Press Release

<< Back
View printer-friendly version

Spark Therapeutics Presents Preliminary Data on Investigational SPK-8011 Phase 1/2 Dose-escalation Clinical Trial in Hemophilia A at 59th American Society of Hematology (ASH) Annual Meeting and Exposition

Preliminary data as of Dec. 6, 2017, show a 100-percent reduction in annualized bleeding rate (ABR) and 98-percent reduction in annualized infusion rate (AIR) in first four participants

PHILADELPHIA, Dec. 11, 2017 (GLOBE NEWSWIRE) -- Spark Therapeutics (NASDAQ:ONCE), a fully integrated gene therapy company dedicated to challenging the inevitability of genetic disease, today announced that it has dosed seven participants in the Phase 1/2 clinical trial of SPK-8011 in hemophilia A. The first four participants, who have been followed at least 12 weeks post infusion, have reduced their overall annualized bleeding rate (ABR), calculated based on data after week four, by 100 percent (calculated based on data after week four; 82 percent based on data after infusion) to a mean of 0 (1) annualized bleeds as of the data cutoff, compared to a mean of 5.5 annualized bleeds before a single administration of SPK-8011. Similarly, their overall annualized infusion rate (AIR) was reduced approximately 98 percent (calculated based on data after week four; 96 percent based on data after infusion) to a mean of 1.2 (2.5) annualized infusions as of the data cutoff, compared to a mean of 57.8 annualized infusions before SPK-8011 administration. No serious adverse events have been observed to date. These data were presented today by Lindsey A. George, M.D., attending physician in the Division of Hematology at Children’s Hospital of Philadelphia and principal investigator of the trial, at the 59thAmerican Society of Hematology (ASH) Annual Meeting and Exposition in Atlanta.

Investigational SPK-8011, a novel bio-engineered adeno-associated viral (AAV) vector utilizing the AAV-LK03 capsid, also referred to as Spark200, containing a codon-optimized human factor VIII gene under the control of a liver-specific promoter, is being studied as a potential one-time gene therapy for hemophilia A. It is the second investigational hemophilia gene therapy to emerge from Spark Therapeutics’ leading gene therapy platform. Spark Therapeutics retains global commercialization rights to SPK-8011.

“While still early in the dose-escalation clinical trial of SPK-8011, we are encouraged these data show clinically significant reductions in ABR and AIR with no serious adverse events reported to date,” said Katherine A. High, M.D., president and head of research and development at Spark Therapeutics. “We look forward to continuing to enroll additional participants to further increase our understanding of how to optimize the potential efficacy of this investigational gene therapy.”

As of the Dec. 6, 2017, data cutoff, two participants have received a single administration of SPK-8011 at an initial dose of 5 x 1011 vector genomes (vg)/kg body weight and have now been followed for more than 40 weeks and 30 weeks. During this time, participant one has achieved sustained expression with a mean factor VIII activity level after week 12 of 10 percent (range as of the data cutoff: 7 to 11 percent). Participant two has shown different kinetics of factor VIII expression. His factor VIII level, as of the data cutoff, is 37 percent, and the mean factor VIII level since week 12 is 16 percent (6 to 37 percent).

Two additional participants, infused at a dose of 1 x 1012 vector genomes (vg)/kg body weight, have also achieved therapeutic levels of factor VIII. They have now been followed for 19 weeks and 14 weeks and have mean sustained factor VIII activity levels of 9 percent (7 to 12 percent) and 13 percent (7 to 24 percent) of normal, respectively, as of the data cutoff. Both participants have completed a precautionary tapering course of corticosteroids.

Three more participants have been infused, one at the 1 x 1012 vector genomes (vg)/kg body weight dose and two at a dose of 2 x1012 vector genomes (vg)/kg body weight. Results for these three participants are too early to report as of the data cutoff.

To date, none of the seven infused participants has reported a serious adverse event, including no factor VIII inhibitors, no thrombotic events and no factor VIII activity levels that may increase risk of thrombosis.

Please see Dr. George’s presentation, with data graphs, here.

About Hemophilia A
Hemophilia is a rare genetic bleeding disorder that causes the blood to take a long time to clot because of a deficiency in one of several blood clotting factors. People living with hemophilia are at risk of excessive and recurrent bleeding spontaneously and from modest injuries, which have the potential to be life threatening. There are approximately 15,000 people with hemophilia A in the U.S. and 19,000 in the five major European countries. Hemophilia A is about four times as common as hemophilia B. Hemophilia A is characterized by mutations in the factor VIII gene (F8), which lead to deficient blood coagulation and an increased risk of bleeding or hemorrhaging. The current standard of care for hemophilia A requires recurrent intravenous infusions of either plasma-derived or recombinant factor VIII to control and prevent bleeding episodes. There exists a significant need for novel therapeutics to treat people living with hemophilia.

About Spark Therapeutics
At Spark Therapeutics, a fully integrated company committed to discovering, developing and delivering gene therapies, we challenge the inevitability of genetic diseases, including blindness, hemophilia and neurodegenerative diseases. We have successfully applied our technology directed to the retina and liver, and currently have four programs in clinical trials or under regulatory review, including the first potential gene therapy for a genetic disease in the United States and product candidates that have shown promising early results in patients with hemophilia. At Spark, we see the path to a world where no life is limited by genetic disease. For more information, visit, and follow us on Twitter and LinkedIn.

Cautionary note on forward-looking statements
This release contains "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995, including statements regarding the company's SPK-FIX program. The words ‘‘anticipate,’’ ‘‘believe,’’ ‘‘expect,’’ ‘‘intend,’’ ‘‘may,’’ ‘‘plan,’’ ‘‘predict,’’ ‘‘will,’’ ‘‘would,’’ ‘‘could,’’ ‘‘should,’’ ‘‘continue’’ and similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. We may not actually achieve the plans, intentions or expectations disclosed in our forward-looking statements, and you should not place undue reliance on our forward-looking statements. Any forward-looking statements are based on management's current expectations of future events and are subject to a number of risks and uncertainties that could cause actual results to differ materially and adversely from those set forth in, or implied by, such forward-looking statements. These risks and uncertainties include, but are not limited to, the risk that (i):  the  factor VIII expression levels seen in our trial participants and the reduction in ABR and AIR may not be maintained; (ii) our lead SPK-FVIII product candidate, SPK-8011, may not produce sufficient data in our Phase 1/2 clinical trial to warrant further development; and (iii) any one or more of our product candidates in preclinical or clinical development will not successfully be developed and commercialized. For a discussion of other risks and uncertainties, and other important factors, any of which could cause our actual results to differ from those contained in the forward-looking statements, see the "Risk Factors" section, as well as discussions of potential risks, uncertainties and other important factors, in our Annual Report on Form 10-K, our Quarterly Reports on Form 10-Q and other filings we make with the Securities and Exchange Commission. All information in this press release is as of the date of the release, and Spark undertakes no duty to update this information unless required by law.

Investor Contact:     
Ryan Asay
(215) 239-6424                                                                                                   

Media Contact:
Monique da Silva 
(215) 282-7470

Primary Logo

Source: Spark Therapeutics, Inc.