<PAGE>
<TABLE>
<CAPTION>
- -------- UNITED STATES SECURITIES AND EXCHANGE COMMISSION -----------------------------
FORM 3 WASHINGTON, D.C. 20549 OMB APPROVAL
- -------- -----------------------------
INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES OMB Number: 3235-0104
Expires: September 30, 1998
Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Estimated average burden
Section 17(a) of the Public Utility Holding Company Act of 1935 or hours per response: 0.5
(Print or Type Responses) Section 30(f) of the Investment Company Act of 1940 -----------------------------
- ------------------------------------------------------------------------------------------------------------------------------------
<S><C>
1. Name and Address of Reporting Person* 2. Date of Event Re- 4. Issuer Name AND Ticker or Trading Symbol
The Bay City Capital Fund I, L.P. ("BCC") quiring Statement Medarex, Inc.
c/o Bay City Capital LLC (Month/Day/Year) Nasdaq Trading Symbol: MEDX
- ------------------------------------------------- ------------------------------------------------------------
(Last) (First) (Middle) (06/10/98) 5. Relationship of Reporting Person(s) 6. If Amendment, Date
----------------------- to Issuer (Check all applicable) of Original
3. IRS or Social Se- Director XX 10% Owner (Month/Day/Year)
curity Number of ---- ----
750 Battery Street, Suite 600 Reporting Person Officer (give Other (specify ---------------------
- ------------------------------------------------- (Voluntary) title below) below) 7. Individual or
(Street) ---- ---- Joint/Group Filing
(Check Applicable
Line)
--------------------------- Form filed by One
XX Reporting Person
---
Form filed by
More than One
Reporting Person
San Francisco, California 94111 ---
- ------------------------------------------------------------------------------------------------------------------------------------
(City) (State) (Zip) TABLE I -- NON-DERIVATIVE SECURITIES BENEFICIALLY OWNED
- ------------------------------------------------------------------------------------------------------------------------------------
1. Title of Security 2. Amount of Securities 3. Ownership 4. Nature of Indirect Beneficial
(Instr. 4) Beneficially Owned Form: Direct Ownership (Instr. 5)
(Instr. 4) (D) or Indirect
(I) (Instr. 5)
- ------------------------------------------------------------------------------------------------------------------------------------
Common Stock Up to 2,777,777 shares. I Assuming 6,579,629 shares are
- ------------------------------------------------------------------------------------------------------------------------------------
issued to BCC Acquisition I
- ------------------------------------------------------------------------------------------------------------------------------------
LLC, BCC would have a 42.22%
- ------------------------------------------------------------------------------------------------------------------------------------
proportional interest in the
- ------------------------------------------------------------------------------------------------------------------------------------
profits and capital account
- ------------------------------------------------------------------------------------------------------------------------------------
of BCC Acquisition I LLC.
- ------------------------------------------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------------------------------------------
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. (Over)
* If the form is filed by more than one reporting person, SEE Instruction 5(b)(v). SEC 1473 (7-97)
POTENTIAL PERSONS WHO ARE TO RESPOND TO THE COLLECTION OF INFORMATION CONTAINED IN THIS FORM ARE NOT REQUIRED
TO RESPOND UNLESS THE FORM DISPLAYS A CURRENTLY VALID OMB CONTROL NUMBER.
</TABLE>
<PAGE>
<TABLE>
<CAPTION>
FORM 3 (CONTINUED) TABLE II -- DERIVATIVE SECURITIES BENEFICIALLY OWNED (E.G., PUTS, CALLS, WARRANTS, OPTIONS, CONVERTIBLE
SECURITIES)
- ------------------------------------------------------------------------------------------------------------------------------------
<S><C>
1. Title of Derivative Security 2. Date Exer- 3. Title and Amount of Securities 4. Conver- 5. Owner- 6. Nature of Indirect
(Instr. 4) cisable and Underlying Derivative Security sion or ship Beneficial
Expiration (Instr. 4) Exercise Form of Ownership
Date Price of Deriv- (Instr. 5)
(Month/Day/ Deri- ative
Year) vative Security:
-------------------------------------------------- Security Direct
Amount (D) or
Date Expir- of Indirect
Exer- ation Title Number (I)
cisable Date of
Shares (Instr. 5)
- ------------------------------------------------------------------------------------------------------------------------------------
Warrant (06/10/98) (06/10/05) Common Stock Up to 339,431 $10.00 per share I Assuming 6,579,629
- ------------------------------------------------------------------------------------------------------------------------------------
shares are issued to
- ------------------------------------------------------------------------------------------------------------------------------------
BCC Acquisition I
- ------------------------------------------------------------------------------------------------------------------------------------
LLC, BCC would have
- ------------------------------------------------------------------------------------------------------------------------------------
a 42.22% proportional
- ------------------------------------------------------------------------------------------------------------------------------------
interest in the
- ------------------------------------------------------------------------------------------------------------------------------------
profits and capital
- ------------------------------------------------------------------------------------------------------------------------------------
account of BCC
- ------------------------------------------------------------------------------------------------------------------------------------
Acquisition I LLC.
- ------------------------------------------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------------------------------------------
- ------------------------------------------------------------------------------------------------------------------------------------
Explanation of Responses:
THIS FILING SHALL NOT BE DEEMED AN ADMISSION THAT THE BAY CITY CAPITAL FUND I, L.P. PRESENTLY IS, FOR PURPOSES OF SECTION 16 OF
THE ACT OR OTHERWISE, THE BENEFICIAL OWNER OF ANY EQUITY.
/s/ Roger H. Salquist, Manager
------------------------------------- ----------------------
**Intentional misstatements or omissions of facts constitute Federal **Signature of Reporting Person Date
Criminal Violations. SEE 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient,
SEE Instruction 6 for procedure.
Potential persons who are to respond to the collection of information contained in this form are not
required to respond unless the form displays a currently valid OMB Number. Page 2
SEC 1473 (7-97)
</TABLE>
