United States securities and exchange commission logo

                            August 27, 2020

       Frederic Guerard, Pharm.D.
       President and Chief Executive Officer
       Graybug Vision, Inc.
       275 Shoreline Drive, Suite 450
       Redwood City, CA 94065

                                                        Re: Graybug Vision,
                                                            Draft Registration
Statement on Form S-1
                                                            Submitted July 31,
                                                            CIK No. 0001534133

       Dear Dr. Guerard:

              We have reviewed your draft registration statement 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 providing the requested
information and either submitting
       an amended draft registration statement or publicly filing your
registration statement on
       EDGAR. 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

             After reviewing the information you provide in response to these
comments and your
       amended draft registration statement or filed registration statement, we
may have additional

       Draft Registration Statement on Form S-1 submitted July 31, 2020

       Our Pipeline, page 3

   1.                                                   Please shorten the
arrows in your pipeline table to more precisely indicate the
                                                        development status of
each product candidate. As one example, we note that you are
                                                        currently conducting
IND-enabling activities for GB-401 and expect to begin a Phase 1/2a
                                                        trial in the second
half of 2021, yet the arrow indicates that you are already in Phase 1
       Our Lead Program GB-102, page 4

   2.                                                   We note your statements
on page 4 that GB-102 met its primary endpoint of safety and
                                                        tolerability in the
ADAGIO trial and based on the data from ADAGIO you initiated a
 Frederic Guerard, Pharm.D.
FirstName  LastNameFrederic Guerard, Pharm.D.
Graybug Vision,  Inc.
August  27, NameGraybug
            2020         Vision, Inc.
Page 2 27, 2020 Page 2
FirstName LastName
         Phase 2b ALTISSIMO trial. Balance your disclosure here by disclosing
that you
         terminated the development of the GB-102 2 mg dose in all of your
clinical trials based on
         your safety analysis of your Phase 2a clinical trial of GB-102 in 21
patients with ME
         secondary to DME and RVO.
Differentiation of our product candidates, page 5

3.       We note your statements throughout your filing that you believe GB-102
and GB-103 may
         potentially be a "first-in-class" intravitreal injection. Given the
early stage of
         development, and your statements that your results in your preclinical
studies may not be
         indicative of results obtained in later trials, these statements are
overly speculative and
         inappropriate. Please remove these statements from the descriptions of
your product
Implications of Being an Emerging Growth Company and a Smaller Reporting
Company, page 7

4.       Please supplementally provide us with copies of all written
communications, as defined in
         Rule 405 under the Securities Act, that you, or anyone authorized to
do so on your behalf,
         present to potential investors in reliance on Section 5(d) of the
Securities Act, whether or
         not they retain copies of the communications.
Risk Factors, page 13

5.       We note your references on page 21 and elsewhere that GB-102
demonstrated a
         "favorable safety and tolerability." Please revise your disclosure
here and throughout your
         prospectus to remove your characterization of GB-102 as safe, as a
determination of
         whether a product candidate is safe is solely within the authority of
the U.S. Food and
         Drug Administration and comparable regulatory bodies. We will not
object to statements
         that GB-102 was well tolerated or information about the number of
treatment related
         serious adverse events, but you should not state or imply that your
product candidate is
Use of Proceeds, page 65

6.       Please expand your first bullet to disclose the estimated proceeds to
be allocated to each of
         your target indications and product candidates and clarify the stage
of development you
         expect to be able to complete for each indication using the estimated
Management's Discussion and Analysis of Financial Condition and Results of
Results of Operations for years ended December 31, 2019 and 2018, page 78

7.       Reference your disclosure that personnel and professional service
costs increased in the
         year ended December 31, 2019 as compared to 2018 as a result of
changes in and
         additions to executive management in 2019. Please revise to disclose
the specific changes
         in and additions to executive management and quantify the impact of
each change on
         personnel and professional service costs. Explain how additions to
 Frederic Guerard, Pharm.D.
FirstName  LastNameFrederic Guerard, Pharm.D.
Graybug Vision,  Inc.
August  27, NameGraybug
            2020         Vision, Inc.
Page 3 27, 2020 Page 3
FirstName LastName
         management affected professional service costs.
Determination of Fair Value of Common Stock on Grant Dates, page 83

8.       We see that you issued 11.3 million stock options during the year
ended December 31,
         2019. Please revise to disclose the fair value of common stock that
was used during the
         the fiscal year and any subsequent interim period provided in the
financial statements to
         determine the fair value of the stock options. In that regard, provide
us the estimated
         offering price or range when it is available and explain to us the
reasons for significant
         differences between recent valuations of your common stock and the
estimated offering
Our Product Candidates
GB-102, page 95

9.       The illustrations provided on the bottom of page 97 and the top of
page 98 appear to
         contain text that is illegible. In addition, certain symbols appear in
the graphics without a
         legend such that it is unclear what they are depicting. Please revise
these figures
10.      Your duration of response graph on the bottom of page 98 does not
include a legend and it
         is unclear what the horizontal lines and the green and yellow dots
represent. Please revise
         your disclosure accordingly.
Phase 2b trial of GB-102 in patients with wet AMD, page 102

11.      Please revise to clarify whether the trial design changes of the
         including the primary endpoint of median time to first additional
anti-VEFG supportive
         therapy, were related to the termination of the 2mg dose in your
clinical trial programs. If
         the modifications were made for other reasons, please disclose the
Unmet Need, page 106

12.      We note your disclosure that 15% of glaucoma patients progress to
blindness within 20
         years of diagnosis. Please disclose the source for this information.
Our Future Development Plans, page 109

13.      We note your planned reliance on the 505(b)(2) approval pathway.
Please identify and
         describe the studies and results you intend to rely on to pursue this
Description of Capital Stock, page 154

14.      You disclose here and on pages 148 and F-31, that certain purchasers
of Series C
         preferred stock have the option to purchase additional shares upon the
achievement of
         certain development milestones. Please revise to describe such
milestones in greater
 Frederic Guerard, Pharm.D.
Graybug Vision, Inc.
August 27, 2020
Page 4
      detail, and if applicable, how they will be calculated. In addition,
please provide the term
      and expiration period of the option to purchase.
       You may contact Kristin Lochhead at 202-551-3664 or Lisa Vanjoske at
202-551-3614 if
you have questions regarding comments on the financial statements and related
matters. Please
contact Jason L. Drory at 202-551-8342 or Mary Beth Breslin at 202-551-3625
with any other

FirstName LastNameFrederic Guerard, Pharm.D.
                                                             Division of
Corporation Finance
Comapany NameGraybug Vision, Inc.
                                                             Office of Life
August 27, 2020 Page 4
cc:       Julia Forbess
FirstName LastName