Exhibit 10.33

TERMINATION AGREEMENT

This Termination Agreement (the "Agreement") is made as of this 30th day of January 2008 (the "Termination Date") by and between Daiichi
Sankyo Company, Ltd. ("Daiichi Sankyo"), a Japanese corporation having its principal place of business at 5-1 Nihonbashi-Honcho, 3-chome, Chuo-ku, Tokyo
103-8426, Japan, and Metabasis Therapeutics, Inc. ("Metabasis"), a Delaware corporation having its principal place of business at 11119 North Torrey Pines Road, La Jolla, California
92037. Capitalized terms used herein but not otherwise defined in this Agreement shall have the meanings set forth in the Amended and Restated Collaborative Research and Development and License
Agreement between Sankyo Co., Ltd. (which was merged with Daiichi Sankyo as of April 1, 2007) and Metabasis, dated June 30, 1999 (the "License Agreement").

WITNESSETH:

WHEREAS, Daiichi Sankyo and Metabasis entered into the License Agreement pursuant to which the parties conducted a research program and Daiichi Sankyo commenced
clinical development on the Licensed Compound known as CS-917 and also entered into the Exclusive Option Agreement, dated as of October 21, 2002 (the "Option Agreement") pursuant to
which the parties conducted additional activities in the Field, which Option Agreement has expired; and

WHEREAS,
Daiichi Sankyo and Metabasis have mutually agreed to terminate the License Agreement;

NOW,
THEREFORE, in consideration of the premises and the mutual agreements, covenants, and conditions set forth in this Agreement and other good and valuable consideration, the receipt
and sufficiency of which are hereby acknowledged, Daiichi Sankyo and Metabasis, intending to be legally bound, hereby agree as follows:

1.Termination of License Agreement.

(a)   Daiichi
Sankyo and Metabasis each agrees that the License Agreement shall be terminated as of the Termination Date. Notwithstanding anything to the
contrary in the License Agreement, effective upon the Termination Date, all rights and obligations of the parties under the License Agreement shall terminate except as expressly set forth in this
Termination Agreement. All rights to all compounds discovered or generated in the course of research and development activities conducted by the parties under the License Agreement and/or the Option
Agreement, including, without limitation, all Compounds, shall revert to (i) Metabasis if such compounds were discovered or generated by Metabasis or were licensed to Metabasis from a Third
Party and (ii) Daiichi Sankyo if such compounds were discovered or generated by Daiichi Sankyo.

(b)   MTI
Inventions shall continue to be owned by Metabasis and Sankyo Inventions shall continue to be owned by Daiichi Sankyo, except as provided in
Section 2(c).

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(c)   Notwithstanding
the termination of the License Agreement, Daiichi Sankyo and Metabasis, as applicable, shall undertake the obligations as set forth in
Section 1(a) above and Sections 2 and 3 below.

2.Outstanding Obligations with Respect to Daiichi Sankyo.    Daiichi Sankyo and Metabasis each agrees and acknowledges that, as
soon as practicable after the Termination Date, with respect to Daiichi Sankyo:

(a)   Daiichi
Sankyo shall keep open and active the Investigational New Drug Application filed with the Food and Drug Administration ("FDA") for the Licensed
Compound, as well as any comparable application(s) filed with any regulatory body in any other jurisdiction for the Licensed Compound (the "Regulatory Filings") while the following actions described
in this Section 2(a) are taken. Daiichi Sankyo shall, promptly after its finalization, deliver to Metabasis (i) the final study report for the clinical study
(CS-917-A-U205), and (ii) the final study reports for the clinical pharmacology studies (U-111 Cimet/Quin; U-113
BA-abbreviated CTR; and U112 14C/ADME). Daiichi Sankyo confirms that there are no final study reports with respect to the Licensed Compound to be written other than those referenced in the
preceding sentence. Metabasis shall, within 90 days after receipt of all such final study reports, notify Daiichi Sankyo in writing whether Metabasis elects to have Daiichi Sankyo transfer the
Regulatory Filings to Metabasis or to have Daiichi Sankyo close the Regulatory Filings. Effective upon written notice by Metabasis to Daiichi Sankyo that Metabasis elects to have Daiichi Sankyo
transfer the Regulatory Filings to Metabasis, Daiichi Sankyo shall, and hereby does effective upon such written notice, transfer and assign the Regulatory Filings to Metabasis so that Metabasis may
conduct development activities with the Licensed Compound pursuant to such Regulatory Filings. Daiichi Sankyo shall also promptly transfer to Metabasis all documentation with respect to the Regulatory
Filings and shall make such filings with the FDA and any other applicable regulatory body as necessary or appropriate to effect such transfer and assignment to Metabasis. Daiichi Sankyo will bear any
costs with respect to such transfer and assignment to Metabasis and related filings. If Metabasis elects to have Daiichi Sankyo close the Regulatory Filings or does not notify Daiichi Sankyo in
writing within such time frame, then Daiichi Sankyo shall promptly take all necessary actions to close the Regulatory Filings.

