SUPPLEMENT TO DEFINITIVE PROXY STATEMENT
This supplement (this Supplement) to the Definitive Proxy Statement on Schedule 14A filed on April 7, 2021 (the
Definitive Proxy Statement), by MannKind Corporation, a Delaware corporation (the Company), is being filed to supplement the Definitive Proxy Statement as described below.
DELINQUENT SECTION 16(A) REPORTS
Certain filings required by Section 16(a) of the Exchange Act of 1934, as amended, to be made by certain of the Companys directors
and executive officers in 2020 were filed late. Specifically, one Form 4 filing for each of Jennifer Grancio and Sabrina Kay, in connection with equity awards granted to each of the aforementioned directors on March 23, 2020 and
December 1, 2020, respectively, was filed late. In addition, a Form 3 filing for Alejandro Galindo, who joined the Company as an executive officer on August 4, 2020, was filed late. These late filings were due to a delay in obtaining EDGAR
filer codes for these individuals following their appointment to their respective roles.
In addition, one Form 4 filing for each of
Michael Castagna, Steven B. Binder, Rosabel R. Alinaya, David Thomson, Joseph Kocinsky, Stuart A. Tross and Patrick McCauley was filed late. These filings related to options granted in 2016 and 2017 that vest upon the achievement of certain defined
performance milestones. On February 25, 2020, one of the defined performance milestones was met, resulting in the partial vesting of such options. The filings were received by the EDGAR filing system the morning after the filing deadline due to
an administrative delay in submitting the filings to the system.
Except as specifically revised by the information contained herein, this
Supplement does not modify, amend or otherwise affect any of the other information set forth in the Definitive Proxy Statement. This Supplement should be read with the Definitive Proxy Statement, and, from and after the date of this Supplement, any
references to the Definitive Proxy Statement will be deemed to include the Definitive Proxy Statement as supplemented hereby.