CTMX

SEC source: 0001140361-16-086602 · doc1.xml · nonDerivative · entry 2

SHANNON TIMOTHY M · CIK 0001207114 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 3,868,125

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.00 - $11.44, inclusive. The Reporting Person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The shares are held directly by Canaan IX L.P. The Reporting Person is a non-managing member of Canaan Partners IX LLC, the general partner of Canaan IX L.P. The Reporting Person does not have voting, investment or dispositive power over any of the shares directly held by Canaan IX L.P. and disclaims beneficial ownership of the shares except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the shares for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

SEC source: 0000899243-16-033335 · doc4.xml · nonDerivative · entry 2

Canaan IX L.P. · CIK 0001538676 · Director · 10% owner

Canaan Partners IX LLC · CIK 0001654586 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,868,125

F3 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.00 - $11.44, inclusive. The reporting persons undertake to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (3) of this Form 4.

F2 · ownership.nature: The shares are held directly by Canaan IX L.P. (the "Canaan Fund"). Canaan Partners IX LLC ("Canaan IX" and together with the Canaan Fund, the "Canaan Entities") is the sole general partner of the Canaan Fund, and each may be deemed to have sole voting, investment and dispositive power with respect to the shares held by the Canaan Fund. Timothy Shannon, a non-managing member of Canaan IX, serves as representative of the Canaan Entities on the issuer's board of directors. Canaan IX disclaims Section 16 beneficial ownership of the securities held by the Canaan Fund, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001140361-16-086602 · doc1.xml · nonDerivative · entry 1

SHANNON TIMOTHY M · CIK 0001207114 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 3,903,516

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.00 - $11.24, inclusive. The Reporting Person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The shares are held directly by Canaan IX L.P. The Reporting Person is a non-managing member of Canaan Partners IX LLC, the general partner of Canaan IX L.P. The Reporting Person does not have voting, investment or dispositive power over any of the shares directly held by Canaan IX L.P. and disclaims beneficial ownership of the shares except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the shares for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

SEC source: 0000899243-16-033335 · doc4.xml · nonDerivative · entry 1

Canaan IX L.P. · CIK 0001538676 · Director · 10% owner

Canaan Partners IX LLC · CIK 0001654586 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,903,516

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.00 - $11.24, inclusive. The reporting persons undertake to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (1) of this Form 4.

F2 · ownership.nature: The shares are held directly by Canaan IX L.P. (the "Canaan Fund"). Canaan Partners IX LLC ("Canaan IX" and together with the Canaan Fund, the "Canaan Entities") is the sole general partner of the Canaan Fund, and each may be deemed to have sole voting, investment and dispositive power with respect to the shares held by the Canaan Fund. Timothy Shannon, a non-managing member of Canaan IX, serves as representative of the Canaan Entities on the issuer's board of directors. Canaan IX disclaims Section 16 beneficial ownership of the securities held by the Canaan Fund, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001140361-16-085852 · doc1.xml · nonDerivative · entry 1

SHANNON TIMOTHY M · CIK 0001207114 · Director

10b5-1 filing: Not disclosed

Ownership: Indirect · See footnote

Disclosed balance after: 3,930,651

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.00 - $11.15, inclusive. The Reporting Person undertakes to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

F2 · ownership.nature: The shares are held directly by Canaan IX L.P. The Reporting Person is a non-managing member of Canaan Partners IX LLC, the general partner of Canaan IX L.P. The Reporting Person does not have voting, investment or dispositive power over any of the shares directly held by Canaan IX L.P. and disclaims beneficial ownership of the shares except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that the Reporting Person is the beneficial owner of the shares for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose.

SEC source: 0000899243-16-033178 · doc4.xml · nonDerivative · entry 1

Canaan IX L.P. · CIK 0001538676 · Director · 10% owner

Canaan Partners IX LLC · CIK 0001654586 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,930,651

F1 · price: The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $11.00 - $11.15, inclusive. The reporting persons undertake to provide to the issuer, any security holder of the issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in footnote (1) of this Form 4.

F2 · ownership.nature: The shares are held directly by Canaan IX L.P. (the "Canaan Fund"). Canaan Partners IX LLC ("Canaan IX" and together with the Canaan Fund, the "Canaan Entities") is the sole general partner of the Canaan Fund, and each may be deemed to have sole voting, investment and dispositive power with respect to the shares held by the Canaan Fund. Timothy Shannon, a non-managing member of Canaan IX, serves as representative of the Canaan Entities on the issuer's board of directors. Canaan IX disclaims Section 16 beneficial ownership of the securities held by the Canaan Fund, except to the extent of its pecuniary interest therein, if any.

