SecProbe.io

Mail Stop 4720
March 4, 2016

Walter Klemp
Chief Executive Officer
Moleculin Biotech, Inc.
2575 West Bellfort, Suite 333
Houston, Texas 77054

Re: Moleculin Biotech , Inc.
Registration Statement on Form S -1
Filed February 1, 2016
  Amendment No. 1 to Registration Statement on Form S -1
Filed February 16, 2016
File No. 333-209323

Dear Mr. Klemp :

We have reviewed your registration statement  and amendment 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 amending 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 you r
response.

After reviewing any amendment to your registration statement and the information you
provide in response to these  comments, we may have additional comments.

Registration Statement on Form S -1

Company Information and Moleculin  Merger, page 5

1. Please tell us how you will account for the operating loans to Mol eculin in the amount of
$300,000 to $310,000 that will be forgiven at the completion of the IPO.  Cite the
relevant accounting literature to support your accounting.

Risk F actors , page 11

“We have completed and will in the future complete related party transactions …,” page 12

2. Please describe for us the related party transactions you did not conduct on an arm’s
length b asis how you accounted for them.

Walter Klemp
Moleculin Biotech, Inc.
March 4, 2016
Page 2

  “The intellectual property rights we have licensed from MD Anderson…, ” page 18

3. Please restore your deleted statement about your knowledge of any funding agreements
that would impinge on the IP rights you have licensed from MD Anderson and specify
the extent of your due diligence to confirm this fact.

Use of P roceeds, page 25

4. Please indicate the extent to which you contemplate using offering proceeds to pay down
existing debt or to satisfy obligations, such as yo ur installment payments to MD
Anderson for past due fees, discussed on page F -18.

Management’s Discussion and Analysis of Financial Condition …, page 37

Critical Accounting Policies and Significant Judgments and Estimates, page 38

5. In your re sponse to comment 1 7, you state that you estimate the fair value of your
common stock using the most recent selling price available.  Please tell us the date, the
number of shares sold for cash, your relationship to the purchaser (s), and the stock price
to support your debt conversion price of $0.1299 during August and September 2015 and
$0.20 during October and December 2015.  Furthermore, to the extent your stock was
sold to a related party, please tell us how you determined that such transaction was
conducted at an arm’s l ength.

6. Please explain the difference between the most recent common stock valuation of $0.20
on December 30, 2015 and the midpoint of your current estimated IPO price of $5.50.

Research and Development Expense, page 39

7. Tell us why you believe patent prosecution fees are appropriately classified as research
and development  expense .

Business, page 43

Our Drug Candidates , page 44

Annamycin, p age 4 4

8. We refer to our prior comment 19. Please revise your prospectus to disclose:

 the reason given by Callisto in its public  filings for terminating further
development of Annamycin as a treatment for adult acute leukemia was that the
clinical data did not support further clinical evaluation;

Walter Klemp
Moleculin Biotech, Inc.
March 4, 2016
Page 3

  the clinical data which you intend to use to apply for a new IND and on which
you are basing your assessment of Annamycin’s therapeutic potential are the data
generated by Callisto in its earlier clinical trials, completed in 2007; and

 the basis of your decision to move forward with the development of Annamycin
notwithstanding Calli sto’s prior evaluation of this product candidate.

9. In addition, we note your disclosure that Annamycin “demonstrated efficacy” in the prior
Phase I study and “demonstrated a similar efficacy profile” in the subsequent Phase I/II
study. However, the focus of the studies to which you refer was dose tolerance and
patient safety, not product efficacy. As you acknowledge in your response to comment
19, the trials were “not designed to reach statistical significance” and therefore would not
satisfy the FDA ’s standards for proof of efficacy. In fact, the study you cite concludes
only that Annamycin “has encouraging anti -leukemic activity,” which is not sufficient to
support a claim of efficacy. Accordingly, please remove from your prospectus any
statements o r suggestion that Annamycin was effective or demonstrated efficacy in prior
clinical trials, as the concept of “efficacy” is well -defined by the FDA and generally
understood in the pharmaceutical industry to refer to measurable proof of a product’s
effecti veness sufficient to support regulatory approval.

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 Secur ities Act of 193 3 and
all applicable Securities  Act rules require.   Since the company and its management are in
possession of all facts relating to a company’s disclosure, they are responsible for the accuracy
and adequacy of the disclosures they have made .

Notwithstanding our comments, in the event you request acceleration of the effective date
of the pending regist ration statement , please provide  a written statement from the company
acknowledging that:

 should the Commission or the staff, acting pursua nt to delegated authority, declare the
filing effective, it does not foreclose the Commission from taking any action with respect
to the filing;

 the action of the Commission or the staff, acting pursuant to delegated authority, in
declaring the filing effective, does not relieve the company from its full responsibility for
the adequacy and accuracy of the disclosure in the filing; and

 the company  may not assert staff comments and the declaration of effectiveness as a
defense in any proceeding initiated by the Commission or any person under the federal
securities laws of the United States.

Walter Klemp
Moleculin Biotech, Inc.
March 4, 2016
Page 4

 Please refer to Rules 460 and 461 regarding requests for  acceleration .  We will consider a
written request for acceleration of the effective date of the registration statement as confirmation
of the fact that those requesting acceleration are aware of their respective responsibilities under
the Securities Act o f 1933 and the Securities Exchange Act of 1934 as they relate to the proposed
public offering of the securities specified in the above registration statement.  Please allow
adequate time  for us to review any amendment prior to the requested effective date of the
registration statement.

You may contact Keira Nakada at (202) 551 -3659 or Lisa Vanjoske at (202) 551 -3614 if
you have questions regarding comments on the financial statements and related matters.   Please
contact Scot F oley at (202) 551 -3383, Daniel Greenspan  at (202) 551 -3623 or me at (202) 551 -
3675 with any other questions.

Sincerely,

 /s/ Mary Beth Breslin for

Suzanne Hayes
Assistant Director
Office of Healthcare and Insurance

cc:   Cavas S. Pavri , Esq.