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Hepatitis C Pipeline

July 2014

By Tracy Swan

BONANZA! The Gold Rush Is Under Way

The direct-acting antiviral (DAA) era officially began in late 2013, with approval of the first all-oral treatment for hepatitis C virus (HCV) genotypes 2 and 3. A hefty pipeline will increase HCV treatment options, especially for people with genotype 1, by mid-to-late 2014. Cure rates above 95 percent—after only 12 weeks of treatment—have become commonplace in HCV clinical trials.* DAAs have been miraculous for people with cirrhosis, HIV/HCV coinfection, and before and after liver transplantation.

* A sustained virologic response (SVR)—meaning that hepatitis C virus becomes undetectable during treatment and remains undetectable for at least 12 weeks after treatment is finished—is equivalent to a cure.

But the outrage about sky-high DAA prices is quickly overtaking excitement about these wonder drugs. Advocates and clinicians are forced to fight for access to outrageously expensive drugs for people who cannot wait for affordable options—or watch people die from a curable infection.

Gilead’s nucleotide polymerase inhibitor, sofosbuvir—the backbone of most DAA regimens—is US$1,000 per tablet. Such a price limits access to this lifesaving drug, even in high-income countries, where the market for DAAs is projected to reach over US$100 billion by 2023.1


Gold Fever!

Analysts at Evaluate Pharma have deemed sofosbuvir “the most valuable research and development product [to date].”2 At 21 weeks after launch, sofosbuvir sales have reached almost US$3 billion dollars, and analysts predict sales of up to US$9 billion dollars in 2014.3

If only 500,000 people in the U.S.—less than a quarter of those with chronic HCV—were treated with sofosbuvir, sales would reach US$45 billion dollars.


DAAs Offer a Tantalizing Possibility: Global HCV Eradication

At least 185 million people have been infected with hepatitis C virus.4 HCV is most prevalent in low- and middle-income countries (LMICs).4 Egypt has the highest hepatitis C prevalence (14%) followed by Cameroon (13.8%), Uganda (6.6%), Uzbekistan (6.5%), the Democratic Republic of Congo (6.4%), and Pakistan (5.9%).5,6,7 In populous LMICs such as China and India, HCV prevalence is lower, but the sheer number of people with HCV—almost 30 million in China and over 18 million in India—is staggering.5,6,7

Less toxic, more effective, and more convenient HCV treatment is a global boon for individual and public health. In April of 2014, the World Health Organization (WHO) issued Guidelines for the Screening, Care and Treatment of Persons with Hepatitis C.8 The Guidelines are essential for informing decision makers and health care workers, but high-priced diagnostics and drugs will impede their implementation. “I hope these guidelines will help to promote a reduction in price and thereby an increase in access,” said Stefan Wiktor, Team Lead of the WHO Global Hepatitis Programme.9

Global eradication of HCV is possible, if pharmaceutical companies will allow generic DAA production in LMICs. “Competition and generic production really are the keys to reductions in prices,” says Dr. Wiktor.10 DAAs can be produced inexpensively, according to an analysis from the University of Liverpool (using molecular weight, chemical structure, complexity, dose, and cost of comparable HIV antiretroviral agents). The actual production cost for 12 weeks of a single DAA ranges from US$10 to US$270, assuming an annual volume of 1–5 million treatment courses (see table 1).5

The Médecins Sans Frontières (MSF) Access Campaign has set a target price for the complete package of HCV diagnostics, care, and DAA treatment in LMICs: less than US$500.11

Table 1. DAA Regimens: Production Costs and Characteristics5,12,13,14,15,16,17,18

Regimen ($/gram)

Cost/Duration

Characteristics

Daclatasvir ($2–6/gram)
+ sofosbuvir ($2-4/gram)

 

$78–166/12-week

Pangenotypic

SVR-24: 89–100% in phase II

Ongoing phase III trials in HIV coinfection or cirrhosis/posttransplant
May be possible to shorten treatment to 8 weeks in some populations

Daclatasvir
+ ribavirin* ($0.25–0.75/gram)
+ sofosbuvir

$112–224/12-week

Pangenotypic, RBV use may be unnecessary

Ongoing phase III trial in cirrhosis/posttransplant

ribavirin*
+ sofosbuvir

$102–194/12-week

$204–388/24-week

Tx duration varies by HCV genotype;

SVR-12, in treatment-naive:

Genotype 1 (24 weeks of treatment) : 70%

Genotype 2 (12 weeks of treatment): 93%

Genotypes 3 and 4 (24 weeks of treatment): >90–100%

Less effective in cirrhosis; may be possible to shorten treatment to
8 weeks in some populations

