Protalix Announces Exchange and Discharge of Remaining 2018 Notes

Exchange and Discharge of Remaining 2018 Notes

CARMIEL, Israel, May 24, 2018 -- GlobeNewswire

/Protalix BioTherapeutics, Inc. (the "Company") (NYSE American: PLX) (TASE:PLX) announced today that $3.42 million

of the aggregate principal amount of the Company's outstanding 4.5% Convertible Senior Notes due 2018 (the "Notes")

will be exchanged for 2,613,636 shares of the Company's common stock and $2.27 million in cash. Additionally, the Company

announced today that it has delivered the necessary funds under the indenture governing the Notes to effectively discharge the

remaining outstanding Notes. Additional details regarding the exchange can be found in the Company's Form 8-K to be filed

with the Securities and Exchange Commission.

BioTherapeutics, Inc.

Protalix is a biopharmaceutical

company focused on the development and commercialization of recombinant therapeutic proteins expressed through its proprietary

plant cell-based expression system, ProCellEx . Protalix's unique expression system presents a proprietary

method for developing recombinant proteins in a cost-effective, industrial-scale manner. Protalix's first product manufactured

by ProCellEx, taliglucerase alfa, was approved for marketing by the U.S. Food and Drug Administration (FDA) in May 2012 and,

subsequently, by the regulatory authorities of other countries. Protalix has licensed to Pfizer Inc. the worldwide development

and commercialization rights for taliglucerase alfa, excluding Brazil, where Protalix retains full rights. Protalix's

development pipeline includes the following product candidates: pegunigalsidase alfa, a modified version of the recombinant human

alpha-GAL-A protein for the treatment of Fabry disease; OPRX-106, an orally-delivered anti-inflammatory treatment; alidornase alfa

for the treatment of Cystic Fibrosis; and others. Protalix has entered into an ex-United States partnership with Chiesi Farmaceutici

S.p.A. for the development and commercialization of pegunigalsidase alfa. Protalix maintains full rights to pegunigalsidase

alfa in the United States.

To the extent that statements

in this press release are not strictly historical, all such statements are forward-looking, and are made pursuant to the safe-harbor

provisions of the Private Securities Litigation Reform Act of 1995. The terms "expect," "anticipate, "believe,"

"estimate," "project," "plan," "should" and "intend" and other words

or phrases of similar import are intended to identify forward-looking statements. These forward-looking statements are subject

to known and unknown risks and uncertainties that may cause actual future experience and results to differ materially from the

statements made. These statements are based on our current beliefs and expectations as to such future outcomes. Drug

discovery and development involve a high degree of risk. Factors that might cause material differences include, among others:

failure or delay in the commencement or completion of our preclinical and clinical trials which may be caused by several factors,

including: slower than expected rates of patient recruitment; unforeseen safety issues; determination of dosing issues; lack of

effectiveness during clinical trials; inability to monitor patients adequately during or after treatment; inability or unwillingness

of medical investigators and institutional review boards to follow our clinical protocols; and lack of sufficient funding to finance

clinical trials; the risk that the results of the clinical trials of our product candidates will not support our claims of superiority,

safety or efficacy, that our product candidates will not have the desired effects or will be associated with undesirable side effects

or other unexpected characteristics; risks related to the ultimate purchase by Funda o Oswaldo Cruz of

alfataliglicerase pursuant to the stated purchase intentions of the Brazilian Ministry of Health of the stated amounts,

if at all; risks related to the successful conclusion of our negotiations with the Brazilian Ministry of Health regarding

the purchase of alfataliglicerase generally; risks related to our commercialization efforts for alfataliglicerase in Brazil;

risks relating to the compliance by Funda o Oswaldo Cruz with its purchase obligations and related milestones

under our supply and technology transfer agreement; risks related to the amount and sufficiency of our cash and cash equivalents;

risks related to the amount of our future revenues, operations and expenditures; risks related to our ability to maintain and manage

our relationship with Chiesi Farmaceutici and any other collaborator, distributor or partner; the risk that despite the FDA's

grant of fast track designation for pegunigalsidase alfa for the treatment of Fabry disease, we may not experience a faster development

process, review or approval compared to applications considered for approval under conventional FDA procedures; risks related to

the FDA's ability to withdraw the fast track designation at any time; risks relating to our ability to make scheduled payments

of the principal of, to pay interest on or to refinance our outstanding notes or any other indebtedness; our dependence on performance

by third party providers of services and supplies, including without limitation, clinical trial services; our ability to identify

suitable product candidates and to complete preclinical studies of such product candidates; the inherent risks and uncertainties

in developing drug platforms and products of the type we are developing; the impact of development of competing therapies and/or

technologies by other companies and institutions; potential product liability risks, and risks of securing adequate levels of product

liability and other necessary insurance coverage; and other factors described in our filings with the U.S. Securities and

Exchange Commission. The statements in this press release are valid only as of the date hereof and we disclaim any obligation

to update this information, except as may be required by law.

Source: Protalix BioTherapeutics,