Effect of pegylated interferon 9 Effect of pegylated interferon on non-responders and relapsers with interferon *Hisham O. Akbar, Mahmoud S. Al Ahwal ABSTRAC T. Objectives: To assess whether a combination of pegylated interferon (interferon conjugated with polyethylene glycol) and ribavirin can improve the response rate in patients with chronic hepatitis C who either did not respond to (Non-responders), or had relapsed after responding to (Relapsers) standard interferon and ribavirin combination therapy. Patients and methods: In this prospec- tive study, 20 chronic hepatitis C patients (comprising 16 Non-responders and 4 Relapsers to previous treatment with alpha interferon and ribavirin), were treated with pegylated interferon-2b weekly and ribavirin daily for one year. Eleven patients had genotype 4, eight were of genotype 1 and one patient had genotype 3. Response to treatment was determined based on normalisation of liver enzymes and negative viral load (assessed using qualitative HCV RNA PCR) at end of treatment (ETR) and 6 months off treatment (SVR). Results: Seven patients (35%) achieved normalisation of liver enzymes and negative viral load at the end of treatment. However, only 2 patients (10%) managed to retain these levels after six months off treatment. The latter two patients had been previous Relapsers. Conclusion: Combination of pegylated interferon and ribavirin may be beneficial in previous relapsers with standard interferon-ribavirin combination therapy, but is unlikely to achieve sustained virological response in non-responders. Key words: pegylated interferon, ribavirin, hepatitis C virus, non-responders, relapsers Department of Medicine, King Abdulaziz University Hospital, Jeddah P.O.Box 80215, Jeddah 21589, Saudi Arabia. *To whom correspondence should be addressed. Email: gastro20000@yahoo.com feron. Several studies have shown pegylated interferon’s superiority in improving response rate in naïve patients, alone or in combination with ribavirin.6–9 This additional effect is yet to be proven on previous non-responders or those who relapsed after combination therapy with riba- virin and interferon. P A T I E N T S A N D M E T H O D S : Patients who had been treated earlier with combination therapy (interferon and ribavirin) for one year and did not respond or had relapsed off treatment, were con- sidered for this study. Non-responders were defined as those patients who, during treatment, had increased liver enzymes (AST/ALT) and persistent detectable viral load, measured using qualitative HCV RNA PCR (Roche T RE ATMENT OF HEPATITIS C VIRUS (HC V) infections has been a subject of different studies. Alpha-interferon was the first drug approved for treatment of HCV. Initially interferon monotherapy for 6 months was a common practice but it was associated with high relapse rates.1 Extended treatment with inter- feron for one year was found to decrease the relapse rate and increase sustained response.2,3 Subsequently ribavi- rin was approved for treating HCV in combination with interferon. One year-long interferon-ribavirin combi- nation therapy resulted in higher response.4,5 Despite such improvement, there are many patients who do not respond to treatment or relapse off treatment. Recently, pegylated interferon has been approved for treatment of patients with chronic HCV. Attachment of polyethylene glycol molecule to interferon (pegylation) has the advan- tage of prolonged action as compared to regular inter- SQU JOURNAL FOR SCIENTIFIC RESEARCH: MEDICAL SCIENCES 2002, VOL. 4, NO. –2, 9–3 ©SULTAN QABOOS UNIVERSIT Y Interferon �� ��� ������ ���������� ����� ����� ������������ � ��� ������ ������� �� �������� ���������� �������� ����� ����� ����� ���� �������� :�����:�������� ������ � ��� ������ ������� ������ ������ ���� ��� ������ ���������� ������ �� ������ �������� ���������� .������� :��� ������ �� �������� ���� ����������� �� ������ ���������� ����� ���������� ���� ����� ������ �����.�������:��������� ���� ����� ����� ������ �� ���� ��� ��� ��� ������ ������� ������� ����� ����� �� ���� � ����� �� ���� ����� ����������� ����� ����� �� ���������������� ��� �������.������:����� ���� ���� ������ ���������� ��� �� �������� ���������� ��� �� ��������� ����� �� ����� ������. 