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2014年1月20日，丙肝新药Sovaldi（sofosbuvir，400mg片剂）获欧盟批准，作为抗病毒治疗方案的一部分，用于慢性丙型肝炎（HCV）成人感染者的治疗。Sovaldi为每日一次的口服核苷类似物聚合酶抑制剂，此次批准，为该药在整个欧盟的上市铺平了道路。
a. For previously treated patients with HCV genotype 1 infection, no data exists with the combination of Sovaldi, ribavirin and peginterferon alfa (see section 4.4). b. Consideration should be given to potentially extending the duration of therapy beyond 12 weeks and up to 24 weeks; especially for those subgroups who have one or more factors historically associated with lower response rates to interferon-based therapies (e.g. advanced fibrosis/cirrhosis, high baseline viral concentrations, black race, IL28B non CC genotype, prior null response to peginterferon alfa and ribavirin therapy). c. See Special patient populations – Patients awaiting liver transplantation below. The dose of ribavirin, when used in combination with Sovaldi, is weight-based (<75 kg = 1,000 mg and ≥75 kg = 1,200 mg) and administered orally in two divided doses with food. Concerning co-administration with other direct-acting antivirals against HCV, see section 4.4. Dose modification Dose reduction of Sovaldi is not recommended. If sofosbuvir is used in combination with peginterferon alfa, and a patient has a serious adverse reaction potentially related to this drug, the peginterferon alfa dose should be reduced or discontinued. Refer to the peginterferon alfa Summary of Product Characteristics for additional information about how to reduce and/or discontinue the peginterferon alfa dose. If a patient has a serious adverse reaction potentially related to ribavirin, the ribavirin dose should be modified or discontinued, if appropriate, until the adverse reaction abates or decreases in severity. Table 2 provides guidelines for dose modifications and discontinuation based on the patient's haemoglobin concentration and cardiac status. Table 2: Ribavirin dose modification guideline for co-administration with Sovaldi
Discontinuation of dosing If the other medicinal products used in combination with Sovaldi are permanently discontinued, Sovaldi should also be discontinued (see section 4.4). Special patient populations Elderly No dose adjustment is warranted for elderly patients (see section 5.2). Renal impairment No dose adjustment of Sovaldi is required for patients with mild or moderate renal impairment. The safety and appropriate dose of Sovaldi have not been established in patients with severe renal impairment (estimated glomerular filtration rate [eGFR] <30 mL/min/1.73 m2) or end stage renal disease (ESRD) requiring haemodialysis (see section 5.2). Hepatic impairment No dose adjustment of Sovaldi is required for patients with mild, moderate or severe hepatic impairment (Child-Pugh-Turcotte [CPT] class A, B or C) (see section 5.2). The safety and efficacy of Sovaldi have not been established in patients with decompensated cirrhosis. Patients awaiting liver transplantation The duration of administration of Sovaldi in patients awaiting liver transplantation should be guided by an assessment of the potential benefits and risks for the individual patient (see section 5.1). Paediatric population The safety and efficacy of Sovaldi in children and adolescents aged <18 years have not yet been established. No data are available. Method of administration The film-coated tablet is for oral use. Patients should be instructed to swallow the tablet whole. The film-coated tablet should not be chewed or crushed, due to the bitter taste of the active substance. The tablet should be taken with food (see section 5.2). Patients should be instructed that if vomiting occurs within 2 hours of dosing an additional tablet should be taken. If vomiting occurs more than 2 hours after dosing, no further dose is needed. These recommendations are based on the absorption kinetics of sofosbuvir and GS-331007 suggesting that the majority of the dose is absorbed within 2 hours after dosing. If a dose is missed and it is within 18 hours of the normal time, patients should be instructed to take the tablet as soon as possible and then patients should take the next dose at the usual time. If it is after 18 hours then patients should be instructed to wait and take the next dose at the usual time. Patients should be instructed not to take a double dose. 4.3 Contraindications Hypersensitivity to the active substance or to any of the excipients listed in section 6.1. 