Washington, D.C. 20549


Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940
OMB Number: 3235-0104
Estimated average burden
hours per response: 0.5
1. Name and Address of Reporting Person*
Rossi Christina

(Last) (First) (Middle)


(City) (State) (Zip)
2. Date of Event Requiring Statement (Month/Day/Year)
3. Issuer Name and Ticker or Trading Symbol
Blueprint Medicines Corp [ BPMC ]
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
Director 10% Owner
X Officer (give title below) Other (specify below)
Chief Commercial Officer
5. If Amendment, Date of Original Filed (Month/Day/Year)
6. Individual or Joint/Group Filing (Check Applicable Line)
X Form filed by One Reporting Person
Form filed by More than One Reporting Person
Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4) 2. Amount of Securities Beneficially Owned (Instr. 4) 3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 4. Nature of Indirect Beneficial Ownership (Instr. 5)
Table II - Derivative Securities Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4) 2. Date Exercisable and Expiration Date (Month/Day/Year) 3. Title and Amount of Securities Underlying Derivative Security (Instr. 4) 4. Conversion or Exercise Price of Derivative Security 5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5) 6. Nature of Indirect Beneficial Ownership (Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Explanation of Responses:
Exhibit 24 - Limited Power of Attorney
No securities are beneficially owned.
/s/ Christopher Frankenfield, Attorney-in-Fact 11/05/2018
** Signature of Reporting Person Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.
                           LIMITED POWER OF ATTORNEY

      The  undersigned  hereby  constitutes  and appoints each of Tracey McCain,
Christopher  Frankenfield,  Ariel  Hurley  and  Michael Landsittel, and  each of
them individually, and  with full  power of substitution, the undersigned's true
and lawful attorney-in-fact to:

      (1)   Complete  and  execute  for and on behalf of the undersigned, in the
            undersigned's  capacity  as  an officer, director and/or ten percent
            (10%)  shareholder  of  Blueprint  Medicines Corporation, a Delaware
            corporation  (the  "Company"), any and all instruments, certificates
            and  documents  required to be executed on behalf of the undersigned
            as  an  individual  or  on  behalf  of  the undersigned's company or
            partnership,  as the case may be, pursuant to Section 13 and Section
            16 of the Securities Exchange Act of 1934, as amended (the "Exchange
            Act") or the rules and regulations thereunder;

      (2)   Do and perform any and all acts for and on behalf of the undersigned
            which may be necessary or desirable to complete and execute any such
            instruments, certificates or documents required to be filed pursuant
            to  Sections  13  and  16  of  the  Exchange  Act  or  the  rules or
            regulations  thereunder  and  timely file such forms with the United
            States  Securities and Exchange
 Commission and any stock exchange or
            similar authority; and

      (3)   Take  any other action of any type whatsoever in connection with the
            foregoing  which, in the opinion of such attorney-in-fact, may be of
            benefit  to,  in  the  best interest of, or legally required by, the
            undersigned,  it being understood that the documents executed by any
            such  attorney-in-fact on behalf of the undersigned pursuant to this
            Power of Attorney shall be in such form and shall contain such terms
            and   conditions  as  such  attorney-in-fact  may  approve  in  such
            attorney-in-fact's discretion.

      The  undersigned  hereby  grants  to  each  such  attorney-in-fact, acting
singly,  full  power  and authority to do and perform any and every act which is
necessary,  proper  or desirable to be done in the exercise of any of the rights
and  powers  herein  granted,  as  fully  to  all  intents  and  purposes as the
undersigned  might  or  could  do  if  personally  present,  with  full power of
substitution  or  revocation,  hereby ratifying and confirming all that any such
attorney-in-fact,  or  any  such  attorney-in-fact's  substitute or substitutes,
shall  lawfully  do  or cause to be done by virtue of this Power of Attorney and
the rights and powers herein granted.

      The undersigned acknowledges that each of the foregoing attorneys-in-fact,
in serving in such capacity at the request of the undersigned, are not assuming,
nor is the Company assuming, any of the undersigned's responsibilities to comply
with  Section  13  or Section 16 of the Exchange Act or the rules or regulations
thereunder. The undersigned hereby agrees to indemnify each attorney-in-fact and
the  Company  from and against any demand, damage, loss, cost or expense arising
from  any  false  or  misleading information provided by the undersigned to such
attorney-in fact.

      This  Power  of  Attorney  shall remain in full force and effect until the
undersigned  is  no  longer  required  to file any instruments, certificates and
documents  pursuant  to  Section  13  and 16 of the Exchange Act or the rules or
regulations  thereunder  with  respect  to  the  undersigned's  holdings  of and
transactions  in securities issued by the Company, unless earlier revoked by the
undersigned in a signed writing delivered to the foregoing attorneys-in-fact.

      IN  WITNESS  WHEREOF, the undersigned has caused this Power of Attorney to
be executed as of October 29, 2018.

                                   By:   /s/ Christina Rossi
                                   Name: Christina Rossi