SEC source: 0000899243-16-033012 · doc4.xml · nonDerivative · entry 1

THIRD ROCK VENTURES LP · CIK 0001408591 · 10% owner

Third Rock Ventures GP, L.P. · CIK 0001578976 · 10% owner

TRV GP, LLC · CIK 0001578973 · 10% owner

LEVIN MARK J · CIK 0001180428 · 10% owner

STARR KEVIN P · CIK 0001192603 · 10% owner

TEPPER ROBERT I · CIK 0001192595 · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 7,670,348

F1 · kind: On November 7, 2016, Third Rock Ventures, L.P. ("TRV") distributed, for no consideration, 1,000,000 shares of Common Stock of the Issuer (the "Shares") to its limited partners and to Third Rock Ventures GP, L.P. ("TRV GP"), the general partner of TRV, representing each such partner's pro rata interest in such Shares. On the same date, TRV GP distributed, for no consideration, the Shares it received in the distribution by TRV to its partners, representing each such partner's pro rata interest in such Shares. All of the aforementioned distributions were made in accordance with the exemptions afforded by Rules 16a-13 and 16a-9 of the Securities Exchange Act of 1934, as amended.

F1 · price: On November 7, 2016, Third Rock Ventures, L.P. ("TRV") distributed, for no consideration, 1,000,000 shares of Common Stock of the Issuer (the "Shares") to its limited partners and to Third Rock Ventures GP, L.P. ("TRV GP"), the general partner of TRV, representing each such partner's pro rata interest in such Shares. On the same date, TRV GP distributed, for no consideration, the Shares it received in the distribution by TRV to its partners, representing each such partner's pro rata interest in such Shares. All of the aforementioned distributions were made in accordance with the exemptions afforded by Rules 16a-13 and 16a-9 of the Securities Exchange Act of 1934, as amended.

F2 · ownership.direct: These shares are directly held by TRV. The general partner of TRV is TRV GP. The general partner of TRV GP is TRV GP, LLC ("TRV GP LLC"). The individual managers of TRV GP LLC are Mark Levin ("Levin"), Kevin Starr ("Starr") and Dr. Robert Tepper ("Tepper"). Each of TRV GP, TRV GP LLC, Levin, Starr and Tepper disclaims beneficial ownership of the shares except to the extent of its or his pecuniary interest therein, if any, and this report shall not be deemed an admission that it or he is the beneficial owner of such shares.

SEC source: 0000899243-16-033011 · doc4.xml · nonDerivative · entry 1

Exter Neil · CIK 0001620014 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 0

F1 · kind: On November 7, 2016, Third Rock Ventures, L.P. ("TRV") distributed, for no consideration, 1,000,000 shares of Common Stock of the Issuer (the "Shares") to its limited partners and to Third Rock Ventures GP, L.P. ("TRV GP"), the general partner of TRV, representing each such partner's pro rata interest in such Shares. On the same date, TRV GP distributed, for no consideration, the Shares it received in the distribution by TRV to its partners, representing each such partner's pro rata interest in such Shares. All of the aforementioned distributions were made in accordance with the exemptions afforded by Rules 16a-13 and 16a-9 of the Securities Exchange Act of 1934, as amended.

F1 · price: On November 7, 2016, Third Rock Ventures, L.P. ("TRV") distributed, for no consideration, 1,000,000 shares of Common Stock of the Issuer (the "Shares") to its limited partners and to Third Rock Ventures GP, L.P. ("TRV GP"), the general partner of TRV, representing each such partner's pro rata interest in such Shares. On the same date, TRV GP distributed, for no consideration, the Shares it received in the distribution by TRV to its partners, representing each such partner's pro rata interest in such Shares. All of the aforementioned distributions were made in accordance with the exemptions afforded by Rules 16a-13 and 16a-9 of the Securities Exchange Act of 1934, as amended.

F2 · ownership.direct: The reporting person is a partner of TRV GP, which is the general partner of TRV. The reporting person disclaims beneficial ownership over the shares held by TRV, except to the extent of his pecuniary interest therein, if any, and this report shall not be deemed an admission that he is the beneficial owner of such shares.

SEC source: 0000899243-16-031602 · doc4.xml · nonDerivative · entry 1

Canaan IX L.P. · CIK 0001538676 · Director · 10% owner

Canaan Partners IX LLC · CIK 0001654586 · Director · 10% owner

Joint disclosure: these amounts are not allocated separately to each reporting owner.

