Protalix BioTherapeutics and Chiesi Farmaceutici Announce Successful pre-BLA Meeting with FDA for Accelerated Approval of pegunigalsidase alfa for the Treatment of Fabry Disease in the United States FDA indicated that ex

Protalix BioTherapeutics and Chiesi Farmaceutici

Announce Successful pre-BLA Meeting with FDA for Accelerated Approval of

pegunigalsidase alfa for the Treatment of Fabry Disease in the United States

FDA indicated that existing clinical

data, nonclinical data, safety database and manufacturing data will support a Biologics License Application submission

No additional clinical trials are necessary

for BLA submission, expected by April of 2020

CARMIEL, Israel, November 18,

2019 -- Protalix BioTherapeutics, Inc. (NYSE American: PLX) (TASE: PLX), a biopharmaceutical company focused on

the development, production and commercialization of recombinant therapeutic proteins produced by its proprietary ProCellEx

plant cell-based protein expression system, and its development and commercialization partner, Chiesi Farmaceutici S.p.A., an international

research-focused healthcare Group (Chiesi), today announced that they have completed a successful Type B Pre-Biologics License

Application (BLA) meeting with the U.S. Food and Drug Administration (FDA) regarding the Accelerated Approval pathway for

pegunigalsidase alfa (PRX-102) for the treatment of Fabry disease.

The Company, together with Chiesi, met with the FDA on October

15 to discuss key information on pegunigalsidase alfa to be included in a proposed BLA filing under the Accelerated Approval pathway.

The Company and Chiesi report that they have reached alignment with the FDA on the Accelerated Approval pathway for pegunigalsidase

alfa. The BLA, as expected to be submitted to the FDA, will include data from the Company's completed phase I/II clinical

trials of pegunigalsidase alfa and from its ongoing phase III BRIDGE clinical trial.

"The confirmation by the FDA regarding the proposed BLA

submission, together with the finalization of the BALANCE study enrollment (78 patients) and the very promising interim results

from the BRIDGE study, are three recent significant consecutive milestones achieved with respect to our Fabry late-stage clinical

program," said Dror Bashan, Protalix's President and Chief Executive Officer. "We are committed to the completion

of this program with positive results for the benefit of the Fabry patient community."

The Company and Chiesi also announced that they have reached

an agreement with the FDA regarding the ongoing BALANCE study, as currently designed, serving as the confirmatory trial for PRX-102.

A confirmatory trial is required to convert a BLA approved under Accelerated Approval into a traditional approval.

The Company and Chiesi expect to submit the BLA to the FDA by

April of 2020. The FDA indicated that the nonclinical data, the clinical data, the safety database and manufacturing data are sufficient

to support the BLA submission, and that no additional clinical trials will be required for the proposed BLA submission. The Company

and Chiesi expect that the fully electronic BLA submission will include a comprehensive set of preclinical, clinical and manufacturing

related information on pegunigalsidase alfa. If approved, the Company will be eligible to receive a milestone payment from Chiesi.

"We have now had three successful interactions with the

FDA during 2019, which built on our long-term relationship with the Agency and made our regulatory path forward for pegunigalsidase

alfa clear," said Dr. Einat Almon, Protalix's Senior Vice President, Product Development. "We expect that alignment

with the FDA on the Accelerated Approval pathway for pegunigalsidase alfa results in our being significantly closer to bringing

an approved product to market to help Fabry patients. Together with our partner Chiesi, we look forward to completing the application

process, as well as continuing with our double blind head-to-head phase III BALANCE clinical trial, which we feel will further

strengthen the position of pegunigalsidase alfa within the Fabry patient community."

Fabry disease is an X-linked inherited disease that results

from deficient activity of the lysosomal enzyme alpha galactosidase A resulting in progressive accumulation of abnormal deposits

of a fatty substance called globotriaosylceramide (Gb3) in blood vessel walls throughout a person's body. Fabry

disease occurs in one person per 40,000. Fabry patients inherit a deficiency of the enzyme alpha-galactosidase-A, which is normally

responsible for the breakdown of Gb3. The abnormal storage of Gb3 increases with time and, accordingly, Gb3

accumulates, primarily in the blood and in the blood vessel walls. The ultimate consequences of Gb3 deposition range

from episodes of pain and impaired peripheral sensation to end-organ failure - particularly of the kidneys, but also of the

heart and the cerebrovascular system.

About pegunigalsidase alfa (PRX-102)

The Company's proprietary pegunigalsidase

alfa is an investigational, plant cell culture expressed, and chemically modified stabilized version of, the recombinant alpha-Galactosidase-A

enzyme. Protein sub-units are covalently bound via chemical cross-linking using short PEG moieties, resulting in a molecule with

unique pharmacokinetic parameters. In clinical studies, pegunigalsidase alfa has been observed to have a circulatory half-life

of approximately 80 hours. The Company designed pegunigalsidase alfa to potentially address the continued unmet clinical need in

Fabry patients of continuous disease progression, infusion reactions and immunogenicity.

About the Chiesi Group

Based in Parma, Italy, Chiesi Farmaceutici is an international research-oriented group with over 80 years' experience

in the pharmaceutical sector and is present in 28 countries. The Group researches, develops and commercializes innovative medicines

in respiratory disease, special care and rare disease therapeutic areas. The Group's Research & Development center is

integrated with six other important research and development groups in France, the USA, the UK and Sweden, to promote its pre-clinical,

clinical and registration programs. The Group employs around 5,700 people. Chiesi Group is a certified B Corp. For more information,

please visit www.chiesi.com.

About Protalix BioTherapeutics,

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 was the first company to gain FDA

approval of a protein produced through a plant cell-based, in suspension expression system. Protalix's unique expression

system represents a new method for developing recombinant proteins in an industrial-scale manner. Protalix's pipeline consists

of proprietary, potentially clinically superior versions of recombinant therapeutic proteins that target established pharmaceutical

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, in phase III clinical trials (BALANCE, BRIDGE and BRIGHT studies); OPRX-106, an orally delivered

anti-inflammatory treatment, and alidornase alfa, both in phase II clinical trials. Protalix has partnered with Chiesi Farmaceutici

S.p.A., both in the United States and outside the United States, for the development and commercialization of pegunigalsidase alfa.

Forward-Looking Statements

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 and the final results of a clinical trial may be different than the preliminary findings

for the clinical trial. Factors that might cause material differences include, among others: risks related to our ability to identify

and complete strategic alternatives on attractive terms or at all within the time period required to regain compliance with the

continued listing standards of the NYSE American; risks related to our ability to continue as a going concern absent a refinancing

or restructuring; risks related to any transactions we may effect in the public or private equity markets to raise capital to finance

future research and development activities, general and administrative expenses and working capital; failure or delay in the commencement

or completion of our preclinical and clinical trials which may be caused by several factors, including: risks that the FDA will

not accept an application for accelerated approval of PRX-102 with the data generated to date or will request additional data or

other conditions of our submission of any application for accelerated approval of PRX-102; 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; and inability or unwillingness of medical investigators and institutional

review boards to follow our clinical protocols; the risk that the results of the clinical trials of our product candidates will

not support our claims of 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 our ability to maintain and manage our relationship

with Chiesi Farmaceutici and any other collaborator, distributor or partner; 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