ALEC

SEC source: 0001209191-20-005043 · doc4.xml · derivative · entry 6

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 116,667

Underlying: Common Stock · 14,467 shares

Expires 2028-07-01

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.

F3 · derivative.exercise_date: One forty-eighth (1/48th) of the shares subject to the option vested on August 2, 2018, and an additional one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter.

SEC source: 0001209191-20-005043 · doc4.xml · nonDerivative · entry 4

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 593,918

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F2 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $25.00 to $25.15 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0001209191-20-005043 · doc4.xml · nonDerivative · entry 3

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 608,385

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: 0001209191-20-005043 · doc4.xml · derivative · entry 5

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 131,134

Underlying: Common Stock · 2,200 shares

Expires 2028-07-01

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.

F3 · derivative.exercise_date: One forty-eighth (1/48th) of the shares subject to the option vested on August 2, 2018, and an additional one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter.

SEC source: 0001209191-20-005043 · doc4.xml · nonDerivative · entry 2

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 593,918

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

SEC source: 0001209191-20-005043 · doc4.xml · nonDerivative · entry 1

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 596,118

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: 0001209191-20-005034 · doc4.xml · derivative · entry 4

Paul Robert · CIK 0001757964 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 338,000

Underlying: Common Stock · 6,000 shares

Expires 2028-07-01

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.

F4 · derivative.exercise_date: One forty-eighth (1/48th) of the shares subject to the option vested on August 2, 2018, and an additional one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter.

SEC source: 0001209191-20-005034 · doc4.xml · nonDerivative · entry 3

Paul Robert · CIK 0001757964 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 273,719

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F3 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $25.21 to $25.30 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0001209191-20-005034 · doc4.xml · nonDerivative · entry 2

Paul Robert · CIK 0001757964 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 274,318

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F2 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $24.00 to $24.64 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0001209191-20-005034 · doc4.xml · nonDerivative · entry 1

Paul Robert · CIK 0001757964 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 279,719

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: 0001209191-20-004706 · doc4.xml · nonDerivative · entry 2

King Robert · CIK 0001635264 · Chief Development Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 507,317

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

SEC source: 0001209191-20-004706 · doc4.xml · nonDerivative · entry 1

King Robert · CIK 0001635264 · Chief Development Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 507,320

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F2 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $22.00 to $22.12 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0001209191-20-004048 · doc4.xml · nonDerivative · entry 1

Paul Robert · CIK 0001757964 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 273,719

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F2 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $18.25 to $19.09 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0000947871-20-000023 · ownership.xml · nonDerivative · entry 3

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 38,808

F1 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.50.

F3 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F5 · ownership.nature: The Shares are held of record by OrbiMed Partners Master Fund Limited ("OPM"). OrbiMed Capital, a registered investment adviser under the Investment Advisers Act, acts as the investment advisor to OPM. By virtue of such relationships, OrbiMed Capital may be deemed to have voting and investment power over the securities held by OPM and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-20-000023 · ownership.xml · nonDerivative · entry 2

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,558,963

F1 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.50.

F3 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F4 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL (Feeder), LP ("OrbiMed IV-AL (Feeder)"). OrbiMed GP is the general partner of OrbiMed IV-AL (Feeder). OrbiMed Advisors is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL (Feeder) and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-20-000023 · ownership.xml · nonDerivative · entry 1

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 7,992,776

F1 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.50.

F2 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL, LP ("OrbiMed IV-AL"). OrbiMed Capital GP IV LLC ("OrbiMed GP"), is the general partner of OrbiMed IV-AL. OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered adviser under the Investment Advisers Act of 1940, as amended (the "Investment Advisers Act"), is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL and as a result may be deemed to have beneficial ownership over such securities.

F3 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0001209191-20-005056 · doc4.xml · derivative · entry 1

SCHELLER RICHARD H · CIK 0001214133 · Director

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 100,000

Underlying: Common Stock · 100,000 shares

Expires 2029-12-31

F1 · derivative.exercise_date: One forty-eighth (1/48th) of the shares subject to the option shall vest on January 6, 2020, and an additional one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter, provided the Reporting Person continues to serve as a consultant under the terms of the consulting agreement between the Reporting Person and the Issuer.

SEC source: 0001209191-20-005031 · doc4.xml · derivative · entry 1

SULIMAN SHEHNAAZ · CIK 0001713070 · President and COO

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 550,000

Underlying: Common Stock · 550,000 shares

Expires 2029-12-31

F1 · derivative.exercise_date: One fourth (1/4th) of the shares subject to the option shall vest on December 9, 2020, and an additional one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 12

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 40,200

F4 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $18.60.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F8 · ownership.nature: The Shares are held of record by OrbiMed Partners Master Fund Limited ("OPM"). OrbiMed Capital, a registered investment adviser under the Investment Advisers Act, acts as the investment advisor to OPM. By virtue of such relationships, OrbiMed Capital may be deemed to have voting and investment power over the securities held by OPM and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 11

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,650,781

F4 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $18.60.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F7 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL (Feeder), LP ("OrbiMed IV-AL (Feeder)"). OrbiMed GP is the general partner of OrbiMed IV-AL (Feeder). OrbiMed Advisors is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL (Feeder) and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 10

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 8,279,563

F4 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $18.60.