(b)   Daiichi
Sankyo shall, and hereby does, transfer and assign all data in the Regulatory Filings and all information and data from any clinical or preclinical
studies of the Licensed Compound conducted by or on behalf of Daiichi Sankyo, including statistical models, integrated and individual data sets, final reports and all regulatory correspondence, to
Metabasis, which information and data Metabasis may use for research, development and commercialization of the Licensed Compound and any product containing the Licensed Compound by or on behalf of
Metabasis, including through any affiliate, licensee or assignee. Daiichi Sankyo shall also promptly transfer to Metabasis, at Daiichi Sankyo's expense, all documentation with respect to such
information and data. Daiichi Sankyo shall provide such data and Regulatory Filings to Metabasis in electronic format.

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(c)   Daiichi
Sankyo shall, and hereby does, assign its interest in (i) patent application No. MTI037 and (ii) the Sankyo Invention patent
applications numbered FP0529, and FP0626 (collectively, the "Patent Applications", as more fully described in Exhibit A-1 attached hereto) to Metabasis, and Metabasis shall
thereafter bear all responsibility, expenses and costs relating to such Patent Applications; provided, however, and subject to, Metabasis granting to Daiichi Sankyo a non-exclusive, fully
paid-up, perpetual, irrevocable, worldwide license, including the right to grant sublicenses, to the Patent Applications. Daiichi Sankyo shall promptly transfer to Metabasis all
documentation with respect to the Patent Applications, including, without limitation, all correspondence with any patent office, and shall make such filings with each applicable patent office as
necessary or appropriate to effect the assignment of the Patent Applications to Metabasis. Daiichi Sankyo will bear any costs with respect to such transfer and assignment to Metabasis of the Patent
Applications and related filings. Daiichi Sankyo confirms to Metabasis that Daiichi Sankyo does not own or control any patent, patent application or invention with respect to compounds discovered,
generated or developed in the course of research and development activities conducted by the parties under the License Agreement or the Option Agreement other than the Patent Applications. Daiichi
Sankyo shall abandon the Daiichi Sankyo Invention patent applications numbered FP0318, FP0530, FP0706, FP0603 and JP2006-251995 (collectively, the "Abandoned Applications", as more fully
described in Exhibit A-2 attached hereto) and shall not, whether directly or indirectly, revive or seek to revive all or any part of the Abandoned Applications.

(d)   Daiichi
Sankyo confirms to Metabasis that Daiichi Sankyo has ceased, in accordance with the agreement between Metabasis and Daiichi Sankyo, all activities
related to the toxicology, chemistry manufacturing and controls, and pharmacokinetic studies and activities relating to the Licensed Compound set forth in Exhibit B attached hereto, and shall
not use any materials, data or information from such activities, provided that Daiichi Sankyo shall, at Daiichi Sankyo's cost, transfer 3 kg from the inventory of API described in Exhibit B to
Metabasis.

(e)   Daiichi
Sankyo shall remain responsible for all liability, obligations, costs and expenses related to all studies and activities relating to the Licensed
Compound conducted by or on behalf of Daiichi Sankyo, including, without limitation, those studies and activities set forth in Exhibit B, and shall indemnify and hold harmless Metabasis and its
directors and employees with respect to any claims or losses arising from or relating to any such studies and activities, except to the extent that any claims or losses are based solely upon studies
and activities for which Metabasis has an indemnification obligation under Section 3(b).