0 Diagnostics). Relapsers were those patients who had normal liver enzymes and undetectable viral load (HCV RNA PCR-qualitative) at end of treatment that was not persistent 6 months after stopping combination therapy. All patients were at least 6 months and not more than 2 years off-treatment. End of Treatment Response (ETR) was defined as nor- malisation of liver enzymes and negative HCV RNA PCR (qualitative) at end of treatment. Sustained Virologic Response (SVR) was defined as persistent normalisation of liver enzymes and negative HCV RNA PCR (quali- tative) 6 months off treatment. SPSS statistical package was used for analysis. Descriptive statistics were done. P- value was set at <0.05 for statistical significance. Patient characteristics Twenty patients, comprising 6 Non-responders and 4 Relapsers (to a previous combination treatment) were included in the study. The patients were followed for the period from March 2000 to November 200 at King Abdulaziz University Hospital, Jeddah, Saudi Arabia. Before treatment, complete blood count (CBC), liver function test (LFT), prothrombin time (PT), thyroid function test (TFT/T4, TSH), quantitative HCV RNA PCR (Roche Diagnostics), gastroscopy and abdominal ultrasound were conducted. Quantitative HCV RNA PCR results were grouped into low (<06 copies/ml), moderate (06–07 copies/ml) and high (>07 copies/ ml). Previous liver biopsy results before treatment with combination therapy were considered while assessing patient response to pegylated interferon. Histological severity using grading for necroinflammatory activity and staging for degree of fibrosis was reported as mild hepatitis (grade 2, stage ), moderate hepatitis (grade>2, stage 2), severe hepatitis (grade>2, stage 3) and liver cirrhosis (stage 4). Patients included in the study were started on pegylated interferon-2b (Schering Plough USA) 00 mcg subcutaneously weekly, together with ribavirin (400 mg) twice daily for one year. CBC and LFT were repeated weekly for the first month and then monthly until the end of treatment. TFT and qualita- tive HCV RNA PCR were repeated after 6 months, end of treatment (2 months) and 6 months off treatment together with LFT. The patients had given their writ- ten consent. Female patients were instructed to practise contraception during childbearing period. Fourteen patients (70%) were male and 6 (30%) were female. Their mean age was 4 years (29–6 years), and average weight, 74.4 kg (53–94 kg). None of the patients had esophageal varices, and their abdominal ultra- sound did not show evidence of ascites, splenomegaly or focal liver lesions. Viral load was low in three patients (5%), moderate in 6 patients (80%), and high in one patient (5%). Eleven patients (55%) were of genotype 4, five patients (25%) had genotype a, three patients (5%) had genotype b, and one patient (5%) had genotype 3 (consistent with the most prevalent genotypes among this community where genotypes  and 4 account for > 86.4%). Two patients (0%) had mild hepatitis, 8 patients (40%) had moderate hepatitis, 6 patients (30%) had severe hepatitis and 4 patients (20%) had liver cirrhosis. R E S U L T S Seven patients (35%) achieved ETR with pegylated inter- feron and ribavirin, and 3 of them had low viral load and 4 had moderate viral load; 2 patients had mild hep- atitis and 4 had moderate hepatitis. Four patients had already achieved ETR with previous treatment with reg- ular interferon combination therapy, but were Relapsers, and 3 patients were Non-responders. Two patients (0%) had SVR (genotype a,3) while another patient, of genotype 4, had persistent normal AST level with posi- tive HCV RNA PCR 6 months off treatment (Sustained Biochemical Response – SBR). All patients who had SVR or SBR were Relapsers [Table ]. Patients who achieved ETR with the current treatment had already negative HCV RNA PCR (qualitative) after 6 months during treat- ment (p<0.05). Two patients (one with low and another with moderate viral load) had achieved SVR (p>0.05). These two patients had respectively mild and moderate hepatitis (p>0.05). Seventeen patients (85%) had leucopoenia (4 patients had WBC 3.4×09/l, 3 patients had WBC 2.3×09/l) and 3 patients (5%) had thrombocytopoenia (<50×09/l) during current treatment. On reviewing these patients’ previous CBC results while they were on regular inter- feron combination therapy, it was found that 6 of them (30%) had leucopoenia (5 patients had WBC 3.4×09/l, Table 1. Comparison of responses to treatment with pegyalated and non-pegylated interferons Drug used Number of patients who responded ETR SVR SBR Interferon and ribavirin 4 (20%) 0 0 Pegylated interferon and ribavirin 7 (35%) 2 (10%) 1 (5%) ETR: End of treatment response SVR: Sustained virologic response SBR: Sustained biochemical response A K B A R & A L A H WA L  and one had 2.3×09/l) and none had thrombocytopoe- nia (P>0.05). One patient was hypothyroid on replacement therapy from previous interferon treatment; however l-thyroxin requirement of this patient did not increase during the current treatment with pegylated interferon and ribavi- rin. None of the other patients developed denovo thy- roid dysfunction. None of the patients experienced significant subjective constitutional symptoms with the current therapy as compared to previous therapy of reg- ular interferon-ribavirin combination. D I S C U S S I O N Since the discovery of HCV, treatment of patients chronically infected with this virus was continuously modified to achieve higher response rates. Several vari- ables were found to affect treatment response, includ- ing age at infection, gender, viral load, virus genotype, stage of liver fibrosis and patient’s immunity status.4,5,10– 13 Iron overload was found to decrease