{"transactions":[{"id":2414055,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2022-02-03T21:18:28.000Z","date":"2022-02-01","kind":"grant","acquired":true,"shares":53190,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F3","text":"The shares underlying this option vest as to 25% on February 1, 2023, with the remainder vesting in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date."}],"balance_after":53190,"derivative":{"exercise_price":11.18,"expiration_date":"2032-02-01","underlying":"Common Stock","underlying_shares":53190},"source":{"system":"sec-edgar","filing":"0000899243-22-004592","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924322004592/doc4.xml","form_type":"4"}},{"id":2414054,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2022-02-03T21:18:28.000Z","date":"2022-02-01","kind":"grant","acquired":true,"shares":38014,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Consists of restricted stock units (\"RSUs\"). Each RSU represents the right to receive one share of common stock upon vesting. The RSUs vest in four equal annual installments beginning on February 1, 2023, subject to the Reporting Person's continued service through the applicable vesting date."},{"field":"balance_after","element":"sharesOwnedFollowingTransaction","label":"F2","text":"Includes 1,500 shares of common stock and 62,081 RSUs held by the Reporting Person."}],"balance_after":63581,"source":{"system":"sec-edgar","filing":"0000899243-22-004592","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924322004592/doc4.xml","form_type":"4"}},{"id":2586625,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2021-08-30T20:15:30.000Z","date":"2021-08-26","kind":"grant","acquired":true,"shares":24067,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Consists of restricted stock units (\"RSUs\"). Each RSU represents the right to receive one share of common stock upon vesting. The RSUs vest in four equal annual installments beginning on August 26, 2022, subject to the Reporting Person's continued service through the applicable vesting date."}],"balance_after":25567,"source":{"system":"sec-edgar","filing":"0000899243-21-034501","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924321034501/doc4.xml","form_type":"4"}},{"id":2881984,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2021-02-04T00:47:22.000Z","date":"2021-02-01","kind":"grant","acquired":true,"shares":57432,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The shares underlying this option vest as to 25% on February 1, 2022, with the remainder vesting in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date."}],"balance_after":57432,"derivative":{"exercise_price":19.18,"expiration_date":"2031-02-01","underlying":"Common Stock","underlying_shares":57432},"source":{"system":"sec-edgar","filing":"0000899243-21-004786","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924321004786/doc4.xml","form_type":"4"}},{"id":2938035,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2020-12-18T21:15:08.000Z","date":"2020-12-16","kind":"exercise","acquired":false,"shares":12000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"All shares underlying this option were fully vested as of March 7, 2020."}],"balance_after":8434,"derivative":{"exercise_price":5.9,"expiration_date":"2027-07-05","underlying":"Common Stock","underlying_shares":12000},"source":{"system":"sec-edgar","filing":"0000899243-20-034477","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924320034477/doc4.xml","form_type":"4"}},{"id":2938034,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2020-12-18T21:15:08.000Z","date":"2020-12-16","kind":"sale","acquired":false,"shares":12000,"price":19,"value":228000.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"All transactions reported on this Form 4 were made pursuant to a previously adopted Rule 10b5-1 trading plan. Specifically, the transactions reported herein relate to option exercises and related sales (totaling 12,000 shares)."}],"balance_after":1500,"source":{"system":"sec-edgar","filing":"0000899243-20-034477","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924320034477/doc4.xml","form_type":"4"}},{"id":2938033,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2020-12-18T21:15:08.000Z","date":"2020-12-16","kind":"exercise","acquired":true,"shares":12000,"price":5.9,"value":70800.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"All transactions reported on this Form 4 were made pursuant to a previously adopted Rule 10b5-1 trading plan. Specifically, the transactions reported herein relate to option exercises and related sales (totaling 12,000 shares)."}],"balance_after":13500,"source":{"system":"sec-edgar","filing":"0000899243-20-034477","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924320034477/doc4.xml","form_type":"4"}},{"id":3294971,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2020-02-03T22:32:41.000Z","date":"2020-02-03","kind":"grant","acquired":true,"shares":55000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The shares underlying this option vest as to 25% on February 3, 2021, with the remainder vesting in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date."