PTC Therapeutics Reports First Quarter 2018 Financial Results and Provides a Corporate Update

SOUTH PLAINFIELD, N.J., May 9, 2018

"Over the past twenty years it has been our mission to bring clinically differentiated therapies to patients with rare disorders," said Stuart W. Peltz, Ph.D., Chief Executive Officer, PTC Therapeutics, Inc. "As we look forward, we are executing on that mission and consolidating our position as a leading rare disorder biotech company. We intend to continue to leverage our deep scientific expertise and world class commercial capabilities."

First Quarter 2018 Financial Highlights:

• Total revenues for the first quarter of 2018 were $56.1 million compared to $26.5 million in the same period in 2017. The change in total revenue was a result of Emflaza, which launched in May 2017, and the expanded commercial growth of Translarna.
• Translarna net product revenues were $36.8 million for the first quarter of 2018, representing 39% growth over $26.4 million reported in the first quarter of 2017.
• Emflaza net product revenues were $19.2 million for the first quarter of 2018.   
• GAAP R&D expenses were $31.4 million for the first quarter of 2018 compared to $27.4 million for the same period in 2017. Non-GAAP R&D expenses were $27.6 million for the first quarter of 2018, excluding $3.7 million in non-cash, stock-based compensation expense, compared to $22.9 million for the same period in 2017, excluding $4.5 million in non-cash, stock-based compensation expense. The increase in R&D expenses for the first quarter of 2018 as compared to the prior year period was primarily due to increased investment in research programs and advancement of the clinical pipeline.
• GAAP SG&A expenses were $33.0 million for the first quarter of 2018 compared to $25.5 million for the same period in 2017. Non-GAAP SG&A expenses were $29.0 million for the first quarter of 2018, excluding $4.0 million in non-cash, stock-based compensation expense, compared to $20.9 million for the same period in 2017, excluding $4.6 million in non-cash, stock-based compensation expense. The increase in SG&A expenses for the first quarter of 2018 as compared to the prior year period was primarily due to the continued commercial support for the Emflaza launch and continued growth of Translarna marketing activities.
• Net interest expense for the first quarter of 2018 was $3.3 million compared to $2.2 million in the same period in 2017. The increase in net interest expense for the first quarter of 2018 as compared to the prior year period was primarily due to increased interest expense related to the $40 million secured loan facility which we closed during the second quarter of 2017 partially offset by interest income from investments.
• Net loss for the first quarter of 2018 was $19.3 million compared to a net loss of $29.1 million for the same period in 2017.
• Cash, cash equivalents, and marketable securities totaled $178.3 million at March 31, 2018 compared to $191.2 million at December 31, 2017.
• Shares issued and outstanding as of March 31, 2018 were 41.8 million.
• In April 2018, PTC completed a public offering of 4,600,000 shares of common stock, resulting in net offering proceeds of $117.9 million.

2018 Guidance

• Full year 2018 net product revenues to be between $260 and $295 million. PTC anticipates Translarna net product revenue for the full year 2018 to be between $170 and $185 million. PTC projects a 5-year (December 31, 2022) compound annual growth rate of 15% for net product revenues representing continued strong growth year-over-year by increasing penetration in current countries and pursuing opportunities for label expansion. PTC anticipates Emflaza net product revenue for the full year 2018 to be between $90 and $110 million.   
• GAAP R&D and SG&A expense for the full year 2018 to be between $280 and $290 million.   
• Non-GAAP R&D and SG&A expense for the full year 2018 to be between $250 and $260 million, excluding estimated non-cash, stock-based compensation expense of approximately $30 million.

