Canadian Employee Stock Purchase Plan

QuickLinks -- Click here to rapidly navigate through this document

Exhibit 4.2

As of May 1, 2002


ABGENIX, INC.

CANADIAN EMPLOYEE STOCK PURCHASE PLAN


The following constitute the provisions of the Canadian Employee Stock Purchase Plan of Abgenix, Inc.

1. Purpose. The purpose of the Plan is to provide employees of the Company's Designated Subsidiaries with an opportunity to purchase Common Stock of the Company through accumulated payroll deductions.

2. Definitions. (a) "Administrator" has the meaning set out in Section 14 of this Plan.

(b) "Board" shall mean the Board of Directors of Abgenix, Inc.

(c) "Code" shall mean the Internal Revenue Code of 1986 of the United States of America, as amended.

(d) "Common Stock" shall mean the Common Stock of the Company.

(e) "Company" shall mean Abgenix, Inc.

(f) "Compensation" shall mean all base straight time gross earnings, overtime, commissions, incentive payments, bonuses and other cash compensation.

(g) "Designated Subsidiary" shall mean Abgenix Biopharma Inc. and any Subsidiary which has been designated by the Board from time to time in its sole discretion as eligible to participate in the Plan.

(h) "Employee" shall mean any individual who is (1) an employee in Canada for tax purposes of a Designated Subsidiary; or (2) an individual who is an employee of a Designated Subsidiary and is not resident in Canada for tax purposes but is designated by the Administrator as an "Employee" for the purpose of this Plan; and whose customary employment with the Designated Subsidiary is at least twenty (20) hours per week and more than five (5) months in any calendar year. For purposes of the Plan, the employment relationship shall be treated as continuing intact while the individual is on sick leave or other leave of absence approved by the Designated Subsidiary. Where the period of leave exceeds 90 days and the individual's right to reemployment is not guaranteed either by statute or by contract, for the purposes of the Plan, the employment relationship shall be deemed to have terminated on the 91st day of such leave.

(i) "Enrollment Date" shall mean the first day of each Offering Period.

(j) "Exercise Date" shall mean the last day of each Purchase Period.

(k) "Fair Market Value" shall mean, as of any date, the value of a share of Common Stock determined as follows:

(i) If the Common Stock is listed on any established stock exchange or a national market system, including without limitation the Nasdaq National Market or The Nasdaq SmallCap Market of The Nasdaq Stock Market, its Fair Market Value shall be the closing sales price for such stock (or the closing bid, if no sales were reported) as quoted on such exchange or system for the last market Trading Day on the date of such determination, as reported in The Wall Street Journal or such other source as the Administrator deems reliable; or (ii) If the Common Stock is regularly quoted by a recognized securities dealer but selling prices are not reported, its Fair Market Value shall be the mean of the closing bid and asked prices for the Common Stock on the date of such determination, as reported in The Wall Street Journal or such other source as the Administrator deems reliable; or

(iii) In the absence of an established market for the Common Stock, the Fair Market Value thereof shall be such amount as is determined in good faith by the Administrator to be the fair market value of such share.
(l) "Offering Period" shall mean the period of approximately twenty-four (24) months during which an Option granted pursuant to the Plan may be exercised, commencing on May 1 or November 1 of each year and terminating on the last day in the period ending twenty-four months later; provided, however, that the first Offering Period under the Plan shall commence on May 1, 2002 or such period with commencement date and duration as changed by the Board pursuant to Section 4 of this Plan.

(m) "Option" has the meaning set out in Section 7 hereunder.

(n) "Plan" shall mean this Canadian Employee Stock Purchase Plan.

(o) "Purchase Period" shall mean a period of six (6) months within an Offering Period. The Purchase Periods for the first offering Period shall be as follows:

May 1, 2002 through October 31, 2002

November 1, 2002 through April 30, 2003

May 1, 2003 through October 31, 2003

November 1, 2003 through April 30, 2004 (p) "Purchase Price" shall mean the Fair Market Value of a Share of Common Stock on the Enrollment Date or on the Exercise Date, whichever is lower.

(q) "Reserves" shall mean the aggregate number of shares of Common Stock covered by each Option under the Plan which have not yet been exercised and the number of shares of Common Stock which have been authorized for issuance under the Plan but not yet placed under Option.