F5 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL, LP ("OrbiMed IV-AL"). OrbiMed Capital GP IV LLC ("OrbiMed GP"), is the general partner of OrbiMed IV-AL. OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered adviser under the Investment Advisers Act of 1940, as amended (the "Investment Advisers Act"), is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL and as a result may be deemed to have beneficial ownership over such securities.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 9

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 41,400

F3 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.59.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F8 · ownership.nature: The Shares are held of record by OrbiMed Partners Master Fund Limited ("OPM"). OrbiMed Capital, a registered investment adviser under the Investment Advisers Act, acts as the investment advisor to OPM. By virtue of such relationships, OrbiMed Capital may be deemed to have voting and investment power over the securities held by OPM and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 8

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,653,106

F3 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.59.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F7 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL (Feeder), LP ("OrbiMed IV-AL (Feeder)"). OrbiMed GP is the general partner of OrbiMed IV-AL (Feeder). OrbiMed Advisors is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL (Feeder) and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 7

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 8,286,838

F3 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.59.

F5 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL, LP ("OrbiMed IV-AL"). OrbiMed Capital GP IV LLC ("OrbiMed GP"), is the general partner of OrbiMed IV-AL. OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered adviser under the Investment Advisers Act of 1940, as amended (the "Investment Advisers Act"), is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL and as a result may be deemed to have beneficial ownership over such securities.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 6

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 49,400

F2 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.82.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F8 · ownership.nature: The Shares are held of record by OrbiMed Partners Master Fund Limited ("OPM"). OrbiMed Capital, a registered investment adviser under the Investment Advisers Act, acts as the investment advisor to OPM. By virtue of such relationships, OrbiMed Capital may be deemed to have voting and investment power over the securities held by OPM and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 5

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,668,582

F2 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.82.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F7 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL (Feeder), LP ("OrbiMed IV-AL (Feeder)"). OrbiMed GP is the general partner of OrbiMed IV-AL (Feeder). OrbiMed Advisors is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL (Feeder) and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 4

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 8,335,162

F2 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.82.

F5 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL, LP ("OrbiMed IV-AL"). OrbiMed Capital GP IV LLC ("OrbiMed GP"), is the general partner of OrbiMed IV-AL. OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered adviser under the Investment Advisers Act of 1940, as amended (the "Investment Advisers Act"), is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL and as a result may be deemed to have beneficial ownership over such securities.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 3

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 59,800

F1 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.66.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F8 · ownership.nature: The Shares are held of record by OrbiMed Partners Master Fund Limited ("OPM"). OrbiMed Capital, a registered investment adviser under the Investment Advisers Act, acts as the investment advisor to OPM. By virtue of such relationships, OrbiMed Capital may be deemed to have voting and investment power over the securities held by OPM and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 2

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,688,932

F1 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.66.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F7 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL (Feeder), LP ("OrbiMed IV-AL (Feeder)"). OrbiMed GP is the general partner of OrbiMed IV-AL (Feeder). OrbiMed Advisors is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL (Feeder) and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-19-000992 · ownership.xml · nonDerivative · entry 1

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 8,398,697

F1 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $19.66.

F5 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL, LP ("OrbiMed IV-AL"). OrbiMed Capital GP IV LLC ("OrbiMed GP"), is the general partner of OrbiMed IV-AL. OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered adviser under the Investment Advisers Act of 1940, as amended (the "Investment Advisers Act"), is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL and as a result may be deemed to have beneficial ownership over such securities.

F6 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0000947871-19-000977 · ownership.xml · nonDerivative · entry 3

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 97,700

F1 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $18.52.

F3 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F5 · ownership.nature: The Shares are held of record by OrbiMed Partners Master Fund Limited ("OPM"). OrbiMed Capital, a registered investment adviser under the Investment Advisers Act, acts as the investment advisor to OPM. By virtue of such relationships, OrbiMed Capital may be deemed to have voting and investment power over the securities held by OPM and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-19-000977 · ownership.xml · nonDerivative · entry 2

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 2,762,811

F1 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $18.52.

F3 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

F4 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL (Feeder), LP ("OrbiMed IV-AL (Feeder)"). OrbiMed GP is the general partner of OrbiMed IV-AL (Feeder). OrbiMed Advisors is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL (Feeder) and as a result may be deemed to have beneficial ownership over such securities.

SEC source: 0000947871-19-000977 · ownership.xml · nonDerivative · entry 1

ORBIMED ADVISORS LLC · CIK 0001055951 · 10% owner

OrbiMed Capital GP IV LLC · CIK 0001502240 · 10% owner

ORBIMED CAPITAL LLC · CIK 0001157524 · 10% owner

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

10b5-1 filing: Not disclosed

Ownership: Indirect · See Footnotes

Disclosed balance after: 8,629,418

F1 · price: These shares of the Issuer's common stock ("Shares") were sold in a block order at a price of $18.52.