}],"balance_after":55000,"derivative":{"exercise_price":9.34,"expiration_date":"2030-02-03","underlying":"Common Stock","underlying_shares":55000},"source":{"system":"sec-edgar","filing":"0000899243-20-002616","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924320002616/doc4.xml","form_type":"4"}},{"id":3713461,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2019-01-03T00:18:00.000Z","date":"2019-01-02","kind":"grant","acquired":true,"shares":65000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The shares underlying this option vest as to 25% on January 2, 2020, with the remainder vesting in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date."}],"balance_after":65000,"derivative":{"exercise_price":6.26,"expiration_date":"2029-01-02","underlying":"Common Stock","underlying_shares":65000},"source":{"system":"sec-edgar","filing":"0000899243-19-000179","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924319000179/doc4.xml","form_type":"4"}},{"id":3871861,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2018-07-07T01:45:24.000Z","date":"2018-07-05","kind":"exercise","acquired":false,"shares":4000,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F2","text":"The shares underlying this option vested as to 25% on March 7, 2017, with the remainder vesting in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date."}],"balance_after":20434,"derivative":{"exercise_price":5.9,"expiration_date":"2027-07-05","underlying":"Common Stock","underlying_shares":4000},"source":{"system":"sec-edgar","filing":"0000899243-18-019568","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":3,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924318019568/doc4.xml","form_type":"4"}},{"id":3871860,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2018-07-07T01:45:24.000Z","date":"2018-07-05","kind":"sale","acquired":false,"shares":4000,"price":17.5,"value":70000.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The option exercises and related sales reported in this Form 4 were made pursuant to a Rule 10b5-1 trading plan previously entered into by the Reporting Person in December 2017."}],"balance_after":1500,"source":{"system":"sec-edgar","filing":"0000899243-18-019568","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":2,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924318019568/doc4.xml","form_type":"4"}},{"id":3871859,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2018-07-07T01:45:24.000Z","date":"2018-07-05","kind":"exercise","acquired":true,"shares":4000,"price":5.9,"value":23600.0,"ownership":{"direct":true},"footnotes":[{"field":"kind","element":"transactionCoding","label":"F1","text":"The option exercises and related sales reported in this Form 4 were made pursuant to a Rule 10b5-1 trading plan previously entered into by the Reporting Person in December 2017."}],"balance_after":5500,"source":{"system":"sec-edgar","filing":"0000899243-18-019568","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924318019568/doc4.xml","form_type":"4"}},{"id":4130423,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Stock Option (Right to Buy)","published_at":"2017-12-15T21:07:52.000Z","date":"2017-12-13","kind":"grant","acquired":true,"shares":62540,"price":0,"value":0.0,"ownership":{"direct":true},"footnotes":[{"field":"derivative.exercise_date","element":"exerciseDate","label":"F1","text":"The shares underlying this option vest as to 25% on December 13, 2018, with the remainder vesting in 36 equal monthly installments thereafter, subject to the Reporting Person's continued service through the applicable vesting date."}],"balance_after":62540,"derivative":{"exercise_price":11.63,"expiration_date":"2027-12-12","underlying":"Common Stock","underlying_shares":62540},"source":{"system":"sec-edgar","filing":"0000899243-17-028851","document":"doc4.xml","document_sequence":1,"table":"derivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924317028851/doc4.xml","form_type":"4"}},{"id":4170242,"issuer":{"id":7014,"kind":"organization","name":"Spero Therapeutics, Inc."},"owners":[{"id":130816,"kind":"person","name":"Larkin Cristina","position":1,"cik":"0001721173","reported_name":"Larkin Cristina","relationship":{"director":false,"officer":true,"ten_percent_owner":false,"other":false,"officer_title":"Chief Operating Officer"}}],"security":"Common Stock","published_at":"2017-11-07T21:05:30.000Z","date":"2017-11-06","kind":"purchase","acquired":true,"shares":1500,"price":14,"value":21000.0,"ownership":{"direct":true},"footnotes":[{"field":"shares","element":"transactionShares","label":"F1","text":"Reflects shares that were purchased through a directed share program in connection with the Issuer's initial public offering."}],"balance_after":1500,"source":{"system":"sec-edgar","filing":"0000899243-17-025506","document":"doc4.xml","document_sequence":1,"table":"nonDerivative","row_type":"transaction","position":1,"url":"https://www.sec.gov/Archives/edgar/data/1701108/000089924317025506/doc4.xml","form_type":"4"}}]}