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(f)    Daiichi
Sankyo shall destroy all FBPase constructs and related expression vectors and protocols for screening and shall confirm in writing to Metabasis
that all of such items have been destroyed.

(g)   Daiichi
Sankyo shall, at Daiichi Sankyo's expense, store blood samples obtained in connection with studies of the Licensed Compound and shall not use such
blood samples unless subsequently agreed in writing by Daiichi Sankyo and Metabasis for potential future pharmacogenomic studies. Should Daiichi Sankyo and Metabasis not agree on the pharmacogenomic
studies, Daiichi Sankyo may destroy such blood samples.

(h)   Daiichi
Sankyo may publish information from non-clinical studies of the Licensed Compound as summarized on Exhibit C subject to compliance with the
conditions of this Section 2(h). Before any such material is submitted for publication, Daiichi Sankyo shall first deliver a complete copy of the proposed publication to Metabasis at least
30 days prior to submitting the material to a publisher and obtain Metabasis' written consent to proceed with such publication, provided that Metabasis shall notify Daiichi Sankyo of any
comments it may have within 20 days from the date which it receives such proposed publication from Daiichi Sankyo and shall not unreasonably withhold such consent.

3.Outstanding Obligations with Respect to Metabasis.

(a)   Daiichi
Sankyo and Metabasis each agrees and acknowledges that, as soon as practicable after the Effective Date, with respect to Metabasis, Metabasis shall
(i) accept assignment and assume full title and ownership of the Patent Applications and (ii) grant to Daiichi Sankyo a non-exclusive, fully paid-up, perpetual,
irrevocable, worldwide license, including the right to grant sublicenses, to the Patent Applications.

(b)   Metabasis
shall indemnify and hold harmless Daiichi Sankyo and its directors and employees with respect to any claims or losses arising from or relating to
any future studies or activities conducted by Metabasis in connection with, or relating to, the Licensed Compound, except to the extent that any claims or losses are based solely upon studies and
activities for which Daiichi Sankyo has an indemnification obligation under Section 2(e).

4.Indemnification Procedure.    A party entitled to indemnification pursuant to Sections 2(e) or 3 (b) shall
notify the indemnifying party promptly of any claim that might give rise to a claim of indemnification, shall allow the indemnifying party to handle the defense of the claim (provided the indemnifying
party acknowledges its obligation to indemnify hereunder), shall cooperate in the defense of such claim, and shall not settle such claim without the indemnifying party's written consent (which shall
not be unreasonably withheld, delayed or conditioned). An indemnified party shall have the right to participate in the defense of any matter as to which indemnification is being provided with its own
counsel and at its own expense.

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5.Release.    In consideration of the foregoing agreements, acknowledgments and obligations, except as expressly set forth in
this Agreement, Daiichi Sankyo and Metabasis each agree that the other shall no longer bear any liability, duty, or obligation whatsoever arising under or related to the License Agreement or any
matters relating to the relationship between the parties with respect to research and development of compounds and products, including Compounds, for treatment of diabetes, and shall be immediately
released from any and all such liabilities, duties or obligations arising prior to, and existing at, the time of this Agreement. Each party acknowledges that it has read and understood
Section 1542 of the Civil Code of the State of California (set forth below) and hereby expressly waives and relinquishes all rights and benefits under Section 1542 and any law or legal
principle of similar effect in any jurisdiction with respect to the release set forth in this Section 5:



6.Survival.    The provisions of Article 11 (Confidentiality) shall survive termination of the License Agreement;
provided that the parties acknowledge and agree that all Information transferred or assigned to Metabasis pursuant to this Agreement shall be Information of Metabasis.

7.Notices.    All notices required or permitted under this Agreement shall be in writing and shall be deemed to have been duly
given when: (i) delivered by hand, courier, or express mail service (with written confirmation of receipt); (ii) sent by means of facsimile or other wire transmission (with provision for
assurance of receipt in a manner typical with respect to communications of that type); or (iii) mailed by registered or certified first class mail, return receipt requested, to the address or
facsimile (fax) number set forth below (or to such other person, address, or facsimile (fax) number as a party may, from time to time, designate by written notice):





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8.Publicity.    A party shall not, except with the prior written consent of the other party, issue, or cause to be issued, any
press release, or other public statement on or in any way related to this Agreement or the License Agreement or the rights and obligations thereunder; provided, however, that either party may
(i) issue statements as required by applicable law and (ii) disclose information or issue public statements already approved by a party pursuant to the License Agreement, or with the
prior consent of the other party.

