On June 15, 2021, PRA Health Sciences, Inc. (“PRA”)
held a special meeting of its stockholders (the “Special Meeting”). At the Special Meeting, based on preliminary voting results,
PRA’s stockholders voted to (a) adopt the Agreement and Plan of Merger, dated as of February 24, 2021 (as it may be amended from
time to time, the “Merger Agreement”), by and among PRA, ICON plc (“ICON”), ICON US Holdings Inc., a wholly owned
subsidiary of ICON (“US HoldCo”), and Indigo Merger Sub, Inc., a wholly owned subsidiary of ICON and US HoldCo (the “PRA
Merger Agreement Proposal”), (b) approve, on an advisory (non-binding) basis, the executive officer compensation that will or may
be paid to PRA’s named executive officers that is based on or otherwise relates to the transactions contemplated by the Merger Agreement,
and (c) approve the adjournment of the Special Meeting to solicit additional proxies if there are not sufficient votes at the time of
the Special Meeting to approve the PRA Merger Agreement Proposal or to ensure that any supplement or amendment to the joint proxy statement/prospectus
is timely provided to PRA stockholders.
Based on the results of the Special Meeting, subject
to the satisfaction or waiver of the remaining closing conditions under the Merger Agreement, the transactions contemplated by the Merger
Agreement are expected to be consummated on July 1, 2020.
Cautionary Note Regarding Forward-Looking Statements
This communication contains forward-looking statements
within the meaning of the Private Securities Litigation Reform Act of 1995, Section 27A of the Securities Act of 1933, as amended, and
Section 21E of the Securities Exchange Act of 1934, as amended. These forward-looking statements generally include statements regarding
the potential transaction between ICON and PRA, including any statements regarding the expected timetable for completing the potential
transaction, the ability to complete the potential transaction, the expected benefits of the potential transaction (including anticipated
synergies, projected financial information and future opportunities) and any other statements regarding ICON’s and PRA’s future
expectations, beliefs, plans, objectives, results of operations, financial condition and cash flows, or future events or performance.
These statements are often, but not always, made through the use of words or phrases such as “anticipate,” “intend,”
“plan,” “believe,” “project,” “estimate,” “expect,” “may,” “should,”
“will” and similar expressions. All such forward-looking statements are based on current expectations of ICON’s and
PRA’s management and therefore involve estimates and assumptions that are subject to risks, uncertainties and other factors that
could cause actual results to differ materially from the results expressed in the statements. Key factors that could cause actual results
to differ materially from those projected in the forward-looking statements include uncertainties as to the timing to consummate the potential
transaction; the risk that a condition to closing the potential transaction may not be satisfied; litigation relating to the potential
transaction that has been or could be instituted against ICON, PRA or their respective directors; the effects of disruption to ICON’s
or PRA’s respective businesses; restrictions during the pendency of the potential transaction that may impact ICON’s or PRA’s
ability to pursue certain business opportunities or strategic transactions; the effect of this communication on ICON’s or PRA’s
stock prices; transaction costs; ICON’s ability to achieve the benefits from the proposed transaction; ICON’s ability to effectively
integrate acquired operations into its own operations; the ability of ICON or PRA to retain and hire key personnel; unknown liabilities;
and the diversion of management time on transaction-related issues. Other important factors that could cause actual results to differ
materially from those in the forward-looking statements include the effects of industry, market, economic, political or regulatory conditions
outside of ICON’s or PRA’s control (including public health crises, such as pandemics and epidemics); risks regarding PRA’s
ability to maintain large customer contracts or enter into new contracts; PRA’s ability to attract suitable investigators and patients
for its clinical trials; PRA’s ability to keep pace with rapid technological change; PRA’s potential liability if a patient
is harmed; and the factors set forth under the heading “Risk Factors” of ICON’s Annual Report on Form 20-F and PRA’s
Annual Report on Form 10-K and most recent Quarterly Report on Form 10-Q, and in subsequent filings with the U.S. Securities and Exchange
Commission (the “SEC”). These risks, as well as other risks associated with the potential transaction, are more fully discussed
in the joint proxy statement/prospectus filed with the SEC in connection with the proposed transaction. Other unpredictable or unknown
factors not discussed in this communication could also have material adverse effects on forward-looking statements. Neither ICON nor PRA
assumes any obligation to update any forward-looking statements, except as required by law. Readers are cautioned not to place undue reliance
on these forward-looking statements that speak only as of the date hereof.