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)
__X__ Director __X__ 10% Owner
_____ Officer (give title below) __X__ Other (specify below)
See Remarks
(Last)
(First)
(Middle)
44 MONTGOMERY STREET, 40TH FLOOR
3. Date of Earliest Transaction (Month/Day/Year)
09/21/2020
(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) 09/21/2020   P   12,259 A $ 18.3851 2,023,276 D (2)  
Common Stock, $0.0075 par value per share (1) 09/22/2020   P   6,960 A $ 18.4457 2,030,236 D (2)  
Common Stock, $0.0075 par value per share (1) 09/23/2020   P   9,888 A $ 18.1998 2,040,124 D (2)  
Common Stock, $0.0075 par value per share (1) 09/21/2020   P   10,069 A $ 18.3851 1,738,512 D (3)  
Common Stock, $0.0075 par value per share (1) 09/22/2020   P   4,991 A $ 18.4457 1,743,503 D (3)  
Common Stock, $0.0075 par value per share (1) 09/23/2020   P   7,201 A $ 18.1998 1,750,704 D (3)  
Common Stock, $0.0075 par value per share (1)               159,537 D (4)  
Common Stock, $0.0075 par value per share (1)               231,878 I (5) See footnote (5)
Common Stock, $0.0075 par value per share (1)               11,799 I (7) See footnote (7)

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
Series X Convertible Preferred Stock (6)               (6)   (6) Common Stock, $0.0075 par value per share 2,313,000   2,313 D (2)  
Series X Convertible Preferred Stock (6)               (6)   (6) Common Stock, $0.0075 par value per share 1,506,000   1,506 D (3)  
Series X Convertible Preferred Stock (6)               (6)   (6) Common Stock, $0.0075 par value per share 412,000   412 D (4)  
Series X Convertible Preferred Stock (6)               (6)   (6) Common Stock, $0.0075 par value per share 772,000   772 I (5) See footnote (5)
Non-Qualified Stock Option (right to buy) $ 21.27               (8) 05/20/2030 Common Stock, $0.0075 par value per share 6,152   6,152 I (7) See footnote (7)
Non-Qualified Stock Option (right to buy) $ 15.59               (9) 05/16/2029 Common Stock, $0.0075 par value per share 8,167   8,167 I (7) See footnote (7)
Non-Qualified Stock Option (right to buy) $ 25.16               (10) 05/17/2028 Common Stock, $0.0075 par value per share 5,052   5,052 I (7) See footnote (7)
Non-Qualified Stock Option (right to buy) $ 4.67               (11) 03/02/2027 Common Stock, $0.0075 par value per share 15,222   15,222 I (7) See footnote (7)

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   X   See Remarks
BIOTECHNOLOGY VALUE FUND L P
44 MONTGOMERY STREET
40TH FLOOR
SAN FRANCISCO, CA 94104
    X    
BVF I GP LLC
44 MONTGOMERY ST., 40TH FLOOR
SAN FRANCISCO, CA 94104
    X    
BIOTECHNOLOGY VALUE FUND II LP
44 MONTGOMERY STREET
40TH FLOOR
SAN FRANCISCO, CA 94104
    X    
BVF II GP LLC
44 MONTGOMERY ST., 40TH FLOOR
SAN FRANCISCO, CA 94104
    X    
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 GP HOLDINGS LLC
44 MONTGOMERY ST., 40TH FLOOR
SAN FRANCISCO, CA 94104
    X    
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   09/23/2020
**Signature of Reporting Person Date

 Biotechnology Value Fund, L.P., By: BVF Partners L.P., its investment manager, By: BVF Inc., its general partner, By: /s/ Mark N. Lampert, President   09/23/2020
**Signature of Reporting Person Date

 BVF I GP LLC, By: /s/ Mark N. Lampert, Chief Executive Officer   09/23/2020
**Signature of Reporting Person Date

 Biotechnology Value Fund II, L.P., By: BVF Partners L.P., its investment manager, By: BVF Inc., its general partner, By: /s/ Mark N. Lampert, President   09/23/2020
**Signature of Reporting Person Date

 BVF II GP LLC, By: /s/ Mark N. Lampert, Chief Executive Officer   09/23/2020
**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   09/23/2020
**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   09/23/2020
**Signature of Reporting Person Date

 BVF GP Holdings LLC, By: /s/ Mark N. Lampert, Chief Executive Officer   09/23/2020
**Signature of Reporting Person Date

 BVF Inc., By: /s/ Mark N. Lampert, President   09/23/2020
**Signature of Reporting Person Date

 /s/ Mark N. Lampert   09/23/2020
**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 I GP LLC ("BVF GP"), BVF II GP LLC ("BVF2 GP"), BVF GP Holdings LLC ("BVF GPH"), 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 securities 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, BVF GP may be deemed to beneficially own the securities owned directly by BVF. As the sole member of BVF GP, BVF GPH may be deemed to beneficially own securities owned directly by BVF. As the investment manager 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, BVF2 GP may be deemed to beneficially own the securities owned directly by BVF2. As the sole member of BVF2 GP, BVF GPH may be deemed to beneficially own securities owned directly by BVF2. As the investment manager 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) 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.
(7) Partners, BVF Inc. and Mr. Lampert may be deemed to have a pecuniary interest in the securities reported owned herein due to a certain agreement between Partners and Matthew D. Perry, who serves on the Issuer's board of directors and as President of Partners, pursuant to which Mr. Perry is obligated to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the securities reported owned herein to Partners. As such, Mr. Perry disclaims beneficial ownership of the securities reported herein except to the extent of his pecuniary interest therein.
(8) The shares subject to this option shall vest and become exercisable in equal monthly installments over the 12-month period following the date of grant (May 20, 2020), provided that the final installment will occur on the earlier of (i) the date of the next annual meeting of the Company's stockholders or (ii) the first anniversary of the date of grant of such option.
(9) All of the shares subject to this option vested and became exercisable in twelve equal monthly installments. As of May 16, 2020, these options are fully exercisable.
(10) These options were acquired pursuant to a grant of stock options under the Amended and Restated XOMA Corporation 2010 Long Term Incentive and Stock Award Plan (the "Plan") and were scheduled to vest and become exercisable on the one-year anniversary of the grant date of May 17, 2018. As of May 17, 2019, these options are fully exercisable.
(11) These options were acquired pursuant to the Plan, and were exercisable in twelve equal monthly installments, beginning one month from the vesting commencement date, which was February 15, 2017. As of February 15, 2018, these options are fully exercisable.
 
Remarks:
For purposes of Section 16 of the Securities Exchange Act of 1934, as amended, Partners may be deemed to be a director by deputization of the Issuer due to the President of Partners, Matthew D. Perry, serving on the Issuer's board of directors, and his agreement to transfer the economic benefit, if any, received upon the sale of the shares issuable upon exercise of the securities reported owned herein to Partners.

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