PTI Proteostasis Therapeutics Inc

CUSIP No.    74373B109

13D

Page     2      of     9    Pages

Schedule 13D

Item 1. Security and Issuer.

This Amendment No. 3 (“Amendment No. 3”) to Schedule 13D amends and supplements the statement on Schedule 13D originally filed on February 26, 2016, Amendment No. 1 thereto filed on September 20, 2016 (“Amendment No. 1”) and Amendment No. 2 thereto filed on December 21, 2017 (“Amendment No. 2”) relating to the common stock, $.001 par value (the “Common Stock”) of Proteostasis Therapeutics, Inc. (the “Issuer”) having its principal executive office at 80 Guest Street, Suite 500, Boston, Massachusetts 02135.

Certain terms used but not defined in this Amendment No. 3 have the meanings assigned thereto in the Schedule 13D (and Amendment No. 1 and Amendment No. 2 thereto).  Except as specifically provided herein, this Amendment No. 3 does not modify any of the information previously reported on the Schedule 13D (and Amendment No. 1 and Amendment No. 2 thereto).

Item 2. Identity and Background.

This statement is being filed by:

(a) New Enterprise Associates 12, Limited Partnership (“NEA 12”);

(b) NEA Partners 12, Limited Partnership (“NEA Partners 12”), which is the sole general partner of NEA 12; and NEA 12 GP, LLC (“NEA 12 LLC” and, together with NEA Partners 12, the “Control Entities”), which is the sole general partner of NEA Partners 12; and

(c) M. James Barrett (“Barrett”), Peter J. Barris (“Barris”), Forest Baskett (“Baskett”), Patrick J. Kerins (“Kerins”) and Scott D. Sandell (“Sandell”) (together, the “Managers”).  The Managers are the managers of NEA 12 LLC.

The persons named in this Item 2 are referred to individually herein as a “Reporting Person” and collectively as the “Reporting Persons.”

The address of the principal business office of NEA 12 and each Control Entity is New Enterprise Associates, 1954 Greenspring Drive, Suite 600, Timonium, MD 21093.  The address of the principal business office of each of Barrett, Barris and Kerins is New Enterprise Associates, 5425 Wisconsin Avenue, Suite 800, Chevy Chase, MD 20815.  The address of the principal business office of Baskett and Sandell is New Enterprise Associates, 2855 Sand Hill Road, Menlo Park, California 94025.

The principal business of NEA 12 is to invest in and assist growth-oriented businesses located principally in the United States.  The principal business of NEA Partners 12 is to act as the sole general partner of NEA 12.  The principal business of NEA 12 LLC is to act as the sole general partner of NEA Partners 12.  The principal business of each of the Managers is to manage the Control Entities, NEA 12 and a number of affiliated partnerships with similar businesses.

During the five years prior to the date hereof, none of the Reporting Persons has been convicted in a criminal proceeding or has been a party to a civil proceeding ending in a judgment, decree or final order enjoining future violations of, or prohibiting or mandating activities subject to, federal or state securities laws or finding any violation with respect to such laws.

NEA 12 and NEA Partners 12 are limited partnerships organized under the laws of the State of Delaware.  NEA 12 LLC is a limited liability company organized under the laws of the State of Delaware.  Each of the Managers is a United States citizen.

CUSIP No.    74373B109

13D

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Item 4. Purpose of Transaction.

Not applicable.

Each of the Reporting Persons has ceased to own beneficially five percent or more of the Issuer’s Common Stock.

Item 7. Material to be Filed as Exhibits.

Exhibit 1 – Agreement regarding filing of joint Schedule 13D.

Exhibit 2 – Power of Attorney regarding filings under the Securities Exchange Act of 1934, as amended.

SIGNATURE

After reasonable inquiry and to the best of its knowledge and belief, each of the undersigned certifies that the information set forth in this statement is true, complete and correct.

EXECUTED this 6^th day of December, 2019.