9.Governing Law.    This Agreement, including, without limitation, its construction, interpretation, breach, and damages for
breach, shall be governed by and construed in accordance with the laws of the State of California (without regard to its conflict of laws principles).

10.Waiver.    A party's failure to exercise or enforce any right conferred upon it hereunder shall not be deemed a waiver of any
such right or any other right or operate to bar the exercise or enforcement thereof at any time or times thereafter; nor shall a party's waiver of any right hereunder at any time be deemed a waiver
thereof for any other time.

11.Severability.    If any provision of this Agreement should be finally determined by a court of competent jurisdiction to be
invalid, illegal or unenforceable for any reason, the parties shall negotiate in good faith a valid, legal and enforceable substitute provision that most nearly reflects the original intent of the
parties and all other provisions hereof shall remain in full force and effect in such jurisdiction and shall be liberally construed in order to carry out the intentions of the parties as nearly as may
be possible. Such invalidity, illegality or unenforceability shall not affect the validity, legality or enforceability of such provision in any other jurisdiction.

12.Further Assurances.    Each of the parties shall perform such acts, execute and deliver such instruments and documents, and
do all such other things as may be reasonably necessary to accomplish the purpose and transfer the intellectual property rights, filings, data and activities contemplated under this Agreement.

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13.Counterparts, Headings and Ambiguities.    The division of this Agreement into sections and the insertion of headings are for
convenience of reference only and shall not affect the construction or interpretation of this Agreement. This Agreement may be executed in any number of counterparts, each of which shall be deemed an
original but all of which taken together shall constitute one and the same instrument. In interpreting any provision of this Agreement, no weight shall be given to, nor shall any construction or
interpretation be influenced by, the fact that counsel for one of the parties drafted this Agreement, each party recognizing that it and its counsel have had an opportunity to review this Agreement
and have contributed to the final form of the same.

14.Entire Agreement.    This Agreement represents and contains the full and complete understanding and agreement of the parties
with respect to the subject matter hereof and supersedes all prior and contemporaneous agreements, understandings, statements, clauses, and conditions with respect to the transactions contemplated by
this Agreement or which may be contained in any other form or document.

IN
WITNESS WHEREOF, the parties have executed this Agreement as of the date first above written.

|DAIICHI SANKYO COMPANY, LTD.                      |  | METABASIS THERAPEUTICS, INC.       
|------------------------------------------------- |  | -----------------------------------
|By:    /s/ Kazunori Hirokawa                      |  | By:    /s/ Ed Baracchini           
|Name:    Kazunori Hirokawa                        |  | Name:    Ed Baracchini             
|Title:    Executive Officer, Head of R&D Division |  | Title:    SVP, Business Development
|Date:    Jan 30, 2008                             |  | Date:    Jan. 31, 2008             

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EXHIBIT A-1PATENT APPLICATIONS

MT1037

Title:    Combination of FBPase Inhibitor and anti diabetic agents

<Combination use> FBPase inhibitors + Anti-diabetics (Insulin, SU etc.)

|country |  | application No.   |  | filing date |  | 
|------- |  | ----------------- |  | ----------- |  | 
|AU      |  | 2001273271        |  | 7/5/2001    |  | 
|BR      |  | P10112212-6       |  | 7/5/2001    |  | 
|CA      |  | 2412142           |  | 7/5/2001    |  | 
|CN      |  | 1814924.3         |  | 7/5/2001    |  | 
|CZ      |  | PV2003-5          |  | 7/5/2001    |  | 
|EP      |  | 1952530.2         |  | 7/5/2001    |  | 
|HK      |  |                   |  |             |  | 
|HU      |  | US01/21557        |  | 7/5/2001    |  | 
|ID      |  | 2002000977        |  | 7/5/2001    |  | 
|IL      |  | 153513            |  | 7/5/2001    |  | 
|IN      |  | PCT/200201873     |  | 7/5/2001    |  | 
|JP      |  | 2002-508433       |  | 7/5/2001    |  | 
|KR      |  | 2003-7000126      |  | 7/5/2001    |  | 
|MX      |  | PA/a/2002/012713  |  | 7/5/2001    |  | 
|NO      |  | 2003-0034         |  | 7/5/2001    |  | 
|NZ      |  | 523227            |  | 7/5/2001    |  | 
|PL      |  | 365779            |  | 7/5/2001    |  | 
|RU      |  | 2003 7000126      |  | 7/5/2001    |  | 
|SG      |  | 200207558-8       |  | 7/5/2001    |  | 
|SK      |  | PP6-2003          |  | 7/5/2001    |  | 
|US      |  | 09/900364         |  | 7/5/2001    |  | 
|VN      |  | 1-2003-00101      |  | 7/5/2001    |  | 
|WO      |  | PCT/US2001/021557 |  | 7/5/2001    |  | 
|ZA      |  | 2003/0044         |  | 7/5/2001    |  | 

