Gilead two-drug hep C combination cures 94% of genotype 1 patients in eight weeks

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A two-drug combination of sofosbuvir and ledipasvir cured 94% of previously untreated patients with genotype 1 hepatitis C infection after eight weeks, without the need for ribavirin, Gilead Sciences announced on Wednesday.

The results released on 18 December come from one of three trials of the combination, ION-3. Two other studies tested the combination for longer periods and with both previously untreated and treatment-experienced patients, and showed similarly high cure rates after 12 or 24 weeks of treatment, with or without ribavirin.

Gilead Sciences said that the very high cure rates observed in the studies mean that it will be possible to speed up registration plans for the combination. The company now plans to submit a licensing application in the first quarter of 2014, which means that the combination could receive marketing approval in the United States in the final quarter of 2014.

Glossary

cirrhosis

Severe fibrosis, or scarring of organs. The structure of the organs is altered, and their function diminished. The term cirrhosis is often used in relation to the liver. 

treatment-experienced

A person who has previously taken treatment for a condition. Treatment-experienced people may have taken several different regimens before and may have a strain of HIV that is resistant to multiple drug classes.

naïve

In HIV, an individual who is ‘treatment naïve’ has never taken anti-HIV treatment before.

cure

To eliminate a disease or a condition in an individual, or to fully restore health. A cure for HIV infection is one of the ultimate long-term goals of research today. It refers to a strategy or strategies that would eliminate HIV from a person’s body, or permanently control the virus and render it unable to cause disease. A ‘sterilising’ cure would completely eliminate the virus. A ‘functional’ cure would suppress HIV viral load, keeping it below the level of detection without the use of ART. The virus would not be eliminated from the body but would be effectively controlled and prevented from causing any illness. 

treatment-naïve

A person who has never taken treatment for a condition.

Sofosbuvir, a nucleotide polymerase inhibitor recently approved in the United States and European Union, was paired with ledipasvir, a NS5a inhibitor, in three studies testing different durations of treatment in various populations.

The ION-1 study compared 12 and 24 weeks of treatment with sofosbuvir and ledipasvir, with and without ribavirin, in previously untreated patients with genotype 1 infection. Approximately 15% had cirrhosis.

The ION-2 study compared 8, 12 and 24 weeks of treatment with sofosbuvir and ledipasvir, with and without ribavirin, in treatment-experienced patients with genotype 1 infection who had experienced failure of previous triple therapy with pegylated interferon, ribavirin and a protease inhibitor. Approximately 20% had cirrhosis.

The ION-3 study compared 8 and 12 weeks of treatment with sofosbuvir and ledipasvir without ribavirin, with 12 weeks of treatment with sofosbuvir and ledipasvir with ribavirin. All patients in this study were previously untreated and had genotype 1 infection. None had cirrhosis.

Results

Gilead released 8- and 12-week results of ION 1, 2 and 3. 24-week results of ION-1 will be released in the first quarter of 2014.

Study

Population

Treatment

Duration

SVR12

ION-1

Genotype 1

Treatment-naive

N = 865

SOF/LDV

12 weeks

97.7%

SOF/LDV + RBV

12 weeks

97.2%

SOF/LDV

24 weeks

Not available

SOF/LDV + RBV

24 weeks

Not available

ION-2

Genotype 1

Treatment-experienced

N = 440

SOF/LDV

12 weeks

93.6%

SOF/LDV + RBV

12 weeks

96.4%

SOF/LDV

24 weeks

99.1%

SOF/LDV + RBV

24 weeks

99.1%

ION-3

Genotype 1

Treatment-naïve

N = 647

SOF/LDV

8 weeks

94.0%

SOF/LDV + RBV

8 weeks

93.1%

SOF/LDV

12 weeks

95.4%

4.1% of study participants in the study arms released to date failed to achieve SVR12. Of these, just over half (36 patients out of 62, or 2.4% of all participants, experienced virologic failure: 35 due to relapse and only one patient due to on-treatment breakthrough (this patient was non-adherent to therapy). Twenty-six patients (1.7%) were lost to follow-up or withdrew consent.

A more detailed breakdown of performance of each regimen and treatment duration in patients with cirrhosis will be reported at a future scientific meeting.

Gilead Sciences said that the ribavirin-sparing combination was better tolerated: anaemia, a common side-effect of ribavirin, was reported in 9.2% of patients who received ribavirin, compared to 0.5% of patients who received sofosbuvir and ledipasvir without ribavirin. The most frequent side effects of sofosbuvir and ledipasvir were headache and fatigue.

The results of these studies will pose a significant challenge to other developers of interferon-free combinations for the treatment of hepatitis C. An eight-week treatment course with two drugs will compare favourably in the eyes of many patients and physicians to a longer duration of treatment, although a major US pharmaceutical benefits company, which negotiates process on behalf of insurers and managed-care organisations has warned that it may only pay for more expensive hepatitis C drugs if they are more effective. Convenience of dosing may not be enough to justify a higher price.