4.4 Special warnings and precautions for use General Sovaldi is not recommended for administration as monotherapy and should be prescribed in combination with other medicinal products for the treatment of hepatitis C infection. If the other medicinal products used in combination with Sovaldi are permanently discontinued, Sovaldi should also be discontinued (see section 4.2). Consult the Summary of Product Characteristics for co-prescribed medicinal products before starting therapy with Sovaldi. Treatment-experienced patients with genotype 1, 4, 5 and 6 HCV infection Sovaldi has not been studied in a Phase 3 study in treatment-experienced patients with genotype 1, 4, 5 and 6 HCV infection. Thus, the optimal treatment duration in this population has not been established (see also sections 4.2 and 5.1). Consideration should be given to treating these patients, and potentially extending the duration of therapy with sofosbuvir, peginterferon alfa and ribavirin beyond 12 weeks and up to 24 weeks; especially for those subgroups who have one or more factors historically associated with lower response rates to interferon-based therapies (advanced fibrosis/cirrhosis, high baseline viral concentrations, black race, IL28B non CC genotype). Treatment of patients with genotype 5 or 6 HCV infection The clinical data to support the use of Sovaldi in patients with genotype 5 and 6 HCV infection is very limited (see section 5.1). Interferon-free therapy for genotype 1, 4, 5 and 6 HCV infection Interferon-free regimens for patients with genotype 1, 4, 5 and 6 HCV infection with Sovaldi have not been investigated in Phase 3 studies (see section 5.1). The optimal regimen and treatment duration have not been established. Such regimens should only be used for patients that are intolerant to or ineligible for interferon therapy, and are in urgent need of treatment. Co-administration with other direct-acting antivirals against HCV Sovaldi should only be co-administered with other direct-acting antiviral medicinal products if the benefit is considered to outweigh the risks based upon available data. There are no data to support the co-administration of Sovaldi and telaprevir or boceprevir. Such co-administration is not recommended (see also section 4.5). Pregnancy and concomitant use with ribavirin When Sovaldi is used in combination with ribavirin or peginterferon alfa/ribavirin, women of childbearing potential or their male partners must use an effective form of contraception during the treatment and for a period of time after the treatment as recommended in the Summary of Product Characteristics for ribavirin. Refer to the Summary of Product Characteristics for ribavirin for additional information. Use with potent P-gp inducers Medicinal products that are potent P-glycoprotein (P-gp) inducers in the intestine (e.g. rifampicin, St. John's wort [Hypericum perforatum], carbamazepine and phenytoin) may significantly decrease sofosbuvir plasma concentration leading to reduced therapeutic effect of Sovaldi. Such medicinal products should not be used with Sovaldi (see section 4.5). Renal impairment The safety of Sovaldi has not been assessed in subjects with severe renal impairment (eGFR <30 mL/min/1.73 m2) or ESRD requiring haemodialysis. Furthermore, the appropriate dose has not been established. When Sovaldi is used in combination with ribavirin or peginterferon alfa/ribavirin, refer also to the Summary of Product Characteristics for ribavirin for patients with creatinine clearance (CrCl) <50 mL/min (see also section 5.2). HCV/HBV (hepatitis B virus) co-infection There are no data on the use of Sovaldi in patients with HCV/HBV co-infection. Paediatric population Sovaldi is not recommended for use in children and adolescents under 18 years of age because the safety and efficacy have not been established in this population. 4.5 Interaction with other medicinal products and other forms of interaction Sofosbuvir is a nucleotide prodrug. After oral administration of Sovaldi, sofosbuvir is rapidly absorbed and subject to extensive first-pass hepatic and intestinal metabolism. Intracellular hydrolytic prodrug cleavage catalysed by enzymes including carboxylesterase 1 and sequential phosphorylation steps catalysed by nucleotide kinases result in formation of the pharmacologically active uridine nucleoside analogue triphosphate. The predominant inactive circulating metabolite GS-331007 that accounts for greater than 90% of drug-related material systemic exposure is formed through pathways sequential and parallel to formation of active metabolite. The parent sofosbuvir accounts for approximately 4% of