SecProbe.io

November 21, 2011
  Via E-mail

Dr. Mark J. Ahn, Ph.D. President  RXi Pharmaceuticals Corporation 60 Prescott Street Worcester, MA 01605

Re: RXi Pharmaceuticals Corporation
Form S-1 Filed October 25, 2011
  File No. 333-177498

Dear Dr. Ahn:

We have reviewed your registration stat ement and have the following comments.
In some of our comments, we may ask you to  provide us with information so we may
better understand your disclosure.
 Please respond to this letter by am ending your registration statement and
providing the requested information.  If you do not believe our comments apply to your
facts and circumstances or do not believe an amendment is appropriate, please tell us why
in your response.

After reviewing any amendment to your registration statement and the
information you provide in response to th ese comments, we may have additional
comments.    FORM S-1

 General

1. We note that you have submitted a numb er of documents in a confidential
treatment request.  Please note that you will be receiving comments to the confidential treatment reque st under separate cover a nd that all c onfidential
treatment issues must be resolved before we will consider a request for acceleration of the re gistration statement.

Dr. Mark J. Ahn
RXi Pharmaceuticals Corporation November 21, 2011 Page 2

2. Please provide updated interim financia l statements and related financial
information for the period ending September 30, 2011, pursuant to Rule 3-01 and 3-12 of Regulation S-X.  Please al so file an updated, signed consent
report from your independent audito rs prior to going effective.

3. Please note that before we will declare the registration statement effective,
you must revise your filing throughout to  include any omitted information that
is currently denoted by blanks.

4. Please note that where we provide exampl es to illustrate what we mean by our
comments, they are examples and not complete lists.  If our comments are applicable to portions of the filings that  we have not cited as examples, please
make the appropriate changes in accordance with our comments.
5. We note that the tax opini on, legal opinion and related consents have not been
filed.  Please file them as soon as pract icable, as we will need time to review
this exhibits once they have been filed.

6. In several places in the registration statement, you cite various estimates,
statistics and other figures.  For example:

a. The statement that “Approximately 42 million surgical procedures are
performed annually…” which is  found on pages 1 and 46; and
b. The statement that “Numerous studies implicate CTGF overexpression in
scarring…” which is found on pages 1 and 46.
In the prospectus, please attribute these statements and other similar
statements to the source from which you obtained the information. In addition,
where you cite your own estimates, pleas e explain how you arrived at those
estimates and disclose any thir d-party sources you relied upon.

7. Throughout the registration statement, you should clearly articulate the basis
of the various beliefs and assertions you make.  As a non-exclusive example,
on pages 1 and 35, you state, “We belie ve that RXI-109 or other CTGF-
targeting compounds may be able to  treat other indications, including
pulmonary fibrosis, liver fibrosis, acut e spinal injury, ocular scarring and
restenosis.” As another example, on pa ge 49, you state, “The specificity of
RNAi may be sufficient to permit th erapeutic targeting…and…may even
selectively reduce or eliminate expre ssion…” If you haven’t done so, please
clarify whether the relevant statement is your belief or opinion.  In addition,
please disclose the basis for your belief.  If any of your assertions of beliefs
are not supported by ample evidence or  knowledge, you should delete them.

Dr. Mark J. Ahn
RXi Pharmaceuticals Corporation November 21, 2011 Page 3
 Cover Page

8. You disclose that following the comp letion of the distri bution, you anticipate
that your common stock will trade in the OTC Markets Group under the symbol [“RXII.”]  Please revise your disclosure he re and on pages 31 and 73
to clarify whether you have filed an app lication for listing.  If an application
has not been filed, please disclo se when you intend to do so.

Table of Contents, page i

9. You state that “We have not independently  verified any of this [data derived
from third-party sources] and cannot  assure you of its accuracy or
completeness.” Please delete this statement as it is not appropriate to disclaim or imply that you are not taking liability for the statements in your registration
statement.   Alternatively, please expand your disclosure to include a
statement specifically accepting lia bility for these statements.

Prospectus Summary, page 1

10. You disclose on page 42 that you have  not generated revenue to date and
may not generate product revenue in the foreseeable future, if ever.
Furthermore, you expect to incur sign ificant operating losses as you advance
your product candidates through the drug development and regulatory
process.  Please expand your disclosure  under “Our Business” to clarify to
disclose this information.