Simeprevir ($10–21/gram)
+ sofosbuvir

$198–406/12-week

Effective against genotypes 1 and 4 (studied only in genotype 1);
SVR-12 in null responders with mild-fibrosis, precirrhosis, and

Child–Pugh class A cirrhosis: 93%

SVR-12 in treatment-naive, precirrhosis, or Child–Pugh class A

cirrhosis: 93%

Ribavirin*
+ simeprevir
+ sofosbuvir

$232–600/12-week

Adding RBV did not increase SVR in a phase II trial;

ongoing phase III trials do not include RBV

* Weight-based dosing


HCV Diagnostics

Lack of access to HCV viral-load testing has been cited as a barrier to treatment scale-up, since it is essential—viral load is used to diagnose hepatitis C infection and to monitor response to, and outcome of, HCV treatment. Although DAA regimens require less monitoring than PEG-IFN-based treatment, the high price of, and technology required for, HCV viral-load testing curtails the opportunity to diagnose and treat hepatitis C.

AIDS activists—who are fighting to reduce the price of HIV viral-load testing in LMICs—may come to the rescue. Since the same technology can be used for both viruses, affordable HIV viral-load testing offers the potential to increase access to HCV viral-load testing. Other barriers will remain, even with affordable testing: the need for cold-chain transportation, expensive machinery, laboratory space, trained personnel, and stable electricity.

Lack of innovation in diagnostics is hindering global efforts to screen, diagnose, and treat HCV. Development of reliable, less complicated rapid and point-of-care testing is long overdue. The WHO has developed criteria for evaluating HIV point-of-care devices, known as ASSURED (affordable, sensitive, specific, user-friendly, rapid, and robust, equipment-free, and deliverable to end users).19


Choosing the Best First-Line DAA Regimen

I have the simplest tastes. I am always satisfied with the best.
—Oscar Wilde


Global progress against HCV has been hobbled by complex diagnostics and monitoring requirements, and suboptimal, expensive, and difficult-to-tolerate treatment. DAAs can radically simplify HCV treatment and reduce diagnostic and monitoring requirements. In the United States, the demand for HCV treatment is likely to outstrip the capacity of specialists to deliver it. Simple DAA regimens will make it easier for nonspecialist providers to begin treating HCV in people with less advanced liver disease.

The characteristics of optimal HCV regimens for resource-limited settings—simplicity, convenience, and manageability—are also relevant for high-income countries. Desirable characteristics for DAA regimens (assuming affordability, safety, and tolerability) include:

  • Highly effective—cure rate of >80%—regardless of host and viral factors, especially in populations most likely to be prioritized for treatment (e.g., people with cirrhosis or HIV/HCV);
     
  • Pangenotypic, potent regimens with a high barrier to drug resistance;
     
  • Simple regimens that obviate a battery of pretreatment testing (IL-28B genotyping, viral subtyping, and drug resistance), and do not require extensive monitoring for safety, efficacy, and treatment outcome;
     
  • Manageable drug-drug interactions, allowing coadministration with commonly used medications (treatment for HIV and tuberculosis, methadone, buprenorphine, statins, hormonal contraception, and psychotropic medications);
     
  • Safety during pregnancy and nursing;
     
  • Safety and efficacy in pediatrics;
     
  • Fixed treatment duration (preferably ≤12 weeks);
     
  • No food requirement;
     
  • No cold storage needed;
     
  • Once-daily dosing; and
     
  • Low pill burden.

Table 2. DAA Regimens: Desirable Characteristics

Regimen/
Sponsor(s)

Status

Pangenotypic

Safe, effective in advanced liver disease

Acceptable tolerability (data may be limited)

Manageable drug-drug interactions

Duration ≤12 weeks

QD

Studied in HIV/HCV

SVR

≥90%

 

Fixed-dose combination (FDC): ABT-267/ ABT-333/ ABT-450/r + RBV

AbbVie

2014 Expected approval

 

X

X

?

X

 

X

X

Asunaprevir
+ BMS-791325
+ daclatasvir

BMS

2015 Expected approval

 

?

X

?

X

 

 

X

Daclatasvir
+ sofosbuvir

BMS

2014 Expected approval

G1-3; ongoing trials in all genotypes

X

X

X

X

X

X

X

FDC: sofosbuvir/ ledipasvir
Gilead

2014 Expected approval

 

X

X

?

X

X

X

X

FDC: sofosbuvir/
GS-5816

Gilead

2015 Possible approval

X

?

X

?

