SecProbe.io

Mail Stop 4720

December  15, 2015

Via E -mail
Mr. Shane Kovacs
Chief Financial  Officer
PTC Therapeutics, Inc.
100 Corporate Court
South Plainfield, New Jersey 07080

Re: PTC Therapeutics, Inc.
 Form 10-K for the Fiscal Year Ended December  31, 201 4
Filed March 2 , 2015
Form 10 -Q for the Quarterly Period Ended September 30, 2015
Filed November 9, 2015
 File No. 001-35969

Dear Mr. Kovacs :

We have limited our review of your filings to the financial statements and related
disclosures  and have the following comments .  In our comment s, we ask you to provide us with
information so we may better understand your disclosure.

Please respond to th ese comment s within 10 busine ss days by providing the requested
information or advis e us as soon as possible  when you will respond .  If you do not believe  that a
comment applies to your facts and circumstances, please tell us why in your response.

After reviewing your response to t hese comments , we may have additional comments.

Form 10 -K for the Fiscal Year Ended December 31, 201 4

Item 6.  Selected Financial Data, page 94

1. You present only three years of statements of operations data in your table.  As
information for 2011 was presented in your initial public offering registration statement
on Form S -1, File Number 333 -193677, please represent to us that you will include fiv e
years of information in your 2015 Form 10 -K as required by Item 301(a) of Regulation S -
K.  In addition, please represent that you will include the balance sheet information
required by Instruction 2 to Item 301 of Regulation S -K in your 2015 Form 10 -K.

Mr. Shane Kovacs
PTC Therapeutics, Inc.
Dece mber 15, 201 5
Page 2

Management’s Discussion and Analysis of Financial Condition and Results of Operations
Critical accounting policies and significant judgments and estimates
Inventories and Cost of Product Revenues, page 100

2. Please tell us why you have not capitalized a ny inventory costs for Translarna product
manufactured for sale in Europe under your conditional approval and reference for us the
authoritative literature you relied upon to support your accounting.  Please ensure your
response also addresses the followin g:
 Tell us the amount of inventory costs you charged to expense in each fiscal year.
 Tell us the amount of inventory costs you charged to expense prior to receipt of
conditional approval.
 Tell us why it is appropriate to charge inventory costs incurred aft er receipt of
conditional approval to research and development expenses.  Explain to us how the
ultimate commercial sale of this product meets the definition of research or
development under ASC 730 -10-20 by discovering new knowledge or translating that
knowledge into new products, processes or techniques.
 Tell us the amount of royalties and other miscellaneous selling costs, as indicated on
page 10 of your September 30, 2015 Form 10 -Q, associated with your product sales
that you have charged to research and development costs.  Explain to us how these
costs meet the definition of research or development .
 Tell us the amount of zero -cost inventory you have on hand in terms of units, the
number of units you have sold by reporting period through September 30, 2015 and
why you do not provide any indication of the amount of this inventory on hand in
your filings.
 Although you characterize the amount of cost of sales in 2014 as being insignificant,
tell us what the cost of sales for 2014 and each quarter in 2015 would have been if
you had not charged all your inventory costs to research and development expenses.
Tell us your consideration for disclosing these amounts and why it is apparently not
meaningful information for investors to understand the potential gro ss margins for
Translarna.

Form 10 -Q for the Quarterly Period Ended September 30, 2015

Notes to Consolidated Financial Statements
Note 2:  Summary of significant accounting policies
Revenue Recognition
Net Product Sales, page 11

3. Please tell us whether you grant the right of return to your Translarna customers.  If so,
please tell us the provisions of your return policy and demonstrate to us how you were
able to make reasonable estimates of returns as required by ASC 605 -15-25-1f in order to
record revenue upon product shipment effective January 1, 2015.  In this regard, you
disclose on page 4 of your 2014 Form 10 -K that Translarna is the first ever approved

Mr. Shane Kovacs
PTC Therapeutics, Inc.
Dece mber 15, 201 5
Page 3

 treatment for the underlying cause of nonsense mutation Duchenne muscular d ystrophy
and that you did not launch Translarna on a commercial basis until December 2014.

 We urge all persons who are responsible for the accuracy and adequacy of the disclosure
in the filing s to be certain that the filing s include all information the Securities Exchange Act of
1934 and all applicable Exchange 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 th ey have made.

 In responding t o our commen ts, please provide  a written statement from the company
acknowledging that:

 the company is responsible for the adequacy and accuracy of the disclosure in the filing s;
 staff comment s or changes to disclosu re in response to staff comment s do not foreclose
the Commission from taking any action with respect to the filing s; and
 the compa ny may not assert the staff comment s as a defense in any proceeding initiated
by the Commission or any person under the federal secu rities laws of the United States.

You may contact Mark Bru nhofer, Senior Staff Accountant, at (202) 551 -3638 or Sharon
Blume, Accounting Branch Chief, at (202) 551 -3474 if you have questions regarding the
comment s.  In this regard, do not hesitate to contact me at (202) 551 -3679 .

Sincerely,

/s/ Jim B. Rosenberg

Jim B. Rosenberg
Senior Assistant Chief Accountant
Office of Healthcare and Insurance