drug-related material systemic exposure (see section 5.2). In clinical pharmacology studies, both sofosbuvir and GS-331007 were monitored for purposes of pharmacokinetic analyses. Sofosbuvir is a substrate of drug transporter P-gp and breast cancer resistance protein (BCRP) while GS-331007 is not. Medicinal products that are potent P-gp inducers in the intestine (e.g. rifampicin, St. John's wort, carbamazepine and phenytoin) may decrease sofosbuvir plasma concentration leading to reduced therapeutic effect of Sovaldi and thus should not be used with Sovaldi (see section 4.4). Co-administration of Sovaldi with medicinal products that inhibit P-gp and/or BCRP may increase sofosbuvir plasma concentration without increasing GS-331007 plasma concentration, thus Sovaldi may be co-administered with P-gp and/or BCRP inhibitors. Sofosbuvir and GS-331007 are not inhibitors of P-gp and BCRP and thus are not expected to increase exposures of medicinal products that are substrates of these transporters. The intracellular metabolic activation pathway of sofosbuvir is mediated by generally low affinity and high capacity hydrolase and nucleotide phosphorylation pathways that are unlikely to be affected by concomitant medicinal products (see section 5.2). Other interactions Drug interaction information for Sovaldi with potential concomitant medicinal products is summarised in Table 3 below (where 90% confidence interval (CI) of the geometric least-squares mean (GLSM) ratio were within “↔”, extended above “↑”, or extended below “↓” the predetermined equivalence boundaries). The table is not all-inclusive. Table 3: Interactions between Sovaldi and other medicinal products
a. Mean ratio (90% CI) of co-administered drug pharmacokinetics with/without sofosbuvir and mean ratio of sofosbuvir and GS-331007 with/without co-administered drug. No effect = 1.00 b. All interaction studies conducted in healthy volunteers c. Comparison based on historical control d. Administered as Atripla e. Bioequivalence boundary 80%-125% f. Equivalence boundary 70%-143% Medicinal products that are potent P-gp inducers in the intestine (rifampicin, St. John's wort, carbamazepine and phenytoin) may significantly decrease sofosbuvir plasma concentration leading to reduced therapeutic effect. For this reason, sofosbuvir should not be co-administered with known inducers of P-gp. 4.6 Fertility, pregnancy and lactation Women of childbearing potential / contraception in males and females When Sovaldi is used in combination with ribavirin or peginterferon alfa/ribavirin, extreme care must be taken to avoid pregnancy in female patients and in female partners of male patients. Significant teratogenic and/or embryocidal effects have been demonstrated in all animal species exposed to ribavirin (see section 4.4). Women of childbearing potential or their male partners must use an effective form of contraception during treatment and for a period of time after the treatment has concluded as recommended in the Summary of Product Characteristics for ribavirin. Refer to the Summary of Product Characteristics for ribavirin for additional information. Pregnancy There are no or limited amount of data (less than 300 pregnancy outcomes) from the use of sofosbuvir in pregnant women. Animal studies do not indicate direct or indirect harmful effects with respect to reproductive toxicity. No effects on foetal development have been observed in rats and rabbits at the highest doses tested. However, it has not been possible to fully estimate exposure margins achieved for sofosbuvir in the rat relative to the exposure in humans at the recommended clinical dose (see section 5.3). As a precautionary measure, it is preferable to avoid the use of Sovaldi during pregnancy. However, if ribavirin is co-administered with sofosbuvir, the contraindications regarding use of ribavirin during pregnancy apply (see also the Summary of Product Characteristics for ribavirin). Breast-feeding It is unknown whether sofosbuvir and its metabolites are excreted in human milk. Available pharmacokinetic data in animals has shown excretion of metabolites in milk (for details see section 5.3). A risk to newborns/infants cannot be excluded. Therefore, Sovaldi should not be used during breast-feeding. Fertility No human data on the effect of Sovaldi on fertility are available. Animal studies do not indicate harmful effects on fertility. 