X

X

X

X

Sofosbuvir
+ RBV
Gilead

Approved 2013

X

X

X

X

 

 

X

Only

in G2

Sofosbuvir
+ PEG/IFN/ RBV

Gilead/Roche/
Merck; generics

Approved 2013

X

?

?

X

X

 

X

X

Sofosbuvir
+ simeprevir
(off-label)
Gilead/Janssen

Approved 2013

 

X*

X

X

X

X

X

X

MK-5172
+ MK-8742

Merck

2015 Expected approval

Studies in G4–6 planned; also being studied with sofosbuvir in G3

?

X

?

?

X

X

X

*Child–Pugh class A cirrhosis only


There are no data on these regimens in people who inject drugs, during pregnancy and nursing, or in pediatrics (ribavirin is contraindicated in pregnancy, during nursing and in children under three years old). There are virtually no data on DAA safety, efficacy, and tolerability in people with common comorbidities.

Sofosbuvir, simeprevir, and ribavirin can be stored at room temperature (below 84°F or 28°C); sofosbuvir can be taken with or without food; ribavirin and simeprevir should be taken with food. Data on food and storage requirements for experimental DAAs are not available. All regimens have a low pill burden and require limited monitoring during treatment.


From the Graveyard to the Gravy Train: Nucleoside/tide Polymerase Inhibitors

Sofosbuvir—the only approved nucleoside/tide polymerase inhibitor—is pangenotypic, potent, has a high resistance barrier, few drug-drug interactions, and has proven to be safe and tolerable.

Developing HCV nucleoside/tide polymerase inhibitors is tricky, despite their potential. DAAs from this class (particularly guanosine-based nucleotides) have been discontinued because they were too toxic (BMS-986094 [renal and cardiac toxicity]; NM283 [gastrointestinal toxicity]; R1626 [lymphopenia and neutropenia]; PSI-983 [liver toxicity]).20,21 Mericitabine is the only other nucleotide to have advanced into phase III, but further development seems to be stalled, possibly permanently. VX-135, a once promising candidate, has entered pharmaceutical limbo since Vertex announced plans to license it out.

But there may be more nucleotides: after setbacks with NM283, IDX184, and IDX19368—all discontinued—Idenix forged ahead with development of two uridine nucleotide polymerase inhibitors (IDX21437 and IDX21459). In June of 2014, Merck purchased Idenix. Achillion has a uridine nucleotide, ACH-3422, in a phase I trial.


HCV TREATMENT LANDSCAPE

Note: Comprehensive information on DAA regimens is available at http://www.pipelinereport.org/2014/hcv/update.

Genotype 1: There Is No Balm in Gilead

Despite the remarkably rapid progress against HCV, patients with genotype 1 and cirrhosis—who urgently need treatment to avert transplantation, liver cancer, and death—are still waiting for DAAs, since peginterferon may be too dangerous, too toxic, or ineffective. Yet there is an effective DAA regimen for genotype 1—even in null responders with compensated cirrhosis.

In COSMOS, a phase II trial, Janssen’s simeprevir and Gilead’s sofosbuvir were highly effective and safe for people with HCV genotype 1 and compensated cirrhosis, regardless of treatment history; cure rates over 90 percent were reported after 12 weeks of treatment.22,23 Despite the need for, and promise, of this regimen, Gilead declined to continue codevelopment with Janssen.

Simeprevir and sofosbuvir have been approved separately. The combination was not approved by regulatory agencies, but treatment guidelines in the United States and the European Union recommend off-label use for people with HCV genotype 1 who are ineligible for interferon-based treatment.24,25 Gilead’s monopolistic approach has limited awareness of off-label HCV treatment options among physicians; according to a Decision Resources report, “a notable share” of gastroenterologists and infectious disease specialists continue to prescribe suboptimal boceprevir- and telaprevir-based treatment to genotype 1 patients (these regimens are no longer recommended by the American Association for the Study of Liver Diseases, the Infectious Diseases Society of America, or the European Association for the Study of the Liver).26

Collaboration between sponsors facilitates development of potentially lifesaving regimens. Unfortunately, commercial interests have trumped medical need—it is unacceptable that Gilead’s desire to dominate the HCV market has delayed or complicated access to the best possible treatment.

Climb Every Mountain: Curing Genotype 3

Despite a gushing pipeline, there are still critical gaps in HCV treatment—especially in genotype 3, which has global distribution. An interferon-free cure-all for genotype 3—especially for people with cirrhosis—remains elusive, although there are DAA regimens in clinical trials. BMS is sponsoring ALLY-3, a 150-person phase III trial of daclatasvir and sofosbuvir in genotype 3 (treatment-naive and treatment-experienced). Merck is launching a phase IIb trial of sofosbuvir with a fixed-dose combination of MK-5172 (protease inhibitor) and MK-8742 (NS5A inhibitor) for 8 or 12 weeks.

