Summit Therapeutics plc 
(‘Summit’ or the ’Company’)

Exercise of Restricted Stock Units

Oxford, UK, and Cambridge, MA, US, 24 December 2019 – Summit Therapeutics plc (NASDAQ: SMMT, AIM: SUMM) announces the exercise by Leopoldo Zambeletti, a Non-Executive Director of Summit, of restricted stock units (‘RSUs’) that entitled the holder to subscribe for an ordinary share of one penny nominal value at a subscription price of one penny per ordinary share. 

The RSUs were granted under the Company’s 2017 Remuneration Policy and were eligible for exercise for a limited time after completion of a vesting period of one year. Details of the exercise of the RSUs, all of which took place on 23 December 2019, and which have been duly notified to the Company, are summarised below.

Director	Position	RSU’s Exercised	Shareholding (ordinary shares)	% of Issued Share Capital
Leopoldo Zambeletti	Non-Executive Director	17,073	33,052	0.02%

Application has been made to the London Stock Exchange for the admission of 17,073 ordinary shares to trading on AIM and it is expected that admission will become effective and that dealings will commence at 8.00 a.m. on or around 31 December 2019.

About Summit Therapeutics
Summit Therapeutics is a leader in antibiotic innovation. Our new mechanism antibiotics are designed to become the new standards of care for the benefit of patients and create value for payors and healthcare providers. We are currently developing new mechanism antibiotics for infections caused by C. difficile, N. gonorrhoeae and ESKAPE pathogens and are using our proprietary Discuva Platform to expand our pipeline. For more information, visit www.summitplc.com and follow us on Twitter @summitplc.

Contacts

Summit
Richard Pye (UK office)	Tel:	+44 (0)1235 443 951
Michelle Avery (US office)		+1 617 225 4455
Cairn Financial Advisers LLP (Nominated Adviser)	Tel:	+44 (0)20 7213 0880
Liam Murray / Tony Rawlinson

Notification of Transactions pursuant to Article 19(1) of Regulation (EU) No. 596/2014

1	Details of the persons discharging managerial responsibilities/person closely associated
a)	Name	(i)  Leopoldo Zambeletti
2	Reason for the notification
a)	Position / status	(i)  Non-Executive Director
b)	Initial notification / Amendment	Initial notification
3	Details of the issuer, emission allowance market participant, auction platform, auctioneer or auction monitor
a)	Name	Summit Therapeutics plc
b)	LEI	213800NRW8AOMYMTBD89
4	Details of the transaction(s): section to be repeated for (i) each type of instrument; (ii) each type of transaction; (iii) each date; and (iv) each place where transactions have been conducted
a)	Description of the financial instrument, type of instrument	Ordinary shares of 1 penny each
	Identification code	GB00BN40HZ01
b)	Nature of the transactions	Exercise of restricted stock units (RSUs) to subscribe for ordinary shares of one penny nominal value
c)	Price(s) and volume(s)		Price(s)	Volume(s)
			(i) 1p (exercise price)	(i)  17,073
d)	Aggregated information   – Aggregated volume   – Price	17,073 ordinary shares   1 penny (exercise price)
e)	Date of the transactions	23 December 2019
f)	Place of the transactions	Outside a trading venue

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