Prothena Corporation plc
May 5, 2015

Prothena Reports First Quarter 2015 Financial Results and Provides R&D Update

DUBLIN, Ireland, May 5, 2015 (GLOBE NEWSWIRE) -- Prothena Corporation plc (Nasdaq:PRTA), a late-stage clinical biotechnology company focused on the discovery, development and commercialization of novel protein immunotherapy programs, today reported financial results for the first quarter ended March 31, 2015 and provided an update on its lead programs.

"During the first quarter, we reported positive Phase 1 data confirming that PRX002 was safe and well tolerated, and importantly, that a single dose of PRX002 resulted in robust, rapid and dose-dependent mean reduction of free serum alpha-synuclein of up to 96%. Reducing alpha-synuclein may translate into a delay or reversal of disease progression in patients with Parkinson's disease," said Dale Schenk, PhD, President and Chief Executive Officer of Prothena. "Taken in combination with the Phase 1/2 results for NEOD001 that drove the initiation of The VITAL Amyloidosis Study, our global Phase 3 registrational trial, today we have a multi-product pipeline of potentially disease-modifying immunotherapies."

Dr. Schenk continued, "Further, PRX003 is expected to enter the clinic in the first half of this year, and we believe we are exceptionally well capitalized for sustainable development growth and for becoming a commercial company in the years ahead."

First Quarter 2015 and Recent Highlights

Upcoming Research and Development Pipeline Milestones

Prothena's research and development pipeline includes three lead protein immunotherapy programs.

NEOD001 is a monoclonal antibody for the potential treatment of AL amyloidosis:

PRX002 is a monoclonal antibody for the potential treatment of Parkinson's disease and other related synucleinopathies, and is the primary focus of Prothena's worldwide collaboration with Roche:

PRX003 is a monoclonal antibody for the potential treatment of psoriasis and other inflammatory diseases:

First Quarter 2015 Financial Results and Guidance

Prothena reported a net loss of $15.2 million for the first quarter of 2015 as compared to net income of $17.9 million for the first quarter of 2014. Net loss per share was $0.55 for the first quarter of 2015 as compared to net income per share of $0.78 on a fully diluted basis for the first quarter of 2014.

Prothena reported total revenue of $0.6 million for the first quarter of 2015 as compared to total revenue of $32.2 million for the first quarter of 2014. The decrease was primarily due to $32.1 million in collaboration revenue recognized in relation to the PRX002 collaboration with Roche in the first quarter of 2014 compared to $0.6 million in collaboration revenue recognized in the first quarter of 2015.

Research and development (R&D) expenses totaled $10.6 million for the first quarter of 2015 as compared to $9.3 million for the first quarter of 2014. The increase in R&D expenses was primarily due to increased external expenses related to clinical trials, and higher personnel costs offset by lower external product manufacturing expenses and higher net expense reimbursements from Roche. R&D expenses included non-cash share-based compensation expense of $0.8 million for the first quarter of 2015 as compared to $0.5 million for the first quarter of 2014.

General and administrative (G&A) expenses totaled $5.0 million for the first quarter of 2015 as compared to $4.9 million for first quarter of 2014. The increase in G&A expenses was primarily due to increases in personnel costs. G&A expenses included non-cash share-based compensation expense of $0.9 million in both the first quarter of 2015 and the first quarter of 2014.

Total non-cash share-based compensation expense was $1.7 million for the first quarter of 2015 as compared to $1.3 million for the first quarter of 2014.

As of March 31, 2015, Prothena had $279.9 million in cash and cash equivalents and no outstanding debt. In April 2015, Prothena raised net proceeds of $131.4 million through a public offering of 3.8 million ordinary shares. After completion of that offering and as of April 24, 2015, Prothena had 31.3 million ordinary shares outstanding.

The Company expects the full year 2015 net cash burn from operating and investing activities to be $66 to $72 million, ending the year with approximately $356 million in cash (mid-point). The estimated full year 2015 net cash burn from operating and investing activities is primarily driven by an estimated net loss of $77 to $83 million, which includes an estimated $9 million of non-cash share-based compensation expense.