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnote

Disclosed balance after: 3,944,381

F1 · kind: On October 11, 2016, Canaan IX L.P. (the "Canaan Fund") distributed, for no consideration, 300,000 shares of Common Stock of the issuer (the "Shares") to its limited partners and to Canaan Partners IX LLC ("Canaan IX" and, together with the Canaan Fund, the "Canaan Entities"), the general partner of the Canaan Fund, representing each such partner's pro rata interest in the shares held by the Canaan Fund. On the same date, Canaan IX distributed, for no consideration, the Shares it received from the distribution to its members in an amount equal to each such member's pro rata interest in the Shares. The aforementioned distributions were made in accordance with the exemptions afforded by Rule 16a-13 and Rule 16a-9 of the Securities Exchange Act of 1934, as amended.

F1 · price: On October 11, 2016, Canaan IX L.P. (the "Canaan Fund") distributed, for no consideration, 300,000 shares of Common Stock of the issuer (the "Shares") to its limited partners and to Canaan Partners IX LLC ("Canaan IX" and, together with the Canaan Fund, the "Canaan Entities"), the general partner of the Canaan Fund, representing each such partner's pro rata interest in the shares held by the Canaan Fund. On the same date, Canaan IX distributed, for no consideration, the Shares it received from the distribution to its members in an amount equal to each such member's pro rata interest in the Shares. The aforementioned distributions were made in accordance with the exemptions afforded by Rule 16a-13 and Rule 16a-9 of the Securities Exchange Act of 1934, as amended.

F2 · ownership.nature: The shares are held directly by the Canaan Fund. Canaan IX, is the sole general partner of the Canaan Fund, and each may be deemed to have sole voting, investment and dispositive power with respect to the shares held by the Canaan Fund. Timothy Shannon, a non-managing member of Canaan IX, serves as representative of the Canaan Entities on the issuer's board of directors. Canaan IX disclaims Section 16 beneficial ownership of the securities held by the Canaan Fund, except to the extent of its pecuniary interest therein, if any.

SEC source: 0001140361-16-081383 · doc1.xml · derivative · entry 2

Goeltz II Robert C. · CIK 0001653881 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 241,675

Underlying: Common Stock · 4,000 shares

Expires 2025-05-06

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

F1 · derivative.exercise_date: This option vests 25% on May 4, 2016, and the remaining 75% vests in 36 substantially equal monthly installments thereafter, with each additional installment vesting on the last day of the month, except the final installment, which shall vest on May 4, 2019.

SEC source: 0001140361-16-081383 · doc1.xml · nonDerivative · entry 1

Goeltz II Robert C. · CIK 0001653881 · Chief Financial Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 6,000

Exercise/conversion can include RSU settlement. Transaction price and option strike are different fields; a missing price is not zero. Derivative and underlying rows can describe the same event.

SEC source: 0001140361-16-080948 · doc1.xml · derivative · entry 2

McCarthy Sean A. · CIK 0001654058 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 122,424

Underlying: Common Stock · 122,424 shares

Expires 2025-02-08

F2 · derivative.exercise_date: On February 9, 2015, the Reporting Person was granted an option to purchase 122,424 shares of Common Stock, as adjusted for the 1-for-62.997 reverse stock split effected prior to the Issuer's initial public offering, to vest in full upon achievement of a certain performance-based milestone (the "Performance Option"). On September 26, 2016, the performance milestone was achieved resulting in 100% of the Performance Option vesting.

SEC source: 0001140361-16-080948 · doc1.xml · derivative · entry 1

McCarthy Sean A. · CIK 0001654058 · Director · President and CEO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 48,379

Underlying: Common Stock · 48,379 shares

Expires 2023-02-25

F1 · derivative.exercise_date: On February 26, 2013, the Reporting Person was granted an option to purchase 96,758 shares of Common Stock, as adjusted for the 1-for-62.997 reverse stock split effected prior to the Issuer's initial public offering, to vest in two equal tranches upon achievement of certain performance-based milestones (the "Performance Option"). 50% of the Performance Option previously vested upon achievement of the first performance milestone. On September 26, 2016, the second performance milestone was achieved resulting in vesting of the remaining 50% of the Performance Option.

SEC source: 0001140361-16-080947 · doc1.xml · derivative · entry 1

Kavanaugh William Michael · CIK 0001578767 · CSO, Head Res.&Non-Clin. Dev.

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 48,368

Underlying: Common Stock · 48,368 shares

Expires 2025-05-06

F1 · derivative.exercise_date: On May 7, 2015, the Reporting Person was granted an option to purchase 96,736 shares of Common Stock, as adjusted for the 1-for-62.997 reverse stock split effected prior to the Issuer's initial public offering, to vest in two equal tranches upon achievement of certain performance-based milestones (the "Performance Option"). On September 26, 2016, the first performance milestone was achieved resulting in 50% of the Performance Option vesting.