4.7 Effects on ability to drive and use machines Sovaldi has moderate influence on the ability to drive and use machines. Patients should be informed that fatigue and disturbance in attention, dizziness and blurred vision have been reported during treatment with sofosbuvir in combination with peginterferon alfa and ribavirin (see section 4.8). 4.8 Undesirable effects Summary of the safety profile During treatment with sofosbuvir in combination with ribavirin or with peginterferon alfa and ribavirin, the most frequently reported adverse drug reactions were consistent with the expected safety profile of ribavirin and peginterferon alfa treatment, without increasing the frequency or severity of the expected adverse drug reactions. Assessment of adverse reactions is based on pooled data from five Phase 3 clinical studies (both controlled and uncontrolled). The proportion of subjects who permanently discontinued treatment due to adverse reactions was 1.4% for subjects receiving placebo, 0.5% for subjects receiving sofosbuvir + ribavirin for 12 weeks, 0% for subjects receiving sofosbuvir + ribavirin for 16 weeks, 11.1% for subjects receiving peginterferon alfa + ribavirin for 24 weeks and 2.4% for subjects receiving sofosbuvir + peginterferon alfa + ribavirin for 12 weeks. Tabulated summary of adverse reactions Sovaldi has mainly been studied in combination with ribavirin, with or without peginterferon alfa. In this context, no adverse drug reactions specific to sofosbuvir have been identified. The most common adverse drug reactions occurring in subjects receiving sofosbuvir and ribavirin or sofosbuvir, ribavirin and peginterferon alfa were fatigue, headache, nausea and insomnia. The following adverse drug reactions have been identified with sofosbuvir in combination with ribavirin or in combination with peginterferon alfa and ribavirin (Table 4). The adverse reactions are listed below by body system organ class and frequency. Frequencies are defined as follows: very common (≥1/10), common (≥1/100 to <1/10), uncommon (≥1/1,000 to <1/100), rare (≥1/10,000 to <1/1,000) or very rare (<1/10,000). Table 4: Adverse drug reactions identified with sofosbuvir in combination with ribavirin or peginterferon alfa and ribavirin
Other special population(s) HIV/HCV co-infection The safety profile of sofosbuvir and ribavirin in HCV/HIV co-infected subjects was similar to that observed in mono-infected HCV subjects treated with sofosbuvir and ribavirin in Phase 3 clinical studies (see section 5.1). Patients awaiting liver transplantation The safety profile of sofosbuvir and ribavirin in HCV infected subjects prior to liver transplantation was similar to that observed in subjects treated with sofosbuvir and ribavirin in Phase 3 clinical studies (see section 5.1). Reporting of suspected adverse reactions Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via the national reporting system: United Kingdom Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard Ireland Pharmacovigilance Section Irish Medicines Board Kevin O'Malley House Earlsfort Centre Earlsfort Terrace IRL - Dublin 2 Tel: +353 1 6764971 Fax: +353 1 6762517 Website: www.imb.ie e-mail: imbpharmacovigilance@imb.ie Malta ADR Reporting The Medicines Authority Post-Licensing Directorate 203 Level 3, Rue D'Argens GŻR -1368 Gżira Website: www.medicinesauthority.gov.mt e-mail: postlicensing.medicinesauthority@gov.mt 4.9 Overdose The highest documented dose of sofosbuvir was a single supratherapeutic dose of sofosbuvir 1,200 mg administered to 59 healthy subjects. In that study, there were no untoward effects observed at this dose level, and adverse reactions were similar in frequency and severity to those reported in the placebo and sofosbuvir 400 mg treatment groups. The effects of higher doses are unknown. No specific antidote is available for overdose with Sovaldi. If overdose occurs the patient must be monitored for evidence of toxicity. Treatment of overdose with Sovaldi consists of general supportive measures including monitoring of vital signs as well as observation of the clinical status of the patient. Haemodialysis can efficiently remove (53% extraction ratio) the predominant circulating metabolite GS-331007. A 4-hour haemodialysis session removed 18% of the administered dose. 5. Pharmacological properties 5.1 Pharmacodynamic properties Pharmacotherapeutic group: Direct-acting antiviral; ATC code: not yet assigned Mechanism of action Sofosbuvir is a pan-genotypic inhibitor of the HCV NS5B RNA-dependent RNA polymerase, which is essential for viral replication. Sofosbuvir is a nucleotide prodrug that undergoes intracellular metabolism to form the pharmacologically active uridine