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: 3235-0287
Estimated average burden
hours per response: 0.5
Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
1. Name and Address of Reporting Person*
Steen Marten

(Last) (First) (Middle)


(City) (State) (Zip)
2. Issuer Name and Ticker or Trading Symbol
Strongbridge Biopharma plc [ SBBP ]
5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
X Director 10% Owner
Officer (give title below) Other (specify below)
3. Date of Earliest Transaction (Month/Day/Year)
4. 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 Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3) 2. Transaction Date (Month/Day/Year) 2A. Deemed Execution Date, if any (Month/Day/Year) 3. Transaction Code (Instr. 8) 4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5) 5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4) 6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 7. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V Amount (A) or (D) Price
Ordinary Shares 05/14/2021 F 19,004(1) D $2.35 41,914 I By HealthCap VI, L.P.(2)
Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned
(e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3) 2. Conversion or Exercise Price of Derivative Security 3. Transaction Date (Month/Day/Year) 3A. Deemed Execution Date, if any (Month/Day/Year) 4. Transaction Code (Instr. 8) 5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5) 6. Date Exercisable and Expiration Date (Month/Day/Year) 7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4) 8. Price of Derivative Security (Instr. 5) 9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4) 10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4) 11. Nature of Indirect Beneficial Ownership (Instr. 4)
Code V (A) (D) Date Exercisable Expiration Date Title Amount or Number of Shares
Explanation of Responses:
1. Shares withheld by the Issuer to satisfy taxes payable in connection with the vesting of previously awarded restricted stock units.
2. Based on his affiliation with HealthCap VI, L.P., the Reporting Person may be deemed the beneficial owner of these securities. The Reporting Person expressly disclaims beneficial ownership over these securities except to the extent of his pecuniary interest therein.
Exhibit List: Exhibit 24 - Power of Attorney
/s/ Judith Goldberg, as attorney-in-fact 05/18/2020
** 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 4 (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.
                               POWER OF ATTORNEY

           KNOW  ALL  PERSONS  BY  THESE  PRESENTS  that  the undersigned hereby
constitutes, designates and appoints each of Stephen J. Long, Richard S.
Kollender and Judith  Goldberg  as such person's true and lawful
attorneys-in-fact and agents, each  with  full  power of substitution and
resubstitution and full power to act alone  and without the other, for the
undersigned and in the undersigned's name, place and stead, in any and all
capacities, to:

        (a)  prepare, execute in the undersigned's name and on the undersigned's
behalf,  and submit to the U.S. Securities and Exchange Commission (the "SEC") a
Form ID (or any successor form), including amendments thereto, and any other
documents necessary or appropriate to obtain codes and passwords enabling the
undersigned to make electronic filings with the SEC of reports required by
Section 16(a) or any rule or regulation of the SEC promulgated thereunder;

        (b)  execute  for and on behalf of the undersigned, in the undersigned's
capacity  as  an  officer  and/or  director  of  Strongbridge Biopharma plc (the
"Company"), Forms 3, 4, and 5 in accordance with Section 16(a) of the Securities
Exchange Act of 1934 and the rules thereunder (or any successor forms);

        (c) 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 Form 3, 4,
or  5, complete and execute any amendment or amendments thereto, and timely file
such form with the SEC and any stock exchange or similar authority; and

        (d)  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 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 full
power  and  authority  to  do and perform any and every act and thing whatsoever
requisite,  necessary, or proper 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 such
attorney-in-fact,  or  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  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  16 of the Securities
Exchange Act of 1934.

           This  Power  of  Attorney shall remain in full force and effect until
the  undersigned is no longer required to file Forms 3, 4, and 5 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, except that in respect of any person herein
appointed  as  an  attorney-in-fact  of  the undersigned, this Power of Attorney
shall  be  revoked  and  shall cease to be effective immediately with respect to
such  person  at  such time as such person shall no longer be employed by any of
the Company and its subsidiaries.

           IN  WITNESS  WHEREOF, the undersigned has executed this instrument as
of the 23rd day of March, 2021.

                                          By:/s/ Marten Steen
                                          Name: Marten Steen