Risk Factors, page 11
11. On page 57, you note that your research  and development activities involve
the controlled use of potentially harm ful biological materials as well as
hazardous materials, chemicals and va rious radioactive compounds.  Please
consider whether you should include a risk  factor that addresses the resulting
risks to you and your business as a result of your use of these materials.

“We may be unable to achieve some or all of  the benefits that we expect…,” page 11
12. You disclose that you may not be able to obtain approval from one or more
granting institutions to Galena’s assi gnment to you of approximately $800,000
of research grants.  Please disclose  whether you are aw are of any granting
institution that has indicate d that it will not consent to the assignment of the
respective grant.

Dr. Mark J. Ahn
RXi Pharmaceuticals Corporation November 21, 2011 Page 4
 “We may be unsuccessful in recruiting a Chief Executive Officer…,” page 11

13. You disclosed that you will need to recr uit and hire a Chief Executive Officer
to replace Mark J. Ahn, Ph.D., who currently serves as our President and Chief Financial Officer, and other ex ecutive officers and key employees.
Please expand your disclosure to list a ll the executive officers you are seeking
to recruit and hire.  For example, are you also seeking to recruit and hire a
Chief Financial Officer?

“We will be subject to competition and ma y not be able to compete...,” page 15

14. Please clarify the diseases you are targe ting which are also being targeted by
your competitors.

“We may be unable to protect  our intellectual property rights licensed from other
parties…,” page 16
15. Please expand your disclosure to disclose the name of the third party that sent
you a letter claiming that you require acce ss to such third party’s patent and
patent applications and demanding th at you stop engaging in unspecified
alleged infringing activities unless you obt ain a license from such third party
as this appears to be information that  may be material to your business.

“Our success depends upon our ability to obtain and maintain intellectual property
protection...,” page 17
16. Please disclose whether there are any other entities which currently have
legally blocking proprietary ri ghts of which you are aware.

“We will rely upon third parties for the manufa cture of our clinical product.” page 17
17. Please disclose whether there are an y third-party manufacturers upon which
you are substantially dependent.   Plea se file the related agreements as
exhibits to your filing and describe the material terms of any such agreements
in your Business section, including, but not limited to any payment provisions,
exclusivity provisions, material obliga tions that must be met to keep the
agreement in place, duration and termination provisions.

“If we fail to attract, hire and re tain qualified personnel...,” page 20
18. To the extent that you have experience d difficulties attracting and retaining
key personnel, please revise to discu ss these difficulties.  Also, disclose
whether any key personnel have plans to  retire or leave your company in the
near future.

Dr. Mark J. Ahn
RXi Pharmaceuticals Corporation November 21, 2011 Page 5
 “You may have difficulty selling our shares of common stock if they are deemed “penny
stocks.”  page 22
19. Please clarify whether you believe that your common stock will be deemed a
“penny stock.”

Plan of Distribution, page 28
 Reasons for the Distribution, page 28

20. Please expand this section to describe in  more detail the negative factors and
potential benefits the Galena board cons idered in evaluati ng the separation of
RXi from Galena.
21. Please clarify whether you are responsible for the entire cost of the fees and
expenses disclosed on the top of page 29, as we note that you have agreements
related to the reimburseme nt of transaction costs as described on page 30.

Trading Market, page 31
22. You state on page 32, “These are just so me of the factors that may adversely
affect the market price of our common stock.”  Please confirm that you have
described all material fact ors likely to adversely impact the market price of
your common stock or revise the disclo sure to include additional material
factors.

Trading Between the Record Date  and Distribution Date, page 32
23. Please confirm that your record date w ill be after the eff ectiveness of this
registration statement.  Alternativel y, please provide us with a detailed
analysis which supports your conclusion that the “when-issued” trading is
consistent with Section 5 of the Securities Act of 1933.

Management’s Discussion and Analysis of Fi nancial Condition and Results of Operations
 Liquidity and Capital Resources, page 42

24. You disclose that you had cash and cas h equivalents of approximately $1.9
million as of October 15, 2011.  Please cl arify whether this includes the $1.5
million contribution by Galena wh ich you disclosed on page 30.

Dr. Mark J. Ahn
RXi Pharmaceuticals Corporation November 21, 2011 Page 6
 Business, page 46

25. Please clarify which human diseases or  types of human diseases you believe
can be potentially treated by silencing ta rgeted genes that lead to disease
together with your basis for such belief.