analog triphosphate (GS-461203), which can be incorporated into HCV RNA by the NS5B polymerase and acts as a chain terminator. In a biochemical assay, GS-461203 inhibited the polymerase activity of the recombinant NS5B from HCV genotype 1b, 2a, 3a and 4a with a 50% inhibitory concentration (IC50) value ranging from 0.7 to 2.6 μM. GS-461203 (the active metabolite of sofosbuvir) is not an inhibitor of human DNA and RNA polymerases nor an inhibitor of mitochondrial RNA polymerase. Antiviral activity In HCV replicon assays, the effective concentration (EC50) values of sofosbuvir against full-length replicons from genotype 1a, 1b, 2a, 3a and 4a were 0.04, 0.11, 0.05, 0.05 and 0.04 μM, respectively, and EC50 values of sofosbuvir against chimeric 1b replicons encoding NS5B from genotype 2b, 5a or 6a were 0.014 to 0.015 μM. The mean ± SD EC50 of sofosbuvir against chimeric replicons encoding NS5B sequences from clinical isolates was 0.068 ± 0.024 μM for genotype 1a (n = 67), 0.11 ± 0.029 μM for genotype 1b (n = 29), 0.035 ± 0.018 μM for genotype 2 (n = 15) and 0.085 ± 0.034 μM for genotype 3a (n = 106). In these assays, the in vitro antiviral activity of sofosbuvir against the less common genotypes 4, 5 and 6 was similar to that observed for genotypes 1, 2 and 3. The presence of 40% human serum had no effect on the anti-HCV activity of sofosbuvir. Resistance In cell culture HCV replicons with reduced susceptibility to sofosbuvir have been selected in cell culture for multiple genotypes including 1b, 2a, 2b, 3a, 4a, 5a and 6a. Reduced susceptibility to sofosbuvir was associated with the primary NS5B substitution S282T in all replicon genotypes examined. Site-directed mutagenesis of the S282T substitution in replicons of 8 genotypes conferred 2- to 18-fold reduced susceptibility to sofosbuvir and reduced the replication viral capacity by 89% to 99% compared to the corresponding wild-type. In biochemical assays, recombinant NS5B polymerase from genotypes 1b, 2a, 3a and 4a expressing the S282T substitution showed reduced susceptibility to GS-461203 compared to respective wild-types. In clinical studies In a pooled analysis of 991 subjects who received sofosbuvir in Phase 3 studies, 226 subjects qualified for resistance analysis due to virologic failure or early study drug discontinuation and having HCV RNA >1,000 IU/mL. Post-baseline NS5B sequences were available for 225 of the 226 subjects, with deep sequencing data (assay cutoff of 1%) from 221 of these subjects. The sofosbuvir-associated resistance substitution S282T was not detected in any of these subjects by deep sequencing or population sequencing. The S282T substitution in NS5B was detected in a single subject receiving Sovaldi monotherapy in a Phase 2 study. This subject harboured <1% HCV S282T at baseline and developed S282T (>99%) at 4 weeks post-treatment which resulted in a 13.5-fold change in sofosbuvir EC50 and reduced viral replication capacity. The S282T substitution reverted to wild-type over the next 8 weeks and was no longer detectable by deep sequencing at 12 weeks post-treatment. Two NS5B substitutions, L159F and V321A, were detected in post-treatment relapse samples from multiple genotype 3 HCV infected subjects in the Phase 3 clinical studies. No shift in the phenotypic susceptibility to sofosbuvir or ribavirin of subject isolates with these substitutions was detected. In addition, S282R and L320F substitutions were detected on treatment by deep sequencing in a pre-transplant subject with a partial treatment response. The clinical significance of these findings is unknown. Effect of baseline HCV polymorphisms on treatment outcome Baseline NS5B sequences were obtained for 1,292 subjects from Phase 3 studies by population sequencing and the S282T substitution was not detected in any subject with available baseline sequence. In an analysis evaluating the effect of baseline polymorphisms on treatment outcome, no statistically significant association was observed between the presence of any HCV NS5B variant at baseline and treatment outcome. Cross-resistance HCV replicons expressing the sofosbuvir-associated resistance substitution S282T were fully susceptible to other classes of anti-HCV agents. Sofosbuvir retained activity against the NS5B substitutions L159F and L320F associated with resistance to other nucleoside inhibitors. Sofosbuvir was fully active against substitutions associated with resistance to other direct-acting antivirals with different mechanisms of actions, such as NS5B non-nucleoside inhibitors, NS3 