Upcoming Investor Conferences

Members of the senior management team will present and participate in investor meetings at the following upcoming investor conferences:

Live webcasts of the above presentations can be accessed through the investor relations section of the Company's website at www.prothena.com. Following the live presentations, replays of the webcasts will be available on the Company's website for 90 days following the presentation date.

About Prothena

Prothena Corporation plc is a late-stage clinical biotechnology company focused on the discovery, development and commercialization of novel protein immunotherapy programs for the potential treatment of diseases that involve amyloid or cell adhesion. The Company is developing antibody-based product candidates that target a number of potential indications including AL amyloidosis (NEOD001), Parkinson's disease and other related synucleinopathies (PRX002), and psoriasis and other inflammatory diseases (PRX003).

For more information, please visit the Company's web site at www.prothena.com.

Forward-looking Statements

This press release contains forward-looking statements. These statements relate to, among other things, the ability of our cash position to fund continued advancement of our program and becoming a commercial company; the potential for PRX002 to impact Parkinson's disease progression; the potential for our programs to be disease-modifying; the enrollment for our VITAL Amyloidosis Study for NEOD001; the timing of reporting additional data from our ongoing Phase 1/2 study for NEOD001; the timing of reporting further data from our Phase 1 single ascending dose study and initial data from our Phase 1 multiple ascending dose study for PRX002; the timing of initiating our Phase 1 single ascending dose and multiple ascending dose studies for PRX003; our anticipated net cash burn from operating and investing activities for 2015 and expected cash balance at the end of 2015; and our estimated net loss and non-cash share-based compensation expense for 2015. These statements are based on estimates, projections and assumptions that may prove not to be accurate, and actual results could differ materially from those anticipated due to known and unknown risks, uncertainties and other factors, including but not limited to the risks, uncertainties and other factors described in the "Risk Factors" sections of our Annual Report on Form 10-K filed with the Securities and Exchange Commission (SEC) on March 13, 2015 and our subsequent Quarterly Reports on Form 10-Q filed with the SEC. Prothena undertakes no obligation to update publicly any forward-looking statements contained in this press release as a result of new information, future events or changes in Prothena's expectations.

PROTHENA CORPORATION PLC
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
(unaudited - amounts in thousands except per share data)
 
 Three Months Ended
 March 31,
 20152014
Collaboration revenue  $ 593  $ 32,096
Revenue—related party 138
Total revenue 593 32,234
Operating expenses:    
Research and development 10,573 9,342
General and administrative 5,049 4,873
Total operating expenses 15,622 14,215
Income (loss) from operations (15,029) 18,019
Other income (expense), net 93 (16)
Income (loss) before income taxes (14,936) 18,003
Provision for income taxes 266 151
Net income (loss) $ (15,202)  $ 17,852
Net income (loss) per share attributable to holders of ordinary shares    
Basic $ (0.55)  $ 0.82
Diluted $ (0.55)  $ 0.78
Shares used to compute net income (loss) per share attributable to holders of ordinary shares    
Basic 27,401 21,884
Diluted 27,401 22,942
     
PROTHENA CORPORATION PLC
CONDENSED CONSOLIDATED BALANCE SHEETS
(unaudited - amounts in thousands)
 
 March 31,December 31,
 20152014
Assets    
Current assets:    
Cash and cash equivalents  $ 279,857  $ 293,579
Receivable from Roche 1,357 1,729
Receivable from related party 30 30
Deferred tax assets 163 167
Prepaid expenses and other current assets 3,012 3,770
Total current assets 284,419 299,275
Non-current assets:    
Property and equipment, net 2,956 3,121
Deferred tax assets, non-current 2,093 1,720
Other assets 117
Total non-current assets 5,166 4,841
Total assets  $ 289,585  $ 304,116
Liabilities and Shareholders' Equity    
Accrued research and development 3,662 2,285
Other current liabilities 5,882 9,754
Total current liabilities 9,544 12,039
Non-current liabilities 2,615 2,188
Total liabilities 12,159 14,227
Total shareholders' equity 277,426 289,889
Total liabilities and shareholders' equity  $ 289,585  $ 304,116
     
CONTACT: Investors: Tran Nguyen, CFO

         650-837-8535, IR@prothena.com

         

         Media: Angela Bitting

         925-202-6211, angela.bitting@prothena.com