There are three strategies for increasing efficacy of sofosbuvir-based treatment in genotype 3: adding peginterferon to a 12-week regimen of sofosbuvir and ribavirin; combining sofosbuvir with another DAA (daclatasvir, ledipasvir, or GS-5816); or extending the duration of treatment with sofosbuvir and ribavirin to 16 or 24 weeks. Each strategy has limitations. Peginterferon is unappealing to, or contraindicated for, many people; daclatasvir, ledipasvir, and GS-5816 are not yet approved (limiting access to people who are eligible for clinical trials, or early access and named-patient programs), and the cost of a 24-week regimen (US$168,000 for sofosbuvir) is likely to make payers balk. 

High drug prices—not the basic human right to health care—are the bedrock of cost per cure.* Other factors, such as a country’s disease burden, and the resources it has for hepatitis C are not considered. Cost per cure attempts to transform unaffordable medicines into bargains, by reducing health care costs in the future (for example, HCV cost per cure is less expensive than liver transplantation).

* “Cost per cure” is calculated by dividing a standard cost reference by the sustained virologic response (or cure) rate in a specific population, then multiplying it by 100.


Table 3. Genotype 3: Regimen, SVR-12, Relapse, and Cost15,16,18,27,28,29,30,31,32

Regimen/Duration

Population

SVR-12

Relapse

Estimated cost (U.S.-only; RBV 1,000 mg/day)*

Cost per cure

(drugs only)

PEG-IFN/RBV, 24 weeks

Tx-naive

63% (110/176)

9% (16/176)

$20,478

$32,504

SOF + PEG-IFN/RBV,
12 weeks

Tx-naive

100% (18/18)

0%

$94,239

$94,239

Tx-experienced

83% (20/24)

8% (2/24)

$113,540

SOF + RBV, 12 weeks

Tx-naive

56% (102/183)

40% (72/179)

$84,449

$150,801

Tx- naive,

HIV-positive

67% (28/42)

26% (11/42)

$126,043

Tx-experienced

30% (19/64)

68% (44/64)

$281,496

SOF + RBV, 16 weeks

Tx-experienced

62% (39/63)

38% (24/63)

$112,598

$181,610

SOF + RBV, 24 weeks

Tx-naive

93% (98/105)

5% (5/105)

$168, 898

$181,610

Tx-experienced

77% (112/145)

20% (29/144)

$219,348

SOF + DCV ± RBV, 24 weeks

Tx-naive

89% (16/18)

<1% (1/18)

$211,974/$212,872**

$238,173/
$239,182

SOF/LDV ± RBV, 12 weeks

Tx-naive

64% (16/25)

32% (8/24)

?

?

Tx-naive (+ RBV)

100% (26/26)

SOF + GS-5816 (25 mg or
100 mg), 12 weeks

Tx-naive, 25 mg dose

93% (25/27)

<1% (1/27)

?

?

Tx-naive, 100 mg dose

93% (25/27)

<1% (1/27)

 

 

*Data from www.goodrx.com (Accessed on May 2, 2014).
**Daclatasvir price is based on the cost to France’s ATU program, which is €35,000 (US$47,974.52) per patient, regardless of dose (Source: www.seronet.info/article/traiter-lhepatite-c-sans-interferon-des-atu-pour-le-simeprevir-et-le-daclatasvir-66334; accessed on May 3, 2014).

HIV: Not Special, Anymore

People with HIV and hepatitis C (especially genotype 1) are less likely to be cured by peginterferon and ribavirin treatment. In the DAA era, HIV is no longer a poor prognostic factor for response to HCV treatment. Adding a protease inhibitor to PEG-IFN and RBV has produced similar SVR rates, regardless of HIV status.33,34,35,36

Now, proof of concept has been established for efficacy of peginterferon-free regimens in people with HIV and HCV (see table 4). In fact, cure rates from some of the clinical trials in HIV/HCV have been higher than those in HCV monoinfection, probably due to experience with, and support for, adherence to antiretroviral therapy.

