Company grant you an incentive stock option to buy up to 60,000 shares of LJP common stock in accordance with the Company's stock option plan, with an exercise price equal to the closing price on the day you start with the company and vesting over 5 years at 20% per year.


Beginning the first of the month following your start date you are eligible for the company's vacation, sick leave, holidays, medical, dental and vision benefits as in effect from time to time. Details about these and other employee benefit plans are available for your review.


2


William Welch October 29, 1998 Page 2


As a La Jolla Pharmaceutical Company employee, you will be expected to abide by the Company's rules and regulations, in accordance with our standard employment practices. You will be required to sign an agreement covering Company Confidential Information and Inventions.


You may terminate your employment with La Jolla Pharmaceutical Company at any time and for any reason whatsoever, simply by notifying La Jolla Pharmaceutical Company. Likewise, La Jolla Pharmaceutical Company may terminate your employment at any time whatsoever, with or without cause or advance notice and without any obligation to provide any severance benefits except as set forth in Attachment A or as otherwise agreed by notifying La Jolla Pharmaceutical Company in writing. Since La Jolla Pharmaceutical Company standard policy does not provide for agreements guaranteeing employment for any specific period of time, this offer is not intended to be construed as an employment contract or a guarantee of benefits.


The employment terms in this letter supersede any other agreements or promises made to you by anyone, whether oral or written. As required by law this offer is subject to satisfactory proof of your right to work in the United States.


To accept this offer of employment under the terms described above, please sign both copi ...