The Randomized Controlled Trial

The Randomized Controlled Trial
By: Rakhi Naik, MD

Eltrombopag for Thrombocytopenia in Patients with Cirrhosis Associated with Hepatitis C

STUDY OUTLINE
* Hypothesis: Eltrombopag can increase platelet counts in patient with hepatitis C cirrhosis.
* Design: Randomized controlled trial
* Setting: Multicenter trial in US & Europe
* Participants: 74 patients w/Hepatitis C cirrhosis
* Data Collection: Measurement of platelet counts before and after eltrombopag administration for 4 weeks; measurement of platelet counts after standard hepatitis C treatment with peg-interferon/ribavirin
* Outcome: Platelet counts, safety

BACKGROUND
* Chronic liver disease secondary to hepatitis C cirrhosis is often associated with significant thrombocytopenia.
* Thrombocytopenia in chronic hepatitis C infection is multifactorial in origin & is thought to be caused by:
o splenic sequestration (2/2 portal hypertension/hypersplenism)
o decreased thrombopoetin production (2/2 impaired hepatic synthetic function)
o bone marrow suppression (2/2 direct toxic effect of the hepatitis virus itself).

* Platelet counts below 75,000 are often not eligible for treatment with pegylated interferon & ribavirin because treatment itself leads to cytopenias in almost 100% of cases.

BACKGROUND
* Eltrombopag is an oral thrombopoetin receptor agonist that increases megakaryocyte proliferation and differentiation in animal models.

* Research questions:
o Can eltrombopag increase platelet levels in patients with untreated chronic hepatitis C cirrhosis?
o Can continued use of eltrombopag during hepatitis C treatment reduce treatment-related thrombocytopenia?
o What dose of eltrombopag is most effective for achieving these goals?

METHODS

* 22 centers in the United States & Europe were involved in recruitment.
* Inclusion criteria:
o 18 years of age or older
o Presence of serum HCV antibody levels
o Detectable serum HCV RNA levels
o Compensated liver disease (which is not defined explicitly)
o Thrombocytopenia with platelet levels between 20,000-70,000.
o Evidence of cirrhosis defined as: liver biopsy c/w cirrhosis, radiographic evidence of cirrhosis, or endoscopic evidence of varices

* Exclusion criteria:
o Pregnancy
o History of thrombosis
o HIV co-infection
o Hepatitis B co-infection

METHODS
Patients randomly assigned to placebo or eltrombopag (30mg, 50mg, 75mg daily) x 4 weeks
Any patient with plt count >70k or >100k was eligible for treatment with peg-interferon α-2a or peg-interferon α-2b, respectively. The decision to treat was left to the physician & patient.
Patients continued with their previous dose of eltrombopag during treatment.
Study designed by GlaxoSmithKline & academic principal investigator.
Daily eltrombopag doses were held if platelet count rose >200,000 and would be resumed when counts dropped to around 100,000

RESULTS
Approximate bilirubin (converted) 1.5+/- 1mg/dL. INR and creatinine not reported.
5 of total 74 patient listed here were excluded for baseline plt counts >75k but were ultimately eligible for the treatment phase.
Uneven number of patients in each arm because this was a mulicenter trial & not all sites contributed to all 4 arms.

RESULTS
Only 18 patients completed treatment. Only 1 placebo patient completed tx even though 7 were eligible.
Median platelet values prior to inferon treatment and % responders had significant p values compared to placebo

RESULTS
Pre-treatment platelet values, especially in the 50mg and 75mg eltrombopag arms, were statistically significant.
Platelet levels decreased with hep C treatment in all arms. P values for the eltrombopag groups vs. placebo were not statistically significant.
More patients in the eltrombopag arms completed treatment.

CONCLUSIONS/ IMPLICATIONS
* Eltrombopag increases platelet counts in a dose-dependent manner in patients with untreated chronic hepatitis C cirrhosis.
* Eltrombopag can be used to boost platelet counts in patients being considered for peg-interferon & ribavirin treatment.

STRENGTHS
* Clinical relevance: Thrombocytopenia is a very common complication of hepatitis C infection and ineligibility for treatment is a significant public health concern.
* Efficacy: Eltrombopag is extremely effective in increasing pre-interferon platelet counts (i.e. the study was able to demonstrate efficacy even though the sample size was low).
* Ease of use: Eltrombopag can be taken orally and has an easy daily dosing schedule.
* Safety: Eltrombopag has minimal side effects, which do not seem to be dose-dependent, and are not associated with significant morbidity.

WEAKNESSES
* Small sample size, especially in interferon treatment group (underpowered)
* Failed to standardize the protocol for initiation and cessation of interferon treatment phase.

* Lack of generalizability
o The investigators may have referred only patients with cirrhosis without portal hypertension to the study in order to select for a group who was more likely to benefit from treatment.
o Similarly, HCV viral loads were not taken into account.
* ? Clinical utility
o Could not ultimately answer question of whether pre-treatment with eltrombopag resulted in successful clearance of hepatitis C with treatment (i.e. whether the fact that more patients can receive interferon treatment actually leads to more patients who benefit from treatment).

The Randomized Controlled Trial.ppt