FORM 4
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940
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(Print or Type Responses)
1. Name and Address of Reporting Person *
BVF PARTNERS L P/IL
  2. Issuer Name and Ticker or Trading Symbol
XOMA Corp [XOMA]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
(Last)
(First)
(Middle)
44 MONTGOMERY STREET, 40TH FLOOR
3. Date of Earliest Transaction (Month/Day/Year)
12/14/2018
(Street)

SAN FRANCISCO, CA 94104
4. If Amendment, Date Original Filed(Month/Day/Year)
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1.Title of Security
(Instr. 3)
2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code
(Instr. 8)
4. Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4 and 5)
5. Amount of Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 3 and 4)
6. Ownership Form: Direct (D) or Indirect (I)
(Instr. 4)
7. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V Amount (A) or (D) Price
Common Stock, $0.0075 par value per share (1) 12/17/2018   P   25,000 A $ 14.1917 718,541 D (3)  
Common Stock, $0.0075 par value per share (1)               694,961 D (2)  
Common Stock, $0.0075 par value per share (1)               123,649 D (4)  
Common Stock, $0.0075 par value per share (1)               231,878 I (5) See footnote (5)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 3)
2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code
(Instr. 8)
5. Number of Derivative Securities Acquired (A) or Disposed of (D)
(Instr. 3, 4, and 5)
6. Date Exercisable and Expiration Date
(Month/Day/Year)
7. Title and Amount of Underlying Securities
(Instr. 3 and 4)
8. Price of Derivative Security
(Instr. 5)
9. Number of Derivative Securities Beneficially Owned Following Reported Transaction(s)
(Instr. 4)
10. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 4)
11. Nature of Indirect Beneficial Ownership
(Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Subscription Rights $ 13,000 12/14/2018   X     345.313 11/19/2018 12/14/2018 Series Y Convertible Preferred Stock, $0.05 par value 345.313 $ 0 0 D (2)  
Series Y Convertible Preferred Stock (8) 12/14/2018   X   345.313 (6)     (8)   (8) Common Stock, $0.0075 par value per share 345,313 $ 13,000 345.313 D (2)  
Subscription Rights $ 13,000 12/14/2018   X     224.813 11/19/2018 12/14/2018 Series Y Convertible Preferred Stock, $0.05 par value 224.813 $ 0 0 D (3)  
Series Y Convertible Preferred Stock (8) 12/14/2018   X   224.813 (6)     (8)   (8) Common Stock, $0.0075 par value per share 224,813 $ 13,000 224.813 D (3)  
Series Y Convertible Preferred Stock (8) 12/18/2018   X   310.646 (7)     (8)   (8) Common Stock, $0.0075 par value per share 310,646 $ 13,000 655.959 D (2)  
Series Y Convertible Preferred Stock (8) 12/18/2018   X   372 (7)     (8)   (8) Common Stock, $0.0075 par value per share 372,000 $ 13,000 596.813 D (3)  
Series X Convertible Preferred Stock (9)               (9)   (9) Common Stock, $0.0075 par value per share 2,313,000   2,313 D (2)  
Series X Convertible Preferred Stock (9)               (9)   (9) Common Stock, $0.0075 par value per share 1,506,000   1,506 D (3)  
Series X Convertible Preferred Stock (9)               (9)   (9) Common Stock, $0.0075 par value per share 412,000   412 D (4)  
Series X Convertible Preferred Stock (9)               (9)   (9) Common Stock, $0.0075 par value per share 772,000   772 I (5) See footnote (5)

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
BVF PARTNERS L P/IL
44 MONTGOMERY STREET
40TH FLOOR
SAN FRANCISCO, CA 94104
    X    
BIOTECHNOLOGY VALUE FUND L P
44 MONTGOMERY STREET
40TH FLOOR
SAN FRANCISCO, CA 94104
      See Explanation of Responses
BIOTECHNOLOGY VALUE FUND II LP
44 MONTGOMERY STREET
40TH FLOOR
SAN FRANCISCO, CA 94104
      See Explanation of Responses
Biotechnology Value Trading Fund OS LP
P.O. BOX 309 UGLAND HOUSE
GRAND CAYMAN, E9 KY1-1104
      See Explanation of Responses
BVF Partners OS Ltd.
P.O. BOX 309 UGLAND HOUSE
GRAND CAYMAN, E9 KY1-1104
      See Explanation of Responses
BVF INC/IL
44 MONTGOMERY STREET
40TH FLOOR
SAN FRANCISCO, CA 94104
    X    
LAMPERT MARK N
44 MONTGOMERY STREET
40TH FLOOR
SAN FRANCISCO, CA 94104
    X    

Signatures

 BVF Partners L.P., By: BVF Inc., its general partner, By: /s/ Mark N. Lampert, President   12/19/2018
**Signature of Reporting Person Date