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FP0529

Title:    Medicinal composition for treating diabetes

<Combination use> FBPase inhibitors + Biguanides

|country |  | application No.   |  | filing date |  | 
|------- |  | ----------------- |  | ----------- |  | 
|BR      |  | PI0519006-1       |  | 12/12/2005  |  | 
|CA      |  | 2590883           |  | 12/12/2005  |  | 
|CN      |  |                   |  | 12/12/2005  |  | 
|EP      |  | 5814764.6         |  | 12/12/2005  |  | 
|JP      |  | 2005-357073       |  | 12/12/2005  |  | 
|KR      |  | 2007-7013097      |  | 12/12/2005  |  | 
|TW      |  | 94143827          |  | 12/12/2005  |  | 
|US      |  | 11/792879         |  | 12/12/2005  |  | 
|WO      |  | PCT/US2005/022739 |  | 12/12/2005  |  | 

FP0626

Title:    Drug containing FBPase Inhibitor

<Combination use> CS-917 + MK0431 (DPP-IV inhibitor)

|country |  | application No.   |  | filing date |  | 
|------- |  | ----------------- |  | ----------- |  | 
|TW      |  | 95130334          |  | 8/18/2006   |  | 
|WO      |  | PCT/JP2006/316292 |  | 8/21/2006   |  | 

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EXHIBIT A-2ABANDONED APPLICAT1ONS

FP0318

Title:    Preventive agents for diabetes mellitus

<Use>
treatment for IGT

|country |  | application No. |  | filing date |  | 
|------- |  | --------------- |  | ----------- |  | 
|EP      |  | 3765368         |  | 7/23/2003   |  | 
|JP      |  | 2003-200333     |  | 7/23/2003   |  | 
|US      |  | 10/522401       |  | 7/23/2003   |  | 
|WO      |  | PCT/JP03/09348  |  | 7/23/2003   |  | 

FP0530

Title:    Medicinal composition containing FBPase Inhibitor

<Combination
use> FBPase inhibitors + CS-011

|country |  | application No.   |  | filing date |  | 
|------- |  | ----------------- |  | ----------- |  | 
|BR      |  | PI0519015-0       |  | 12/14/2005  |  | 
|CA      |  | 2591416           |  | 12/14/2005  |  | 
|CN      |  |                   |  | 12/14/2005  |  | 
|EP      |  | 5816808.9         |  | 12/14/2005  |  | 
|JP      |  | 2005-359751       |  | 12/14/2005  |  | 
|KR      |  | 2007-7013335      |  | 12/14/2005  |  | 
|TW      |  | 94144174          |  | 12/14/2005  |  | 
|US      |  | 11/818534         |  | 12/14/2005  |  | 
|WO      |  | PCT/US2005/022915 |  | 12/14/2005  |  | 

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FP0706

Title:    Preparation produced by dry process

<Formulation>
process for preparing CS-917 tablet

|country |  | application No.   |  | filing date |  | 
|------- |  | ----------------- |  | ----------- |  | 
|TW      |  | 96112406          |  | 4/10/2007   |  | 
|WO      |  | PCT/JP2007/057832 |  | 4/9/2007    |  | 

Back-ups

FP0603

Title:    Thiazole compound

|country |  | application No.   |  | filing date |  | 
|------- |  | ----------------- |  | ----------- |  | 
|JP      |  | 2006-82453        |  | 3/24/2006   |  | 
|WO      |  | PCT/JP2006/305940 |  | 3/24/2006   |  | 

