Horizon Pharma, Inc. announced it has submitted a New Drug Application (NDA) to the United States Food and Drug Administration (US FDA) for lodotra, a proprietary modified (delayed)-release formulation of low-dose prednisone, for the treatment of active rheumatoid arthritis (RA). Lodotra is currently approved for marketing in 16 European countries.

“The NDA submission for lodotra represents an important milestone for our continued growth in the United States market,” said Timothy P Walbert, chairman, president and chief executive officer, Horizon Pharma. “If approved, lodotra may offer an important new treatment option for patients struggling with the signs and symptoms of rheumatoid arthritis.”

The lodotra NDA submission was primarily based on results from the Circadian Administration of Prednisone in RA (CAPRA-2) trial, a pivotal, 12-week, double-blind, placebo-controlled phase III trial involving 350 RA patients. Both treatment groups in the trial continued to receive standard of care RA treatment with a disease-modifying anti-rheumatic drug (DMARD). Results from CAPRA-2 demonstrated: a statistically significant improvement in American College of Rheumatology 20 (ACR20) response criteria, the primary study endpoint, for patients who were treated with lodotra compared to the placebo group (48.5% vs. 28.6%; p-value = 0.0002).

A statistically significant improvement in ACR50 response compared to placebo (22.7% vs. 9.2%; p-value = 0.0027) and an improvement in the more stringent ACR70 response criteria (7.0% vs. 2.5%; p-value = 0.0955). A statistically significant reduction in morning stiffness compared to patients in the placebo group (56.5% vs. 33.3%; p-value = 0.0008).

In this study, the most commonly reported treatment-emergent adverse events were joint pain (10.4% for lodotra compared to 20.2% for placebo), RA flare (6.5% for lodotra compared to 9.2% for placebo), nasopharyngitis, or inflammation of the nasal passages, (4.8% for lodotra compared to 3.4% for placebo) and headache (3.9% for lodotra compared to 4.2% for placebo).

Additional data in the NDA submission included results from the CAPRA-1 study, which was a 12 week, double-blind, placebo-controlled study in Europe evaluating 288 RA patients. CAPRA-1 compared the night-time administration of lodotra with the morning administration of immediate release prednisone at the same individual dose (average dose of 6.7 mg). Results from CAPRA-1 demonstrated: a statistically significant reduction in morning stiffness compared to patients in the immediate release group, the primary outcome of the trial, (22.7% for lodotra compared to 0.4% for immediate release prednisone (p-value = 0.045)). Patients treated with lodotra had a reduction in IL-6 levels of approximately 29% (relative median change), which was statistically significant, while corresponding IL-6 levels following treatment with immediate release prednisone remained constant.

The most commonly reported treatment-emergent adverse events were a flare in RA-related symptoms (7.6% for lodotra compared to 9.0% for immediate release prednisone), abdominal pain (3.5% for lodotra compared to 5.6% for immediate release prednisone), nasopharyngitis (2.8% for lodotra compared to 5.6% for immediate release prednisone), headache (4.2% for lodotra compared to 2.8% for immediate release prednisone) and flushing (2.8% for lodotra and 4.2% for immediate release prednisone).

Following the 12-week CAPRA-1 study, patients were followed in a nine-month, open-label extension study, which included 249 RA patients, 219 of whom completed the extension study. Results showed that patients who continued treatment with lodotra experienced a 55% reduction in the duration of morning stiffness. Further, patients newly assigned to lodotra exhibited a 45% reduction in the duration of morning stiffness over the nine-month course of this extension study. These patients also experienced a 50% median reduction in IL-6 levels that also corresponded to improvements in the duration of morning stiffness following daily administration of lodotra.

The most commonly reported treatment-emergent adverse events in the extension study were a flare in RA-related symptoms (14.5%), flushing (5.2%), upper respiratory tract infections (2.8%), back pain (2.8%) and weight increase (2.8%). Adverse events indicative of aggravated hypothalamic-pituitary adrenal, or HPA, axis suppression, typical of high dose prednisone administration, were not observed.

Lodotra is a proprietary modified (delayed)-release formulation of low-dose prednisone. Prednisone, the active ingredient in lodotra, is currently US FDA approved for RA and commonly used to inhibit the production of various pro-inflammatory cytokines, which are proteins associated with joint inflammation in RA.

A phase III clinical trial of lodotra for the treatment of polymyalgia rheumatica (PMR) is being planned. This indication is not included in the NDA.

RA is a chronic disease that causes pain, stiffness and swelling, primarily in the joints. RA affects approximately 1.8 million people in the US and is not associated with factors such as ageing. RA occurs when the body's immune system malfunctions, attacking healthy tissue and causing inflammation, which leads to pain and swelling in the joints, and may eventually cause permanent joint damage and painful disability. The primary symptoms of RA include progressive immobility and pain, especially in the morning, with long-term sufferers experiencing continual joint destruction for the remainder of their lives.

Horizon Pharma, Inc. is a biopharmaceutical company that is developing and commercializing innovative medicines to target unmet therapeutic needs in arthritis, pain and inflammatory diseases.