(r) "Subsidiary" shall mean a corporation, domestic or foreign, of which more than 50% of the voting shares are held by the Company or a Subsidiary, whether or not such corporation now exists or is hereafter organized or acquired by the Company or a Subsidiary.

(s) "Trading Day" shall mean a day on which U.S. stock exchanges and the Nasdaq System are open for trading.

(t) "U.S. Dollar Equivalent" of a participant's payroll deductions accumulated on or before a certain date shall mean such participant's payroll deductions converted into U.S. dollars based on the noon buying rate in New York City for cable transfers in Canadian dollars as certified for customs purposes by the Federal Reserve Bank of New York on the third business day in New York immediately before the relevant date.

3. Eligibility. (a) Any Employee who shall be employed by a Designated Subsidiary on a given Enrolment Date shall be eligible to participate in the Plan, subject to the requirements of Section 5(a); provided however that eligible Employees may not participate in more than one Offering Period at a time and may not participate in the Company's 1998 Employee Stock Purchase Plan.

2 (b) Any provisions of the Plan to the contrary notwithstanding, no Employee shall be granted an Option under the Plan (i) to the extent that, immediately after the grant, such Employee (or any other person whose stock would be attributed to such Employee pursuant to Section 424(d) of the Code) would own capital stock of the Company and/or hold outstanding Options to purchase such stock possessing five percent (5%) or more of the total combined voting power or value of all classes of the capital stock of the Company, or (ii) to the extent that his or her rights to purchase stock under all employee stock purchase plans of the Company and its subsidiaries accrues at a rate which exceeds Twenty-Five Thousand U.S. Dollars (US$25,000) worth of stock of the Company (determined at the Fair Market Value of the shares at the time such Option is granted) for each calendar year in which such Option is outstanding at any time.

4. Offering Periods and Purchase Periods. (a) Offering Periods . The Plan shall be implemented by consecutive, overlapping Offering Periods with a new Offering Period commencing on May 1 and November 1 each year, or on such other date as the Board shall determine, and continuing thereafter until terminated in accordance with Section 20 hereof; provided, however, that the first Offering Period under the Plan shall commence on May 1, 2002. The Board shall have the power to change the duration of Offering Periods (including the commencement dates thereof) with respect to future offerings without approval from Employees or participants under the Plan if such change is announced at least five (5) days prior to the scheduled beginning of the first Offering Period to be affected thereafter.

(b) Purchase Periods . Each Offering Period shall consist of four (4) consecutive Purchase Periods of approximately six (6) month's duration. The last day of each Purchase Period shall be the Exercise Date for such Purchase Period. A Purchase Period commencing on May 1 shall end on the next October 31. A Purchase Period commencing on November 1 shall end on the next April 30. Notwithstanding the foregoing, the Administrator may change the duration and/or frequency of any Purchase Period in its sole discretion, upon the commencement of any new Purchase Period, subject to all applicable federal and provincial laws.

5. Participation. (a) An Employee may become a participant in the Plan by completing a subscription agreement authorizing payroll deductions in the form of Exhibit A to this Plan and filing it with the Company or the Designated Subsidiary's payroll office prior to the applicable Enrolment Date.

(b) Payroll deductions for a participant shall commence on the first payroll following the Enrolment Date and shall end when terminated by the participant as provided in Section 10 hereof.

6. Payroll Deductions. (a) At the time a participant files his or her subscription agreement, he or she shall elect in the subscription agreement to have payroll deductions made on each pay day during the Offering Period in an amount being a whole percentage not exceeding fifteen percent (15%) of the Compensation which he or she is entitled to receive on each pay day during the Offering Period.

(b) All payroll deductions made for a participant shall be credited to his or her account under the Plan and shall be withheld in whole percentages only. A participant may not make any additional payments into such account.

3 (c) A participant may either (i) discontinue his or her participation in the Plan as provided in Section 10 hereof, or, (ii) increase or decrease (including to zero percent (0%)) the rate of his or her payroll deductions during the Offering Period without discontinuing his or her participation in the Plan by completing and filing with the Company a new subscription agreement authorizing a change in payroll deduction rate. The Administrator may, in its discretion, limit the number of participation rate changes during any Offering Period. The change in rate shall be effective with the first full payroll period following five (5) business days after the Company's receipt of the new subscription agreement unless the Company elects to process a given change in participation more quickly. A participant's subscription agreement shall remain in effect for successive Offering Periods unless changed in accordance with thi ...