JP2006-251995

Title:    Pharmaceutical composition containing thiazole compound

|country |  | application No. |  | filing date |  | 
|------- |  | --------------- |  | ----------- |  | 
|JP      |  | 2006-251995     |  | 9/19/2006   |  | 

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EXHIBIT BONGOING STUDIES AND ACTIVITIES RELATED TO THE LICENSED COMPOUND

TOX

|Mouse CA study |  | -Start of administration: May 24, 2006  |  | -Facility BOZO research (CRO, Japan) 
|-------------- |  | --------------------------------------- |  | -------------------------------------
|Rat CA study   |  | -Start of Administration: June 13, 2006 |  | -Facility: BOZO research (CRO, Japan)
|               |  |                                         |  |                                      

CMC

|Inventory of API (final method) in GMP condition |  | About 300kg                                                            |  | To be retested                                             
|------------------------------------------------ |  | ---------------------------------------------------------------------- |  | -----------------------------------------------------------
|Inventory of clinical supply in GMP condition    |  | 25mg 550K tabs, 50 mg 550K tabs, 100mg 500K tabs and placebo 1.2M tabs |  | Use by date
-Placebo: Sep 2011
-25mg, 50mg, 100mg: Oct 2010
|Stability studies (API, DP)                      |  | DP: Planned for 3 years (Oct 2006-Oct 2009)                            |  |                                                            
|DMF                                              |  | Annual report was submitted in July 2007                               |  |                                                            
|                                                 |  |                                                                        |  |                                                            

PK

|Measurement of PK sample in the 205 study |  | Preliminary measure was completed |  | -Facility: Simbec, UK
|----------------------------------------- |  | --------------------------------- |  | ---------------------

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EXHIBIT CPUBLICATION PLAN RELATED TO NON-CLINICAL STUDIES OF CS-917 AND BACKUP COMPOUNDS

TOX

|Area                                    |  | Title (tentative)                                                                                                                           |  | Timing for submission
|--------------------------------------- |  | ------------------------------------------------------------------------------------------------------------------------------------------- |  | ---------------------
|Pharmacology                            |  | CS-917 inhibits hepatic GNG In vivo and improves post prandial hyperglycaemia in GK rats                                                    |  | 1Q 2008              
|Pharmacology                            |  | CS-917 decreases PG and acts on liver as prodrug in cynomolgus monkeys                                                                      |  | 1Q 2008              
|Pharmacology                            |  | CS-917 decreases hepatic glucose production, whereas metformin increases intestinal lactate production                                      |  | 1Q 2008              
|Pharmacology                            |  | Different effects of CS-917 and metformin in vivo and possibility of combination treatment                                                  |  | 2Q 2008              
|Pharmacology                            |  | Enhancement of Insulin action improves lactate metabolism in combination with CS-917                                                        |  | 3Q 2008              
|ADME                                    |  | Preclinical Pharmacokinetics and ADME of CS-917                                                                                             |  | by the end of 2009   
|ADME                                    |  | Identification of renal transporters in human                                                                                               |  | by the end of 2009   
|ADME                                    |  | Identification of activating enzymes in human                                                                                               |  | by the end of 2009   
|ADAM                                    |  | Species differences, including human, in hepatic uptake                                                                                     |  | by the end of 2009   
|ADME                                    |  | Species differences, including human, in renal excretion                                                                                    |  | by the end of 2009   
|ADME                                    |  | Human Metabolism                                                                                                                            |  | by the end of 2009   
|Analysis                                |  | Elucidation of the chemical structure of volatile degradation product and their degradation mechanism for active pharmaceutical ingredients |  | 4Q 2008              
|Process research                        |  | Development of manufacturing process for CS-917                                                                                             |  | by the end of 2009   
|Back up compounds (Medicinal chemistry) |  | Novel tricyclic derivatives as potent FBPase inhibitors (several articles*)                                                                 |  | by the end of 2009   
|                                        |  |                                                                                                                                             |  |                      

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All
articles are subject to review by Metabasis before submission.

Daiichi
Sankyo will not newly initiate studies related to those listed in this table.

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