Security	Conv. / exercise price	Date	Code	Shares	A/D	Exercisable	Expires	Underlying	Underlying shares	Owned after	D/I
Senior Secured Convertible Note due 2024 (PIK Interest)^F1,F3,F2	$0.40	Sep 30, 2018	A	—	A	—	Jan 15, 2024	Common Stock	314,894	—	I
Senior Secured Convertible Note due 2024 (PIK Interest)^F1,F4,F2	$0.40	Sep 30, 2018	A	—	A	—	Jan 15, 2024	Common Stock	361,135	—	I

Explanation of responses

F1On September 30, 2018 the 2014 Notes held by HCP Fund and Hybrid Fund accrued interest which is payable in kind ("PIK Interest") in the form of additional principal. Excludes PIK interest on notes issued to certain reporting persons and other investors on February 17, 2015, February 23, 2018, and July 13, 2018, reporting of which is exempt pursuant to Rule 16a-9.
F2Immediately exercisable.
F3HealthCor Partners Fund, L.P. ("HCP Fund") is a private investment partnership which is the direct beneficial owner of the securities reported herein. HealthCor Partners L.P. serves as its general partner and HealthCor Partners GP, LLC ("HCPGP") serves as the general partner of HealthCor Partners L.P. HealthCor Partners Management, L.P. serves as the investment manager to HCP Fund and HealthCor Partners Management GP, LLC ("HCPMGP") serves as the general partner to HealthCor Partners Management, L.P. Jeffrey C. Lightcap, Arthur Cohen and Joseph Healey are managing members of HCPMGP and HCPGP. Each person disclaims beneficial ownership of any securities that exceed their pecuniary interest in the securities held by these entities. Mr. Lightcap was appointed a director of the issuer in connection with the initial investment.
F4HealthCor Hybrid Offshore Master Fund, L.P. ("Hybrid Fund") is a private investment partnership which is the direct beneficial owner of the securities reported herein. HealthCor Hybrid Offshore GP, LLC ("Offshore GP") serves as its general partner and HealthCor Group, LLC ("Group") serves as the general partner of Offshore GP. HealthCor Management, L.P. serves as the investment manager to Hybrid Fund and HealthCor Associates, LLC ("Associates") serves as the general partner to HealthCor Management, L.P. Arthur Cohen and Joseph Healey are managing members of Associates and Group. Each reporting person disclaims beneficial ownership of any securities that exceed their pecuniary interest in the securities held by these entities.

Remarks

HealthCor Management, L.P. is the designated filer on behalf of the reporting persons listed on Exhibit 99.1, attached hereto. Due to the number of reporting persons, this is one of two Form 4's filed relating to the same securities.