Sanofi and Regeneron Pharmaceuticals, Inc. announced positive results from the phase 3 ODYSSEY ESCAPE trial evaluating Praluent (alirocumab) injection in patients with an inherited form of high cholesterol known as heterozygous familial hypercholesterolemia (HeFH), whose cholesterol levels required chronic, weekly or bi-weekly apheresis therapy. The trial met its primary endpoint, demonstrating that patients who added Praluent to their existing treatment regimen significantly reduced the frequency of their apheresis therapy by 75 per cent, compared to placebo (p<0.0001). Sixty-three per cent of patients treated with Praluent no longer required apheresis, compared to zero per cent of placebo patients. Apheresis is a procedure where bad (LDL) cholesterol is removed from the blood, in a process similar to kidney dialysis.

"This is the first time a PCSK9 inhibitor has shown in a clinical study that it reduced the frequency of apheresis therapy, an invasive, difficult to access, time-consuming and expensive treatment for some of the most difficult-to-treat patients," said Bill Sasiela, Ph.D, VP, Programme Direction, Regeneron. "The ODYSSEY clinical trial programme was designed to understand the effect of Praluent on many different patient populations with a high degree of unmet need who required further reduction of their LDL cholesterol."

Apheresis therapy is invasive and burdensome to patients, given that it can take more than three hours. Treatment may also be inconvenient and cost up to $100,000 for each patient per year in the US or up to €60,000 in Germany, where there are 200 centres and LDL apheresis is more frequently used. In the US there are only approximately 60 apheresis centres and many patients must travel significant distances for the procedure.

"Despite statins, a subset of patients with heterozygous familial hypercholesterolemia are unable to sufficiently reduce their LDL cholesterol, and require regular apheresis treatment," said Jay Edelberg, MD., Ph.D, head of cardiovascular development, Sanofi. "The results demonstrate that treatment with Praluent may help these patients decrease the frequency or even eliminate the need for apheresis."

The most common adverse events in the trial were fatigue (15 per cent Praluent; 10 per cent placebo), nasopharyngitis (10 per cent Praluent; 10 per cent placebo), diarrhea (10 per cent Praluent; 0 per cent placebo), myalgia (10 per cent Praluent; 5 per cent placebo), upper respiratory infection (7 per cent Praluent; 19 per cent placebo), headache (7 per cent Praluent; 5 per cent placebo), arthralgia (7 per cent Praluent; 10 per cent placebo), and back pain (5 per cent Praluent; 10 per cent placebo).

Detailed data will be presented at future medical congresses.

The completed phase 3 placebo-controlled ODYSSEY ESCAPE trial involved 62 patients from 14 treatment centres in the US and Germany. These patients were receiving regular baseline apheresis therapy at fixed intervals of every week or every 2 weeks prior to randomization. Patients were randomized to receive Praluent 150 mg (n=41) subcutaneously every 2 weeks or placebo (n=21), in addition to their existing treatment regimen. The double-blind treatment period comprised two intervals: for the first 6 weeks, patients remained on their established apheresis schedule at baseline, and for the following 12 weeks, apheresis frequency was adjusted based on the patient's LDL cholesterol response to treatment. ODYSSEY ESCAPE is part of the overarching phase 3 ODYSSEY programme, which includes more than 25,000 patients.

In July 2015, the companies announced that Praluent was approved for use in the US. Praluent is a PCSK9 (proprotein convertase subtilisin/kexin type 9) inhibitor indicated as adjunct to diet and maximally tolerated statin therapy for the treatment of adults with HeFH or clinical atherosclerotic CVD, who require additional lowering of LDL cholesterol. The effect of Praluent on CV morbidity and mortality has not been determined.

In September 2015, the European Commission approved the marketing authorisation for Praluent. In the EU, Praluent is approved for the treatment of adult patients with primary hypercholesterolemia (HeFH and non-familial) or mixed dyslipidemia as an adjunct to diet: a) in combination with a statin, or statin with other lipid-lowering therapies in patients unable to reach their LDL cholesterol goals with the maximally-tolerated statin or b) alone or in combination with other lipid-lowering therapies for patients who are statin intolerant, or for whom a statin is contraindicated. The effect of Praluent on CV morbidity and mortality has not yet been determined.

This medicinal product is subject to additional monitoring. This will allow quick identification of new safety information. Healthcare professionals are asked to report any suspected adverse reactions.

Praluent can cause serious side effects, including allergic reactions that can be severe and require treatment in a hospital.