Table 4. SVR from Interferon-Free Trials in HIV/HCV15,37,38

Trial (N, regimen, population, phase, sponsor)

Treatment arm

SVR

Comments

ARVs allowed

PHOTON-1
Sofosbuvir + RBV

N = 182

HCV genotype 1 ,2, & 3, Tx-naive,
cirrhosis: 6% (12/182)

Phase II

Gilead

24 weeks, 2 drugs (G1)

SVR-12: 76% (87/114)

Less effective in IL28B non-CC genotypes, Black (vs. non-Black) participants, people with cirrhosis, males, and G1b

atazanavir/r, efavirenz, emtricitabine, darunavir/r, raltegravir, rilpivirine, tenofovir

 

12 weeks, 2 drugs (G2)

SVR-12: 88% (23/26)

12 weeks, 2 drugs (G3)

SVR-12: 67% (28/42)

C-WORTHY
MK-5172 + MK-8742 ± RBV

N = 59

HCV genotype 1, Tx-naive, noncirrhotic

Phase II

Merck

12 weeks, 2 drugs

SVR-12: 90% (26/29)

1 relapse in RBV arm; 2 virologic breakthrough in no-RBV arm; all were in G1a

abacavir, emtricitabine, raltegravir, tenofovir

12 weeks, 3 drugs

SVR-12: 97% (28/29)

ERADICATE

FDC: Sofosbuvir/

ledipasvir

N = 50

HCV genotype 1, Tx-naive, noncirrhotic

Phase II

Interim Data

12 weeks, 2 drugs

ARV-treated, on current regimen for ≥8 weeks, CD4 >100/mm3; HIV RNA <40 copies/mL

SVR-4: 100% (22/22)

 

efavirenz, emtricitabine, raltegravir, rilpivirine, tenofovir

12 weeks, 2 drugs

no ARVs, stable CD4 with HIV RNA <500 copies/mL or CD4 >500/mm3

SVR-4: 100% (10/10)

The only consideration for treating people coinfected with HIV and HCV is avoiding—or managing—drug-drug interactions between DAAs and antiretrovirals (ARVs). To date, the only pangenotypic DAA-based regimen that can be used without restrictions with ARVs (except AZT and ddI which are contraindicated with ribavirin) is 12 weeks of sofosbuvir, peginterferon, and ribavirin.

As of mid-2014, several trials are open or planned in people with HIV/HCV.

Table 5. Ongoing and Planned Trials in HIV/HCV Coinfection

Regimen, sponsor, phase

Population

TURQUOISE-I
ABT-450/r/ABT-267 + ABT-333 + RBV

AbbVie

Phase III

Genotype 1, treatment-naive and treatment-experienced (+ PEG-IFN/RBV)

SWIFT-C
Sofosbuvir + RBV

AIDS Clinical Trials Group

Phase I

Acute HCV infection (or reinfection); genotype not specified

Asunaprevir + daclatasvir

BMS

Phase II

Genotype 1b, treatment-naive and treatment-experienced (+ PEG-IFN/RBV);
no ARV or raltegravir + tenofovir/emtricitabine or abacavir/lamivudine

ALLY-2
Daclatasvir + sofosbuvir

BMS

Phase III

Genotypes 1–6: treatment-naive and treatment-experienced

FDC: Sofosbuvir/ledipasvir

Gilead

Phase II

Genotype 1, treatment-naive

FDC: Sofosbuvir/ledipasvir

or sofosbuvir + RBV

Gilead

Phase II

Genotypes 1, 4 (FDC) and genotypes 2, 3 (sofosbuvir + RBV);
treatment-naive or treatment experienced (+ PEG-IFN/RBV);
inherited bleeding disorder

FDC: Sofosbuvir/ledipasvir

Gilead

Phase II

Genotype 1, treatment-experienced (PEG-IFN/RBV + HCV protease inhibitor)

Sofosbuvir + RBV

Gilead

Phase III

Genotype 1-4 treatment-naive

Genotype 2 and 3, treatment-experienced

FDC: Sofosbuvir/ledipasvir

Gilead

Phase III

Genotype 1 and 4, treatment-naive and treatment-experienced (+ RBV)

C-EDGE COINFECTION
MK-5123 + MK-8742

Merck

Phase III

Genotype 1, 4, 5, and 6; treatment-naive

Source: www.clinicaltrials.gov.

Hepatitis C Trials: Not Just for Middle-Aged, Non-Cirrhotic White Males?

