The US Food and Drug Administration (FDA) approved Doptelet on May 21, 2018 for the treatment of thrombocytopenia in adult patients with chronic liver disease (CLD) who are scheduled to undergo a procedure.
Doptelet represents the first thrombopoietin (TPO) receptor agonist approved in the United States for this indication.
Thrombocytopenia, a condition in which patients have a low platelet count, is the most common hematological abnormality in patients with CLD that often worsens with the severity of liver disease. It is estimated that approximately 15 percent of the 7.5 million patients with CLD have some form of thrombocytopenia.
In a study published in 2010, patients with severe thrombocytopenia (<75,000/µL) had a 31 percent incidence of procedure-related bleeding. As a result of the associated increased rate of bleeding, there is an increased risk for the CLD patient when undergoing common scheduled medical procedures such as liver biopsy, colonoscopy, endoscopy, and routine dental procedures.
As part of the co-promotion arrangement, Salix intends to deploy approximately 100 sales specialists who will promote DOPTELET to gastroenterology healthcare professionals. The Salix sales force will begin selling DOPTELET in mid-October 2018.
Dova will continue its commercial efforts targeting primarily hepatologists and interventional radiologists and certain other specialties. Pursuant to the agreement, Dova will pay Salix a quarterly fee based on net sales (as defined in the agreement) of DOPTELET prescribed by gastroenterologists in the U.S.
Dova Pharmaceuticals president and CEO Alex Sapir said: “We are delighted to be working with Salix, a company considered by many to have the preeminent gastroenterology sales force in the United States.
“Given Salix’s presence and strong reputation within large gastroenterology group practices coupled with the early interest we are seeing among the gastroenterology community, we are excited to see the impact this partnership will bring to DOPTELET and to patients.”
Salix Pharmaceuticals president Mark McKenna said: “Salix considers liver disease a strategic therapeutic area of focus, given our history and knowledge with XIFAXAN (rifaximin), an innovative medicine indicated for the treatment of overt hepatic encephalopathy (HE), a condition that is often a consequence of chronic liver disease.
“Adding DOPTELET to our portfolio will enable our sales force to promote yet another innovative product that addresses a true unmet need in the marketplace.”
DOPTELET (avatrombopag) is a second generation, once daily, orally administered TPO receptor agonist approved for the treatment of thrombocytopenia in adult patients with CLD who are scheduled to undergo a procedure. DOPTELET is designed to mimic the effects of TPO, the primary regulator of normal platelet production.
Two global Phase 3, double-blind, placebo-controlled trials (ADAPT-1 [N=231] and ADAPT-2 [N=204]), conducted in adults with thrombocytopenia (platelet count of less than 50,000/µL) and CLD, supported the FDA approval. Patients were assigned to either 40 mg or 60 mg of avatrombopag daily for five days based on their Baseline platelet counts (40 to <50,000/µmL or <40,000/µmL, respectively).
Avatrombopag was shown to be superior to placebo in increasing the proportion of patients not requiring platelet transfusions or rescue procedures for bleeding up to seven days following a scheduled procedure in both trials in both the 40 mg (ADAPT-1, 88% vs. 38%, p <0.0001; ADAPT-2, 88% vs. 33%; p<0.0001), and 60 mg (ADAPT-1, 66% vs. 23%, p <0.0001; ADAPT-2, 69% vs. 35%; p=0.0006) treatment groups.
Avatrombopag was also superior to placebo at the two secondary efficacy endpoints in each trial.
In the avatrombopag treatment groups, there was an increased proportion of patients achieving the target platelet count of ≥50,000/µmL on procedure day, and a greater magnitude of the change in mean platelet count from baseline to procedure day; all treatment differences between the avatrombopag and placebo treatment groups for each secondary endpoint were highly statistically significant with p values <0.0001.
The most common adverse reactions with avatrombopag included pyrexia, abdominal pain, nausea, headache, fatigue and edema peripheral. Portal vein thromboses have been reported in patients with CLD and in patients receiving TPO receptor agonists. One treatment-emergent event of portal vein thrombosis was reported in the ADAPT trials in an avatrombopag-treated patient.
XIFAXAN is a nonsystemic antibiotic that slows the growth of bacteria in the gut that are believed to be linked to symptoms of overt hepatic encephalopathy (HE). It has been proven to reduce the risk of overt HE recurrence and HE-related hospitalizations in adults.
Source: Company Press Release