Key 2018 Corporate Highlights:

• Analyst Day highlighting PTC's 20-year commitment to developing therapeutics for rare disorders. PTC's management and research teams provided an in-depth update on the Company's commercial products, Translarna and Emflaza, its scientific platforms including alternative splicing with Spinal muscular atrophy in pivotal trials and two indications, Huntington's disease and Familial dysautonomia which the company anticipates will enter the clinic in 2020. In addition to these indications, PTC also provided updates on our niche oncology pipeline. There are currently two advanced candidates, PTC596 which is currently in the clinic, and PTC299, which PTC anticipates will re-enter the clinic later this year. In 2018, PTC is expecting to initiate clinical trials in two solid tumor indications for PTC596. PTC299, a DHODH inhibitor, is planned to enter clinical trials in hematological tumors in the third quarter of this year. PTC also has a second DHODH inhibitor fast follower currently in late-stage chemical optimization. A replay of the presentations and panel discussions can be found on the Investors page of the website.
• Encouraging early data from open-label FIREFISH study in Type 1 SMA babies. Data recently presented at the American Academy of Neurology 2018 Annual Meeting from Part 1 of the FIREFISH study, the dose finding portion, showed that there have been no drug-related safety findings leading to withdrawal at any dose level of the investigational molecule RG7916. In addition, no babies have required a tracheostomy or permanent ventilation since study initiation and no baby has lost the ability to swallow. The median age of first dose was 6.7 months and the 21 babies in the study received RG7916 for a duration of up to 14.8 months. It was reported in January that two babies had died from causes related to disease progression and the deaths were determined not to be drug related. The primary endpoint of Part 2, the confirmatory part of the FIREFISH study, is the proportion of patients sitting without support after 12 months on RG7916 treatment. Recruitment is ongoing globally for FIREFISH Part 2. The SMA program is a collaboration between PTC, Roche, and the SMA Foundation.
• Review of the Translarna Pediatric Label Expansion by the Committee for Medicinal Products for Human Use (CHMP) in progress. The application to expand the label of Translarna for the treatment of nonsense mutation DMD patients who are 2-5 years is currently under review by the CHMP in Europe and a decision is expected mid-year.
• Dystrophin study for US NDA for ataluren (Translarna) in DMD to begin by the end of 2018. The Office of New Drugs recommended a possible path forward for the ataluren NDA submission based on the accelerated approval pathway. This would involve a re-submission of an NDA containing the current data on effectiveness of ataluren with new data to be generated on dystrophin production. PTC is working to design such a study and expects to initiate such a study by the end of 2018.
• Successful closing of public offering. PTC offered 4,600,000 shares of common stock, successfully raising $117.9 million in the public market. PTC intends to use the net proceeds from this offering to fund its research and development efforts, including clinical trials and studies with respect to its products and product candidates and potential additional indications, including its programs for alternative splicing for the treatment of rare disorders and oncology, commercialization activities for Translarna for the treatment of nmDMD outside of the United States and Emflaza for the treatment of DMD in the United States and for working capital and other general corporate purposes.

Non-GAAP Financial Measures:
In this press release, the financial results and financial guidance of PTC are provided in accordance with accounting principles generally accepted in the United States (GAAP) and using certain non-GAAP financial measures. In particular, the non-GAAP financial measures exclude stock-based compensation expense. This non-GAAP financial measure is provided as a complement to financial measures reported in GAAP because management uses this non-GAAP financial measure when assessing and identifying operational trends. In management's opinion, this non-GAAP financial measure is useful to investors and other users of PTC's financial statements by providing greater transparency into the historical and projected operating performance of PTC and the company's future outlook. Quantitative reconciliations of non-GAAP financial measures to their closest equivalent GAAP financial measures are included in the tables below.

Today's Conference Call and Webcast Reminder:
Today's conference call will take place at 4:30 pm ET and can be access by dialing (877) 303-9216 (domestic) or (973) 935-8152 (international) five minutes prior to the start of the call and providing the passcode 3757748. A live, listen-only webcast of the conference call can be accessed on the Investor Relations section of the PTC website at www.ptcbio.com. A webcast replay of the call will be available approximately two hours after completion of the call and will be archived on the company's website for two weeks.