 Biotechnology Value Fund, L.P., By: BVF Partners L.P., its general partner, By: BVF Inc., its general partner, By: /s/ Mark N. Lampert, President   12/19/2018
**Signature of Reporting Person Date

 Biotechnology Value Fund II, L.P., By: BVF Partners L.P., its general partner, By: BVF Inc., its general partner, By: /s/ Mark N. Lampert, President   12/19/2018
**Signature of Reporting Person Date

 BVF Partners OS Ltd., By: BVF Partners L.P., its sole member, By: BVF Inc., its general partner, By: /s/ Mark N. Lampert, President   12/19/2018
**Signature of Reporting Person Date

 Biotechnology Value Trading Fund OS LP, By: BVF Partners L.P., its investment manager, BVF Inc., its general partner, By: /s/ Mark N. Lampert, President   12/19/2018
**Signature of Reporting Person Date

 BVF Inc., By: /s/ Mark N. Lampert, President   12/19/2018
**Signature of Reporting Person Date

 /s/ Mark N. Lampert   12/19/2018
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 4(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) This Form 4 is filed jointly by Biotechnology Value Fund, L.P. ("BVF"), Biotechnology Value Fund II, L.P. ("BVF2"), Biotechnology Value Trading Fund OS LP ("Trading Fund OS"), BVF Partners OS Ltd. ("Partners OS"), BVF Partners L.P. ("Partners"), BVF Inc. and Mark N. Lampert (collectively, the "Reporting Persons"). Each of the Reporting Persons is a member of a Section 13(d) group that collectively owns more than 10% of the Issuer's outstanding shares of Common Stock. Each of the Reporting Persons disclaims beneficial ownership of the shares of the Common Stock reported herein except to the extent of his or its pecuniary interest therein.
(2) Securities owned directly by BVF. As the general partner of BVF, Partners may be deemed to beneficially own the securities owned directly by BVF. As the investment adviser and general partner of Partners, BVF Inc. may be deemed to beneficially own the securities owned directly by BVF. As a director and officer of BVF Inc., Mr. Lampert may be deemed to beneficially own the securities owned directly by BVF.
(3) Securities owned directly by BVF2. As the general partner of BVF2, Partners may be deemed to beneficially own the securities owned directly by BVF2. As the investment adviser and general partner of Partners, BVF Inc. may be deemed to beneficially own the securities owned directly by BVF2. As a director and officer of BVF Inc., Mr. Lampert may be deemed to beneficially own the securities owned directly by BVF2.
(4) Securities owned directly by Trading Fund OS. As the general partner of Trading Fund OS, Partners OS may be deemed to beneficially own the securities owned directly by Trading Fund OS. As the investment manager of Trading Fund OS and the sole member of Partners OS, Partners may be deemed to beneficially own the securities owned directly by Trading Fund OS. As the investment adviser and general partner of Partners, BVF Inc. may be deemed to beneficially own the securities owned directly by Trading Fund OS. As a director and officer of BVF Inc., Mr. Lampert may be deemed to beneficially own the securities owned directly by Trading Fund OS.
(5) Securities held in certain Partners managed accounts (the "Partners Managed Accounts"). Partners, as the investment manager of the Partners Managed Accounts, may be deemed to beneficially own the securities held by the Partners Managed Accounts. As the investment adviser and general partner of Partners, BVF Inc. may be deemed to beneficially own the securities held by the Partners Managed Accounts. As a director and officer of BVF Inc., Mr. Lampert may be deemed to beneficially own the securities held by the Partners Managed Accounts.
(6) Series Y Convertible Preferred Stock acquired by BVF and BVF2 following the exercise of each of its basic subscription privilege in connection with the Issuer's subscription rights offering (the "Offering").
(7) Series Y Convertible Preferred Stock acquired by BVF and BVF2 pursuant to the terms and conditions of a backstop commitment made by the Reporting Persons in connection with the Offering.
(8) The Series Y Convertible Preferred Stock may not be exercised if, after such exercise, the Reporting Persons would beneficially own, as determined in accordance with Section 13(d), more than 19.99% of the shares of Common Stock outstanding immediately after giving effect to such exercise. The Series Y Convertible Preferred Stock does not have an expiration date. The initial conversion price is $13.00 and is subject to certain adjustments pursuant to the Certificate of Designation of Preferences, Rights and Limitations of Series Y Convertible Preferred Stock.
(9) The Series X Convertible Preferred Stock may not be exercised if, after such exercise, the Reporting Persons would beneficially own, as determined in accordance with Section 13(d), more than 19.99% of the shares of Common Stock outstanding immediately after giving effect to such exercise. The Series X Convertible Preferred Stock does not have an expiration date. The initial conversion price is $4.03 and is subject to certain adjustments pursuant to the Certificate of Designation of Preferences, Rights and Limitations of Series X Convertible Preferred Stock.

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