A majority of the participants in HCV clinical trials are middle-aged white males. Enrollment of people from other racial and ethnic groups is shamefully inadequate. There are no data on participation in, or outcomes from, HCV clinical trials among Native Americans and Alaska Natives, although they share the highest incidence of, and mortality from, HCV in the United States.39

African Americans

Information about how DAAs perform in the people most likely to use them is critical, yet it often is unavailable until postmarketing studies have been completed. African Americans are underrepresented in clinical trials, despite high HCV prevalence (22% of cases in the U.S.).40 Enrollment of African Americans hovers below 20 percent in all but one industry-sponsored trial, Gilead’s PHOTON.Hepatitis C infection is more likely to become chronic, and peginterferon-based treatment is less effective for people with the IL28B TT genotype and other genetic polymorphisms found more frequently among African Americans than people of other races and ethnicities.41 African Americans with HCV have poor posttransplant survival rates, and significantly higher incidence of, and mortality from liver cancer than their white counterparts.42,43

Hispanics

Hispanics are twice as likely to die from viral hepatitis than non-Hispanic Whites.44 HCV progresses more rapidly in Hispanics than African Americans or Whites, and they are more likely to develop cirrhosis.45 Type 2 diabetes (which is associated with poor response to peginterferon) is prevalent among Hispanics, underscoring the need for more effective HCV treatment, yet they are often underrepresented in clinical trials.

Women

Although HCV trials enroll a substantial proportion of women, sponsors fail to break out race and ethnicity data by gender, obscuring possible differences in efficacy. Sex- and age-specific side effects are not well characterized in HCV clinical trials, leaving women without adequate information to inform their HCV treatment decisions.

Table 6. Participation in HCV Clinical Trials by Gender, Race, and Ethnicity; Genotype 113,15,16,33,34,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64

Trial: N, Population, and Phase

Women

African American/
Black

Hispanic/

Latino/Latina

Asian

Other

Sponsor: ABBVIE

PEARL-II (N = 186)

G1b only; Tx-experienced, noncirrhotic

Phase III

45% (84/186)

91% (170/186) white; no other race/ethnicity reported

 

 

 

PEARL-III (N = 419)

G1b only; Tx-naive, noncirrhotic

Phase III

56.5% (237/419)

5% (20/419)

1.5% (7/419)

6.5% (28/419)

 

PEARL-IV (N = 305)

G1a only; Tx-naive, noncirrhotic

Phase III

35%(106/305)

12% (36/305)

9% (28/305)

 

4% (12/305)

SAPPHIRE-I (N = 631)

Tx-naive, noncirrhotic

Phase III

45.5% (287/631)

5.5% (34/631)

5% (32/631)

 

 

SAPPHIRE-II (N = 394)

Tx-experienced, noncirrhotic

Phase III

42% (167/394)

8% (32/394)

6% (25/394)

1.5% (6/394)

 

TURQUOISE-II (N = 380)

Tx-naive and Tx-experienced; compensated cirrhosis

Phase III

30% (113/380)

3% (12/380)

12% (45/380)

2% (8/380)

 

Sponsor: BMS

AI444040 (N = 167)

G1a only; Tx-naive and Tx-experienced,
noncirrhotic

Phase II

47% (78/167)

14% (24/167)

 

 

4% (6/167)

A1443-014 (N = 166)

Tx-naive; 9%; cirrhosis

Phase II

33% (54/166)

16% (27/166)

 

1% (2/166)

 

HALLMARK DUAL (N = 745)

G1b only; Tx-naive and Tx-experienced; 30% cirrhosis

Phase III

55% (411/745)

6% (42/745)

 

25% (186/745)

 

Sponsor: BOEHRINGER INGELHEIM

STARTVerso 1 and 2 (N = 1,309)

Tx-naive; 9% cirrhosis

Phase III

44% (578/1309)

7% (94/1309)

 

 

 

 

STARTVerso 3 (N = 678)

Tx-experienced; 21% cirrhosis

Phase III

42% (275/678)

<4% (24/678)

 

 

18% (124/678)

 

 

STARTVerso 4 (N = 308)

HIV-positive, Tx-naive or relapse;
17% cirrhosis

Phase III

19% (60/308)

14% (42/308)

 

2% (7/308)

1% (3/308)

Sponsor: GILEAD

NEUTRINO (N = 327)

G1 (N = 292); Tx-naive; 17% cirrhosis

Phase III

36% (118/327)

 

17% (54/327)

14% (46/327)

2% (7/327)

3% (9/327)

ION-1 (N = 865)

Tx-naive; 16% cirrhosis

Phase III

40.5% (352/865)

12.5% (108/865)

 

12% (101/865)

<2% (11/865)

<2% (11/865)

ION-2 (N = 440)

Tx- experienced; 20% cirrhosis

Phase III

35% (153/440)

17% (77/440)

9% (41/440)

<0.5% (1/440)

<1% (2 other, one Hawaiian/ Asian Pacific Islander)

ION-3 (N = 647)

Tx-naive; noncirrhotic

Phase III

42% (272/647)

 

19% (123/647)