Recent Business Developments, page 47
26. In each discussion of the initial results of your preclinical research and data
please clarify if there was a specific duration in which the silencing was
experienced.  In this regard, we notice your reference to one week on page 1.
27. In the third bullet point you note that th e collaboration demonstrated efficacy.
Please revise your disclosure to cl arify what you mean by “demonstrated
efficacy” as it does not appear to be appr opriate to use this term in reference
to a pre-clinical  collaboration.

Introduction to the Field of RNAi Therapeutics, page 48
28. Please characterize as your belief or opinion the statement that “The
specificity of RNAi may be sufficient to permit therapeutic targeting…and…may even selectively reduce or eliminate expression…”
Alternatively, provide additional fact ual support for this assertion.

Patents and Patent Applications, page 54

29. In this section, you refere nce both patents and patent applications, but you
appear to only discuss your material patent applications.  Please expand your
disclosure in this section to also di scuss any material patents, including for
each patent or group of patents the tec hnology to which the patent relates and
the expiration date of the patent.
30. Please clarify if you have any patents or patent applications  in jurisdictions
outside the United States.

License Agreements, page 54
31. Please disclose the aggregate milest one payments you are required to pay
under the license agreement with the University of Massachusetts Medical
School.

Dr. Mark J. Ahn
RXi Pharmaceuticals Corporation November 21, 2011 Page 7
 32. Please disclose the aggregate clinical milestone payments and a range of
royalty payments (not to exceed ten per cent) under the license agreement with
Dharmacon, Inc.
33. For each of the license agreements below,  please provide us with an analysis
that supports your conclusion that you ar e not substantially dependent on the
following agreements disclosed on page F-28:
 License agreement with Cold  Spring Harbor Laboratory;
 License agreement with TriLink Biotechnologies;
 License agreement with Life Technologies; and
 License agreements with University  of Massachusetts Medical School,
other than the license  agreement already disclosed on page 54.

Alternatively, please file th e license agreements as exhibits to your filing and
describe the material terms of any su ch agreements in your Business section,
including, but not limited to any pa yment provisions, aggregate milestone
payments, a range of royalty payments , exclusivity provisions, material
obligations that must be met to keep  the agreement in place, duration and
termination provisions.
 Management, page 59

34. We note that Mark Ahn also serves as the President, Chief Executive Officer
and a director of Galena.  Please expa nd your disclosure here and on page 66
to disclose the number of hours Mr. Ahn has agreed to dedicate to you.  Please
also consider adding a risk factor to discuss the risks that  your President and
Chief Financial Officer is not working full time for you, is not being compensated by you and may have conflicts of interests with you.

Certain Relationships and Relate d Party Transactions, page 65

 Agreements with Galena Biopharma, Inc., page 65

35. Here, and in the Business section as a ppropriate, please disclose the names of
the institutions which granted the resear ch grants and the license agreements
that Galena has assigned to you in  connection with the contribution
agreement.

Advirna Agreement, page 66
36. Please disclose the exact nature of the affiliation between Advirna and
Anastasia Khvorova.

Dr. Mark J. Ahn
RXi Pharmaceuticals Corporation November 21, 2011 Page 8
 Beneficial Ownership of Certain Bene ficial Owners and Management, page 68

37. Although we note that there is a “conve rsion cap” limitation for certain of
your investors, the security holders’ abili ty to acquire and sell a large amount
of your common stock is material in formation which is required to be
disclosed in your registration statem ent. See Securities Act Rule 408.
Accordingly, please revise your tabl e to include the ownership of Tang
Capital Partners, RTW Investments,  Mr. Tang and Mr. Wong without
consideration of the “conve rsion limitation.”  In a ddition, please include a
footnote to your beneficial ownershi p table that discloses the “conversion
limitation” and the impact on the respective security holders.

Exhibits
38. We note that Exhibits 2.1 and 2.2 each omit various schedules and exhibits
thereto.   Please either file complete c opies of these agreements or provide us
with a detailed analysis of each omitte d schedule, exhibit or other attachment
thereto that supports your belief th at such schedule does not contain
information which is material to an in vestment decision or which is otherwise
disclosed in the agreement or the filing and provide us copies of each omitted
schedule, exhibit or other attachment th ereto. In addition, please re-file each
agreement with a list briefly identifying the contents of all omitted schedules, together with an agreement to furnish supplementally a copy of any omitted
schedule to the Commission upon request.  See Item 601(b)(2) of Regulation
S-K.

We urge all persons who are responsible for the accuracy and adequacy of the
disclosure in the filing to be certain that the filing includes the information the Securities
Act of 1933 and all applicable Securities Act rules require.  Sinc