protease inhibitors and NS5A inhibitors. Clinical efficacy and safety The efficacy of sofosbuvir was evaluated in five Phase 3 studies in a total of 1,568 subjects with genotypes 1 to 6 chronic hepatitis C. One study was conducted in treatment-naïve subjects with genotype 1, 4, 5 or 6 chronic hepatitis C in combination with peginterferon alfa 2a and ribavirin and the other four studies were conducted in subjects with genotype 2 or 3 chronic hepatitis C in combination with ribavirin including one in treatment-naïve subjects, one in interferon intolerant, ineligible or unwilling subjects, one in subjects previously treated with an interferon-based regimen, and one in all subjects irrespective of prior treatment history or ability to receive treatment with interferon. Subjects in these studies had compensated liver disease including cirrhosis. Sofosbuvir was administered at a dose of 400 mg once daily. The ribavirin dose was weight-based at 1,000-1,200 mg daily administered in two divided doses, and the peginterferon alfa 2a dose, where applicable, was 180 μg per week. Treatment duration was fixed in each study and was not guided by subjects' HCV RNA levels (no response guided algorithm). Plasma HCV RNA values were measured during the clinical studies using the COBAS TaqMan HCV test (version 2.0), for use with the High Pure System. The assay had a lower limit of quantification (LLOQ) of 25 IU/mL. Sustained virologic response (SVR) was the primary endpoint to determine the HCV cure rate for all studies which was defined as HCV RNA less than LLOQ at 12 weeks after the end of treatment (SVR12). Clinical studies in subjects with genotype 1, 4, 5 and 6 chronic hepatitis C Treatment-naïve subjects - NEUTRINO (study 110) NEUTRINO was an open-label, single-arm study that evaluated 12 weeks of treatment with sofosbuvir in combination with peginterferon alfa 2a and ribavirin in treatment-naïve subjects with genotype 1, 4, 5 or 6 HCV infection. Treated subjects (n = 327) had a median age of 54 years (range: 19 to 70); 64% of the subjects were male; 79% were White; 17% were Black; 14% were Hispanic or Latino; mean body mass index was 29 kg/m2 (range: 18 to 56 kg/m2); 78% had baseline HCV RNA greater than 6 log10 IU/mL; 17% had cirrhosis; 89% had HCV genotype 1 and 11% had HCV genotype 4, 5 or 6. Table 5 presents the response rates for the treatment group of sofosbuvir + peginterferon alfa + ribavirin. Table 5: Response rates in study NEUTRINO
b. Other includes subjects who did not achieve SVR12 and did not meet virologic failure criteria (e.g., lost to follow-up). Response rates for selected subgroups are presented in Table 6. Table 6: SVR12 rates for selected subgroups in NEUTRINO
B C/C allele [94/95 (99%)] and non-C/C (C/T or T/T) allele [202/232 (87%)].
b. The denominator for relapse is the number of subjects with HCV RNA <LLOQ at their last on-treatment assessment. c. Other includes subjects who did not achieve SVR12 and did not meet virologic failure criteria (e.g., lost to follow-up). The difference in the overall SVR12 rates between sofosbuvir + ribavirin and peginterferon alfa + ribavirin treatment groups was 0.3% (95% confidence interval: -7.5% to 8.0%) and the study met the predefined non-inferiority criterion. Response rates for subjects with cirrhosis at baseline are presented in Table 8 by HCV genotype. Table 8: SVR12 rates by cirrhosis and genotype in study FISSION
Interferon intolerant, ineligible or unwilling adults - POSITRON (study 107) POSITRON was a randomised, double-blinded, placebo-controlled study that evaluated 12 weeks of treatment with sofosbuvir and ribavirin (n = 207) compared to placebo (n = 71) in subjects who are interferon intolerant, ineligible or unwilling. Subjects were randomised in 3:1 ratio and stratified by cirrhosis (presence versus absence). Treated subjects (n = 278) had a median age of 54 years (range: 21 to 75); 54% of the subjects were male; 91% were White; 5% were Black; 11% were Hispanic or Latino; mean body mass index was 28 kg/m2 (range: 18 to 53 kg/m2); 70% had baseline HCV RNA levels greater than 6 log10 IU/mL; 16% had cirrhosis; 49% had HCV genotype 3. The proportions of subjects who were interferon intolerant, ineligible, or unwilling were 9%, 44%, and 47%, respectively. Most subjects had no prior HCV treatment (81.3%). Table 9 presents the response rates for the treatment groups of sofosbuvir + ribavirin and placebo. Table 9: Response rates in study POSITRON