 

6% (39/647)

 

2.5% (17/647)

 

PHOTON-1 (N = 114)

HIV-positive, Tx-naive;

4% cirrhosis

Phase III

18% (21/114)

33% (37/114)

22% (25/114)

 

 

Sponsor: JANSSEN

C0212 (N = 106)

HIV-positive; Tx naive and
tx-experienced; 10% cirrhosis

Phase II

15% (16/106)

14% (14/106)

 

 

 

COSMOS (N = 167)

Tx-naive and Tx-experienced;
40% cirrhosis

Phase II

36% (60/167)

 

19% (31/167)

 

21% (35/167)

 

 

 

PROMISE (N = 393)

Relapsers; 15% cirrhosis

Phase III

34% (133/393)

3% (13/393)

6% (24/393)

3% (11/393)

1% (1 Asian Pacific Islander; 1 mixed-race)

QUEST-1 (N = 394)

Tx-naive; 12% cirrhosis

Phase III

43.5%(172/394)

8% (30/393)

 

2% (7/393)

 

QUEST-2 (N = 391)

Tx-naive; 8% cirrhosis

Phase III

44% (171/391)

91.5% (329/ 360) white; no other race/ethnicity reported

 

 

 

Sponsor: MERCK

C-WORTHY (N = 159)
Tx-naive; noncirrhotic
Phase II

50% (78/159)

7% (11/159)

10% (15/159)

<3% (4/159)

 

C-WORTHY (N = 253)

Tx-naive and null responders; 40% cirrhosis

Phase II

41% (105/253)

6% (15/253)

5% (12/253)

 

2% (5/253)

Sponsor: NIAID

SPARE (N = 60)

Tx-naive; 22% precirrhosis or cirrhosis

Phase II

38% (23/60)

83% (50/60)

4% (2/60)

 

 

SYNERGY (N = 60)

Tx-naive; 5% cirrhosis

Phase II

29% (17/60)

89% (53/60)

 

 

 

ADVERSE EVENTS

The expression “generally well tolerated” is used to describe virtually any adverse event (AE) that doesn’t kill participants in HCV clinical trials. AE reports from DAA trials tend to be overshadowed by the astonishing cure rates and ever-shorter treatment durations. Years of looking at long, long lists of AEs and high discontinuation rates from trials of peginterferon and ribavirin-based regimens have numbed conference attendees (who are also not the ones experiencing them). But these adverse events are likely to be worse in the real world, given that people in clinical trials are usually healthier, monitored more closely, and cared for by more experienced clinicians.

In phase II and phase III trials of DAAs, at least five percent of study participants experienced an adverse event (see table 7). Adverse events are not always reported in terms of severity and duration, and it is unclear how many people are bedeviled by multiple AEs.

Ribavirin the Terrible

Although peginterferon is quickly becoming a therapeutic relic, ribavirin is still in the mix. It may be more toxic than anyone realized. Some of the AEs associated with peginterferon (irritability, anxiety, depression, insomnia, nausea, muscle and joint pain) have now been reported in ribavirin-containing arms of peginterferon-free trials.

Even without ribavirin, it is difficult to identify which drug or drugs are the culprits, since DAAs are not used alone.

Table 7. Adverse Events in ≥5 Percent of Participants, from a Sampling ofbPhase II and Phase III DAA Trials (Alphabetical Order)15,18,27,28,30,49,50,57,63,65,66,67

 

Treatment-Naive

Treatment-Experienced

RBV-free

 

Abdominal distention, abdominal pain, anxiety, asthenia, back pain, common cold, constipation, cough, diarrhea, dizziness, dysmenorrhea, dyspepsia, nasopharyngitis, night sweats, fatigue, headache, insomnia, irritability, nausea, oropharyngeal pain, pain, pruritus, rash, shoulder pain, upper abdominal pain, vomiting

Abdominal distention, anxiety, arthralgia, back pain, constipation, cough, diarrhea, dizziness, dry skin, dysmenorrhea, dyspepsia, fatigue, headache, insomnia, irritability, nasopharyngitis, nausea, oropharyngeal pain, pain, pruritus, rash, upper abdominal pain, vomiting

RBV-containing

Anemia, arthralgia, asthenia, back pain, decreased appetite, diarrhea, dizziness, dyspepsia, fatigue, headache, insomnia, irritability, myalgia, nausea, pruritus, pyrexia, rash, upper respiratory tract infection

Anemia, arthralgia, asthenia, cough, depression, diarrhea, dizziness, fatigue, headache, insomnia, irritability, nausea, pain, pruritus, rash, upper respiratory tract infection