patient response to treatment; however iron reduction via phlebotomy did improve the response.14,15 Response to treatment in HCV patients is assessed by the normalisation of liver enzymes and decrease in viral load beyond detec- tion level (qualitative HCV RNA PCR <00 copies/ml). Hence non-responders and relapsers represent the same group of patients where both groups have persist- ent viraemia at end of treatment with the difference in the load being above or below detection level depend- ing on the test used. With the improvement of viral load assays with lower limit detection level, more cases of true non-responders rather than relapsers should be diagnosed in future. Non-responders or relapsers to old treatment regimen have been candidates in dif- ferent controlled studies for new regimens to improve their response as compared to naïve patients. Extended and higher dose treatment with interferon monotherapy was associated with decreased relapse rate and sus- tained response rate in 20–40% of cases.16 Introduction of combination therapy was more effective than inter- feron monotherapy in naïve patients. However, results were disappointing with re-treatment in patients who did not respond to initial interferon monotherapy (3– 29%) and was associated with sustained response in 46–58% in selected group of relapsers.17–19 Viral muta- tion and development of quasispecies in response to standard interferon regimen together with pre-treat- ment patients and viral demographics may explain the response failure in the majority of patients infected with HCV to interferon monotherapy or combination ther- apy (>50%).20 Long-acting pegylated interferon, which is associated with constant levels between consecutive doses, was found to be more effective than regular inter- feron in naïve patients.6–9 In our study, more patients had ETR with pegylated interferon combination therapy as compared to previous regular interferon combination therapy (7 versus 4 patients). This effect was influenced by the viral load (p<0.05) rather than by the degree of fibrosis (p=0.056). Unfortunately this response was not durable after stopping treatment where only 2 patients (0%) had SVR and 5 patients relapsed off treatment (7.4%). SVR was only achieved in a subset of patients that had viral load below detectable level with previous standard combination therapy (Relapsers). This addi- tional effect of pegylated interferon is probably through decreasing viral mutation or development of less quasis- pecies strains. Though pegylated interferon was slightly superior to regular interferon in this group of patients, this effect is modest since it does not change most of pre treatment host and viral factors that also influence patient response. In a similar study by Afdahl et al using pegylated interferon alfa-2a plus ribavirin only preliminary ETR was reported. ETR was 6% in relapsers and 25% in non-responders.21 Different other combinations were used with pegylated interferon including mycopheno- late mofetil and amantadine. The highest ETR reported was 7% in relapsers and 40% in non-responders upon adding amantadine to pegylated interferon and ribavi- rin.21 In our study ETR was 00% in Relapsers and 8.7% in Non-responders, however SVR was 50% in Relapsers and 0% in Non-responders. Other dugs have been used as adjuvant or alter- native therapy including ursodeoxycholic acid,22 non- steroidal anti inflammatory drugs,23 thymosin,24 ISIS 4803 (anti-sense therapy),25 histamine dihydrochlo- ride (Maxamine)26 and interlukins 0 and 2,27,28 none of them improved viral response rates. New investiga- tional agents such as proteinase inhibitors, Albuferon, VX-497 and ribozyme therapy may prove to be benefi- cial in future.29–31 Currently there is no solid consensus regarding treat- ment of non-responders or relapsers after standard interferon-ribavirin combination therapy. However it seems that relapsers may benefit from pegylated inter- feron combination therapy. Further studies are required to assess whether prolonged or maintenance pegylated interferon alone or in combination with other anti viral agents can improve response in this group of patients. E F F E C T O F P E G Y L AT E D I N T E R F E R O N 2 C O N C L U S I O N This study suggests that therapy with pegylated inter- feron in combination with ribavirin may be beneficial in patients with HCV who relapsed after initially clear- ing HCV RNA during previous treatment with stand- ard interferon-ribavirin combination therapy. Patients with persistent viral load during previous standard com- bination therapy are unlikely to respond to pegylated interferon-ribavirin combination therapy and should be enrolled in more clinical trials with different drugs and regimen to achieve a better response. R E F E R E N C E S . Davis GL, Balart LA, Schiff ER, Lindsay K, Bodenheimer HcJr, Perrillo RP, et al. Treatment of chronic hepatitis C with recom- binant interferon alfa. 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