F2 · ownership.nature: The Shares are held of record by OrbiMed Private Investments IV-AL, LP ("OrbiMed IV-AL"). OrbiMed Capital GP IV LLC ("OrbiMed GP"), is the general partner of OrbiMed IV-AL. OrbiMed Advisors LLC ("OrbiMed Advisors"), a registered adviser under the Investment Advisers Act of 1940, as amended (the "Investment Advisers Act"), is the managing member of OrbiMed GP. By virtue of such relationships, OrbiMed GP and OrbiMed Advisors may be deemed to have voting and investment power over the securities held by OrbiMed IV-AL and as a result may be deemed to have beneficial ownership over such securities.

F3 · ownership.nature: Each of OrbiMed GP, OrbiMed Capital LLC ("OrbiMed Capital") and OrbiMed Advisors disclaims beneficial ownership of the securities reported herein for purposes of Rule 16a-1(a) under the Securities Exchange Act of 1934, as amended (the "Exchange Act"), except to the extent of its pecuniary interest therein, if any. This report on Form 4 shall not be deemed an admission that any of the Reporting Persons is a beneficial owner of such securities for the purpose of Section 16 of the Exchange Act, or for any other purpose.

SEC source: 0001209191-19-060931 · doc4.xml · nonDerivative · entry 1

Paul Robert · CIK 0001757964 · Chief Medical Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 283,719

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F2 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $19.65 to $20.31 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0001209191-19-060784 · doc4.xml · derivative · entry 3

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 133,334

Underlying: Common Stock · 6,810 shares

Expires 2028-07-01

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.

F3 · derivative.exercise_date: One forty-eighth (1/48th) of the shares subject to the option vested on August 2, 2018, and an additional one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter.

SEC source: 0001209191-19-060784 · doc4.xml · nonDerivative · entry 2

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 593,918

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F2 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $20.00 to $20.36 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0001209191-19-060784 · doc4.xml · nonDerivative · entry 1

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 600,728

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: 0001209191-19-060225 · doc4.xml · derivative · entry 3

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 140,144

Underlying: Common Stock · 500 shares

Expires 2028-07-01

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.

F3 · derivative.exercise_date: One forty-eighth (1/48th) of the shares subject to the option vested on August 2, 2018, and an additional one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter.

SEC source: 0001209191-19-060225 · doc4.xml · nonDerivative · entry 2

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 593,918

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F2 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $20.00 to $20.02 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0001209191-19-060225 · doc4.xml · nonDerivative · entry 1

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 594,418

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: 0001209191-19-059767 · doc4.xml · derivative · entry 9

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 140,644

Underlying: Common Stock · 2,300 shares

Expires 2028-07-01

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.

F5 · derivative.exercise_date: One forty-eighth (1/48th) of the shares subject to the option vested on August 2, 2018, and an additional one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter.

SEC source: 0001209191-19-059767 · doc4.xml · nonDerivative · entry 6

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 593,918

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F4 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $20.00 to $20.24 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0001209191-19-059767 · doc4.xml · nonDerivative · entry 5

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 596,218

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: 0001209191-19-059767 · doc4.xml · derivative · entry 8

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 142,944

Underlying: Common Stock · 5,156 shares

Expires 2028-07-01

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.

F5 · derivative.exercise_date: One forty-eighth (1/48th) of the shares subject to the option vested on August 2, 2018, and an additional one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter.

SEC source: 0001209191-19-059767 · doc4.xml · nonDerivative · entry 4

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 593,918

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F3 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $20.00 to $20.09 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0001209191-19-059767 · doc4.xml · nonDerivative · entry 3

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 599,074

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: 0001209191-19-059767 · doc4.xml · derivative · entry 7

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 148,100

Underlying: Common Stock · 1,500 shares

Expires 2028-07-01

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.

F5 · derivative.exercise_date: One forty-eighth (1/48th) of the shares subject to the option vested on August 2, 2018, and an additional one forty-eighth (1/48th) of the shares subject to the option shall vest each month thereafter.

SEC source: 0001209191-19-059767 · doc4.xml · nonDerivative · entry 2

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 593,918

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan.

F2 · price: The sale price reported in column 4 of Table I represents the weighted average sale price of the shares purchased ranging from $20.00 to $20.005 per share. Upon request by the Commission staff, the Issuer, or a security holder of the Issuer, the Reporting Person will provide full information regarding the number of shares sold at each separate price.

SEC source: 0001209191-19-059767 · doc4.xml · nonDerivative · entry 1

Oney Sabah · CIK 0001757776 · Chief Business Officer

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 595,418

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: 0001209191-19-059299 · doc4.xml · nonDerivative · entry 1

Yu Calvin · CIK 0001757799 · Vice President, Finance

10b5-1 filing: Not disclosed

Ownership: Direct

Disclosed balance after: 175,294

F1 · kind: The sales reported by the Reporting Person were effected pursuant to a Rule 10b5-1 trading plan. Consists of 1,315 shares acquired on November 29, 2019 at a price of $15.844 per share under the Issuer's 2019 Employee Stock Purchase Plan.