b. Other includes subjects who did not achieve SVR12 and did not meet virologic failure criteria (e.g., lost to follow-up). The SVR12 rate in the sofosbuvir + ribavirin treatment group was statistically significant when compared to placebo (p <0.001). Table 10 presents the subgroup analysis by genotype for cirrhosis and interferon classification. Table 10: SVR12 rates for selected subgroups by genotype in POSITRON
FUSION was a randomised, double-blinded study that evaluated 12 or 16 weeks of treatment with sofosbuvir and ribavirin in subjects who did not achieve SVR with prior interferon-based treatment (relapsers and nonresponders). Subjects were randomised in a 1:1 ratio and stratified by cirrhosis (presence versus absence) and HCV genotype (2 versus 3). Treated subjects (n = 201) had a median age of 56 years (range: 24 to 70); 70% of the subjects were male; 87% were White; 3% were Black; 9% were Hispanic or Latino; mean body mass index was 29 kg/m2 (range: 19 to 44 kg/m2); 73% had baseline HCV RNA levels greater than 6 log10 IU/mL; 34% had cirrhosis; 63% had HCV genotype 3; 75% were prior relapsers. Table 11 presents the response rates for the treatment groups of sofosbuvir + ribavirin for 12 weeks and 16 weeks. Table 11: Response rates in study FUSION
b. The denominator for relapse is the number of subjects with HCV RNA <LLOQ at their last on-treatment assessment. c. Other includes subjects who did not achieve SVR12 and did not meet virologic failure criteria (e.g., lost to follow-up). Table 12 presents the subgroup analysis by genotype for cirrhosis and response to prior HCV treatment. Table 12: SVR12 rates for selected subgroups by genotype in study FUSION
VALENCE was a Phase 3 study that evaluated sofosbuvir in combination with weight-based ribavirin for the treatment of genotype 2 or 3 HCV infection in treatment-naïve subjects or subjects who did not achieve SVR with prior interferon-based treatment, including subjects with compensated cirrhosis. The study was designed as a direct comparison of sofosbuvir and ribavirin versus placebo for 12 weeks. However, based on emerging data, the study was unblinded and all HCV genotype 2 subjects continued to receive sofosbuvir and ribavirin for 12 weeks, whilst treatment for HCV genotype 3 subjects was extended to 24 weeks. Eleven HCV genotype 3 subjects had already completed treatment with sofosbuvir and ribavirin for 12 weeks at the time of the amendment. Treated subjects (n = 419) had a median age of 51 years (range: 19 to 74); 60% of the subjects were male; median body mass index was 25 kg/m2 (range: 17 to 44 kg/m2); the mean baseline HCV RNA level was 6.4 log10 IU/mL; 21% had cirrhosis; 78% had HCV genotype 3; 65% were prior relapsers. Table 13 presents the response rates for the treatment groups of sofosbuvir + ribavirin for 12 weeks and 24 weeks. Placebo recipients are not included in the tables since none achieved SVR12. Table 13: Response rates in study VALENCE
b. Other includes subjects who did not achieve SVR12 and did not meet virologic failure criteria (e.g., lost to follow-up). Table 14 presents the subgroup analysis by genotype for cirrhosis and exposure to prior HCV treatment. Table 14: SVR12 rates for selected subgroups by genotype in study VALENCE
The concordance between SVR12 and SVR24 (SVR 24 weeks after the end of the treatment) following treatment with sofosbuvir in combination with ribavirin or ribavirin and pegylated interferon demonstrates a positive predictive value of 99% and a negative predictive value of 99%. HCV/HIV co-infected patients - PHOTON-1 (study 123) Sofosbuvir was studied in an open-label clinical study evaluating the safety and efficacy of 12 or 24 weeks of treatment with sofosbuvir and ribavirin in subjects with genotype 1, 2 or 3 chronic hepatitis C co-infected with HIV-1. Genotype 2 and 3 subjects were either treatment-naïve or experienced, whereas genotype 1 subjects were naïve to prior treatment. Treatment duration was 12 weeks in treatment-naïve subjects with genotype 2 or 3 HCV infection, and 24 weeks in treatment-experienced subjects with genotype 3 HCV infection, as well as subjects with genotype 1 HCV infection. Subjects received 400 mg sofosbuvir and weight-based ribavirin (1,000 mg for subjects weighing <75 kg or 1,200 mg for subjects weighing ≥75 kg). Subjects were either not on antiretroviral therapy with a CD4+ cell count >500 cells/mm3 or had virologically suppressed HIV-1 with a CD4+ cell count >200 cells/mm3. 95% of patients received antiretroviral therapy at the time of enrolment. Preliminary SVR12 data are available for 210 subjects.