People Who Inject Drugs

In the developed world, 80 percent of new HCV infections occur in people who inject drugs (PWID), due to lack of access to sterile injection equipment.68 Worldwide, 10 to 15 million PWID have been infected with hepatitis C virus.69 Yet only two to four percent of PWID have been treated, due to a range of structural, socioeconomic, cultural, legal, and other barriers.70 Concerns about poor adherence lead some physicians to withhold treatment from PWID, regardless of evidence that adherence and HCV treatment outcomes among people who inject drugs are similar to those among people who are not injecting drugs.71


From TasP to CasP

I don’t want to be called a transmitter—that’s electricity.
—Jude Byrne, Senior Project Officer, National Hepatitis C and Other BBVs/STIs Program, Australian Injecting & Illicit Drug Users League (AIVL)

Research on HIV treatment as prevention (TasP) has inspired modelers to look at the impact of HCV treatment on prevalence among people who inject drugs. Unlike HIV, hepatitis C can be cured; only a few months of oral drugs are needed to accomplish this. Mathematical models indicate that treating a small proportion of PWID will significantly reduce HCV prevalence, given the high SVR rates seen in DAA clinical trials.72

HCV cure as prevention (CasP) is an advocacy platform for ramping up access to both HCV prevention and treatment for PWID. But barriers such as criminalization and discrimination will stymie efforts to implement CasP among PWID. It is critical that people who inject drugs be involved in the design, implementation, and oversight of CasP programs, and that these programs be linked to larger social justice movements.


Pregnancy and Pediatrics

Each year, 60,000 infants are born with HCV infection. In HCV-monoinfected women, the rate of vertical transmission is three to five percent; HIV coinfection doubles the risk.73,74 It may be possible to prevent vertical transmission with ribavirin-free DAA regimens, but there have not been any trials so far.

The standard of care for children from 3 to 17 years of age is peginterferon and ribavirin, which has many side effects and may inhibit growth.75 Earlier HCV regimens were not ideal for use in pediatrics (or adults). Newer DAA regimens should be studied in pediatrics.

CONCLUSION

Although the HIV experience is valuable for tackling HCV, there are significant differences between these viruses and responses to them. HIV activists have mobilized worldwide using a human rights–based framework, wielding evidence from global research networks to fight for programs that prevent, diagnose, and treat HIV. In contrast, the dialogue about HCV has been primarily focused on cost-effectiveness, due to high prices and flaccid responses from governments and donors.

The hard work—transforming the HCV treatment cascade from scarcely a dribble into a waterfall—is just beginning. Access to affordable HCV viral-load testing and treatment can become a reality, so long as people are willing to fight for them.

The lessons learned from AIDS treatment activism and scale-up are relevant to hepatitis C: drugs cannot stop an epidemic by themselves, no matter how good they are. Activists, donors, governments, implementers, and clinicians must work together to make sure that HCV treatment reaches all who need it.

RECOMMENDATIONS

Research

  • Support public-private research partnerships for HCV diagnostics and treatment; leaving drug development solely to the pharmaceutical industry does not serve public health, and may be hazardous.
     
  • Focus on development of HCV diagnostics for resource-limited settings, using the WHO ASSURED criteria; pilot HCV treatment projects are opportunities to simultaneously validate innovative HCV diagnostics.
     
  • Identify and study the best DAAs for preventing vertical transmission.
     
  • Launch pediatric trials in HCV and HIV/HCV coinfection (with the most suitable candidates).
     
  • Study DAA regimens in people with HCV genotypes 5 and 6.
     
  • Develop DAAs in different formulations (long-acting, single-injection) to facilitate HCV treatment scale-up.
     
  • Enroll representative populations in HCV clinical trials, especially people with advanced liver disease from high-prevalence populations.

Policy and Implementation

  • Governments must not continue to ignore HCV; it is time for national plans to address the epidemic. People with HCV and their allies, people who inject drugs, epidemiologists, medical providers, researchers, and policy makers need to participate in development and implementation of their national plans.
     
  • Donors need to support and coordinate efforts to increase global access to HCV prevention, diagnostics, care, and treatment in LMICs.
     
  • Pharmaceutical companies must allow generic competition, since they have ample opportunity to recoup investment in, and amply profit from their DAAs.
     
  • Implementers must gear up; it is time to initiate widespread capacity building so that nonspecialist providers, community health care workers, and peers can deliver HCV education, screening, care, and treatment.
     
  • People who inject drugs must have the opportunity to participate in the design, implementation, and oversight of HCV prevention, testing, and treatment programs intended for them.

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ENDNOTES

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