NEW ENTERPRISE ASSOCIATES 12, Limited Partnership

By:                    *                           

Peter J. Barris

Manager

NEA PARTNERS 12, Limited Partnership

By:                     *                           

       Peter J. Barris

       Manager

NEA 12 GP, LLC

By:                             *                          

Peter J. Barris

Manager

M. James Barrett

Peter J. Barris

Forest Baskett

Patrick J. Kerins

Scott D. Sandell

*/s/ Sasha O. Keough                     

Sasha O. Keough

As attorney-in-fact

This Amendment No. 3 to Schedule 13D was executed by Sasha O. Keough on behalf of the individuals listed above pursuant to a Power of Attorney a copy of which is attached as Exhibit 2.

CUSIP No.    74373B109

13D

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EXHIBIT 1

AGREEMENT

Pursuant to Rule 13d-1(k)(1) under the Securities Exchange Act of 1934, the undersigned hereby agree that only one statement containing the information required by Schedule 13D need be filed with respect to the ownership by each of the undersigned of shares of stock of Proteostasis Therapeutics, Inc.

EXECUTED this 6^th day of December, 2019.

This Agreement relating to Schedule 13D was executed by Sasha O. Keough on behalf of the individuals listed above pursuant to a Power of Attorney a copy of which is attached hereto as Exhibit 2.

EXHIBIT 2

POWER OF ATTORNEY

KNOW ALL MEN BY THESE PRESENTS, that the undersigned hereby constitutes and appoints Louis S. Citron, Timothy Schaller, Sasha Keough and Stephanie Brecher, and each of them, with full power to act without the others, his or her true and lawful attorney-in-fact, with full power of substitution, to sign any and all instruments, certificates and documents that may be necessary, desirable or appropriate to be executed on behalf of himself as an individual or in his or her capacity as a direct or indirect general partner, director, officer or manager of any partnership, corporation or limited liability company, pursuant to section 13 or 16 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and any and all regulations promulgated thereunder, and to file the same, with all exhibits thereto, and any other documents in connection therewith, with the Securities and Exchange Commission, and with any other entity when and if such is mandated by the Exchange Act or by the Financial Industry Regulatory Authority, granting unto said attorney-in-fact full power and authority to do and perform each and every act and thing necessary, desirable or appropriate, fully to all intents and purposes as he or she might or could do in person, thereby ratifying and confirming all that said attorney-in-fact, or his or her substitutes, may lawfully do or cause to be done by virtue hereof.

IN WITNESS WHEREOF, this Power of Attorney has been signed as of the 13th day of March, 2017.

/s/ M. James Barrett                     

M. James Barrett

/s/ Peter J. Barris                           

Peter J. Barris

/s/ Forest Baskett                          

Forest Baskett

/s/ Ali Behbahani                          

Ali Behbahani

/s/ Colin Bryant                            

Colin Bryant

/s/ Carmen Chang                         

Carmen Chang

/s/ Anthony A. Florence, Jr.          

Anthony A. Florence, Jr.

/s/ Carol G. Gallagher                   

Carol G. Gallagher

/s/ Dayna Grayson                        

Dayna Grayson

/s/ Patrick J. Kerins                       

Patrick J. Kerins

/s/ P. Justin Klein                          

P. Justin Klein

CUSIP No.    74373B109

13D

Page     9      of     9    Pages

/s/ Vanessa Larco                          

Vanessa Larco

/s/ Joshua Makower                      

Joshua Makower

/s/ Mohamad H. Makhzoumi        

Mohamad H. Makhzoumi

/s/ Edward T. Mathers                   

Edward T. Mathers

/s/ David M. Mott                         

David M. Mott

/s/ Sara M. Nayeem                      

Sara M. Nayeem

/s/ Jason R. Nunn                          

Jason R. Nunn

/s/ Gregory Papadopoulos            

Gregory Papadopoulos

/s/ Chetan Puttagunta                    

Chetan Puttagunta

/s/ Jon Sakoda                               

Jon Sakoda

/s/ Scott D. Sandell                       

Scott D. Sandell

/s/ A. Brooke Seawell                   

A. Brooke Seawell

/s/ Peter W. Sonsini                      

Peter W. Sonsini

/s/ Melissa Taunton                       

Melissa Taunton

/s/ Frank M. Torti                         

Frank M. Torti

/s/ Ravi Viswanathan                    

Ravi Viswanathan

/s/ Paul E. Walker                         

Paul E. Walker

/s/ Rick Yang                                

Rick Yang