b. Other includes subjects who did not achieve SVR12 and did not meet virologic failure criteria (e.g., lost to follow-up). Table 16 presents the subgroup analysis by genotype for cirrhosis. Table 16: SVR12 rates for selected subgroups by genotype in study PHOTON-1
Patients awaiting liver transplantation - Study 2025 Sofosbuvir was studied in HCV infected subjects prior to undergoing liver transplantation in an open-label clinical study evaluating the safety and efficacy of sofosbuvir and ribavirin administered pre-transplant to prevent post-transplant HCV reinfection. The primary endpoint of the study was post-transplant virologic response (pTVR, HCV RNA <LLOQ at 12 weeks post-transplant). HCV infected subjects, regardless of genotype, with hepatocellular carcinoma (HCC) meeting the MILAN criteria received 400 mg sofosbuvir and 1,000-1,200 mg ribavirin daily for a maximum of 24 weeks, subsequently amended to 48 weeks, or until the time of liver transplantation, whichever occurred first. An interim analysis was conducted on 61 subjects who received sofosbuvir and ribavirin; the majority of subjects had HCV genotype 1, 44 subjects were CPT class A and 17 subjects were CPT class B. Of these 61 subjects, 44 subjects underwent liver transplantation following up to 48 weeks of treatment with sofosbuvir and ribavirin; 41 had HCV RNA <LLOQ at the time of transplantation. The virologic response rates of the 41 subjects transplanted with HCV RNA <LLOQ is described in Table 17. Duration of viral suppression prior to transplantation was the most predictive factor for pTVR in those who were HCV RNA <LLOQ at the time of transplantation. Table 17: Virologic response post-transplant in subjects with HCV RNA <LLOQ at the time of liver transplantation
b. pTVR: post-transplant virologic response (HCV RNA <LLOQ at 12 weeks post-procedure). In patients that discontinued therapy at 24 weeks, according to protocol, the relapse rate was 11/15. Overview of outcomes by therapeutic regimen and treatment duration, a comparison across studies The following tables (Table 18 to Table 21) present data from Phase 2 and Phase 3 studies relevant to the dosing to help clinicians determine the best regimen for individual patients. Table 18: Outcomes by therapeutic regimen and treatment duration, a comparison across studies in genotype 1 HCV infection
a. For previously treated patients with genotype 1 HCV infection, no data exists with the combination of sofosbuvir, peginterferon alfa and ribavirin. Consideration should be given to treating these patients, and potentially extending the duration of therapy with sofosbuvir, peginterferon alfa and ribavirin beyond 12 weeks and up to 24 weeks; especially for those subgroups who have one or more factors historically associated with lower response rates to interferon-based therapies (prior null response to peginterferon alfa and ribavirin therapy, advanced fibrosis/cirrhosis, high baseline viral concentrations, black race, IL28B non CC genotype). b. These are exploratory or Phase 2 studies. The outcomes should be interpreted with caution, as subject numbers are small and SVR rates may be impacted by the selection of patients. c. Summary data from both studies. Table 19: Outcomes by therapeutic regimen and treatment duration, a comparison across studies in genotype 2 HCV infection
a. These data are preliminary. b. These are exploratory or Phase 2 studies. The outcomes should be interpreted with caution, as subject numbers are small and SVR rates may be impacted by the selection of patients. In the ELECTRON study (N = 11), the duration of peginterferon alfa ranged from 4-12 weeks in combination with sofosbuvir + ribavirin. c. All patients were non-cirrhotic in these two studies. Table 20: Outcomes by therapeutic regimen and treatment duration, a comparison across studies in genotype 3 HCV infection
a. These data are preliminary. b. These are exploratory or Phase 2 studies. The outcomes should be interpreted with caution, as subject numbers are small and SVR rates may be impacted by the selection of patients. In the ELECTRON study (N = 11), the duration of peginterferon alfa ranged from 4-12 weeks in combination with sofosbuvir + ribavirin. c. All patients were non-cirrhotic in these two studies. Table 21: Outcomes by therapeutic regimen and treatment duration, a comparison across studies in genotype 4, 5 and 6 HCV infection
n = number of subjects with SVR12 response; N = total number of subjects per group. In repeat dose toxicology studies in rat and dog, high doses of the 1:1 diastereomeric mixture caused adverse liver (dog) and heart (rat) effects and gastrointestinal reactions (dog). Exposure to sofosbuvir in rodent studies could not be detected likely due to high esterase activity; however, exposure to the major metabolite GS-331007 at the adverse dose was 29 times (rat) and 123 times (dog) higher than the clinical exposure at 400 mg sofosbuvir. No liver or heart findings were observed in chronic toxicity studies at exposures 9 times (rat) and 27 times (dog) higher than the clinical exposure.
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