Prolonged treatment (2 years) with different doses (3 versus 6 MU) of interferon α-2b for chronic hepatitis type C

Prolonged treatment (2 years) with different doses (3 versus 6 MU) of interferon a-2b for chronic hepatitis type C Results of a multicenter randomized trial Giorgio Saracco, Elisabetta Borghesio, Pietro Mesina ‘, Antonello Solinas’, Claudia Spezia’. Franc0 Macor3, Vittorio Gallo4, Livio Chiandussi4, Carlo Donada5, Valter Donadon’, Fulvio Spirito6, Alessandra Mangia6, Angelo Andriulh ‘6, Giorgio Verme and Mario Rizzetto ltzfettiw. O.cp&le S. Frmwescr~, ~Vuoro, -‘Z.stifuto c/i Patologiu Dipurtimerlto tli Gastrorntcvok,gia, O.~peclde Molinettr, Turing, ’ Dirisione Mtrluttie 1. Ospedul~ S. I i’to, Utliwrsizj~ e Clinica Me&u, Unrwrsitu di Sursuri. ‘Divisione B, Ospedule Am&o c/i Suvoict, Twin, 4Ptr/olujiirr Mdictr of’ Twin. iDivisiorw r/i ,Mrdicim/ III, O.~p~~lcrle di Porder~onr. urrtl ‘Dirisionr di Gcr.st,ocrlrr~roiogrtr. C'usrr Solliew ddkr Sof%~cw~c~,Sun Gimtrnrli Rotomio,

Ittill.

Background/Aims: To examine the effect of prolonged treatment with different doses of interferon a-2b on the relapse rate in patients with chronic hepatitis C. Met/~& One hundred and seventy-one patients with non-cirrhotic chronic hepatitis C were enrolled in an Italian multicenter trial. All patients were treated for 3 months with 3 000 000 Units (3 MU) of interferon a-2b given subcutaneously three times a week (t.i.w.). Patients with abnormal alanine aminotransferase (ALT) values were given 6 MU of interferon for an additional 3 months. If ALT remained persistently abnormal, therapy was then suspended. If ALT levels were normal, therapy was continued (6 MU t.i.w.) for an additional 18 months (total=2 years). Patients with normal ALT were randomly assigned to two groups, one receiving 3 MU and the other receiving 6 MU t.i.w. for an additional 21 months (total=2 years). Follow-up continued for 2 years after therapy withdrawal. Results: Seven patients stopped treatment during the first 3 months. Of the remaining 164 patients, 76 (46%) showed abnormal ALT levels after 3 months of therapy: 11 of these (14%) normalized ALT values when given 6 MU and a sustained response was maintained in eight during the follow-up. Overall, 54 and 34 patients were allocated respectively to the groups

receiving the 3 MU and 6 MU long-term treatment. At the end of therapy, 35154 patients of the group 3 MU and 21/34 patients of the group 6 MU showed normal ALT levels (65% vs 62%, p=N.S.). After 2 years of follow-up, 24/35 (69%) patients of the group 3 MU and 16/21 (76%) of the group 6 MU were still in remission (p=N.S.). In an intention-to-treat analysis, 48/171 (28%) patients showed a long-term response (normal ALT values, HCV-RNA negative). About 65% of the sustained responders showed low baseline viremia compared with 33% of nonresponders (p=O.OOS) while genotype lb was more frequently found among non-responders than in long-term responders (84% vs 25%, p=O.OOOl). Conclusions: About 14% of patients who do not respond to a 3-month course of 3 MU of interferon normalize ALT levels when given 6 MU. In prolonged treatment, there is no significant difference between 3 and 6 MU in inducing a sustained response. Patients with low baseline viremia and genotype 2a respond significantly better to prolonged interferon therapy than highly viremic patients with genotype lh

W

thrice weekly for 6 months), a permanent therapeutic response is obtained in no more than 20% of treated

ITH THE

hepatitis

standard treatment regimen of chronic C (3 000000 IU of interferon given

Received 8 Ocfoher. IY96; rrvi.red N Junuur~~: ucepted

Correspondence:

Giorgio Saracco,

31 J~muor~~1997

MD. Department of Gastroenterology. Molinette Hospital, Corso Rramante 88, 10126 Turin, Italy. Tel: 39-11-6335558. Fax: 39- 1l-66342 13.

56

Key words: Chronic RNA; Interferon.

hepatitis

C; Genotype;

HCV-

patients (l--7). This figure may even be optimistic, as relapses as late as 3 years after therapy withdrawal have been observed (8). More favorable long-term results have been recently reported with prolonged therapy courses (9-l 3). In this study we evaluated whether the dosage of IFN (3 vs 6 MU) is a significant variable

IFN in chronic hepatitis C

in prolonged (2-year) therapy courses. The objective of the study was to establish whether the increased dose could further reduce the relapse rate after therapy suspension. A protracted clinical and virologic follow-up was performed in order to detect possible late relapses. Pretherapy features were also evaluated by univariate analysis to determine whether associations exist between baseline variables and a sustained response.

Patients and Methods From June 1990 to September 1991, 171 patients with non-cirrhotic chronic hepatitis C were enrolled in an Italian multicenter randomized trial. The inclusion criteria were as follows: 1) Abnormal serum alanine aminotransferase (ALT) values for at least 6 months before entry. 2) Presence of antibodies against the hepatitis C virus (anti-HCV) detected by ELISA-1 assay (Chiron Corporation, Emeryville, CA, USA). 3) Absence of histologic cirrhosis. 4) Absence of the hepatitis B surface antigen (HBsAg) and signs of other causes of chronic liver diseases. 5) Absence of current or past drug addiction. 6) Absence of antibodies against the Human Immunodeficiency Virus (anti-HIV). All patients gave written informed consent for inclusion. In each patient, recombinant interferon a-2b (IFN) was given subcutaneously at a dose of 3 MU thrice weekly for an initial period of 3 months. In patients whose ALT levels remained abnormal at the end of this period, the dose of IFN was increased to 6 MU three times a week for a further 3 months. Patients from this group who did not attain ALT normality within this time were considered treatment failures. and were with-

drawn from therapy and lost to follow-up. Patients who attained normal ALT values were kept on the 6 MU dosage thrice weekly for another 18 months. Patients who showed normal ALT levels at the end of the first 3 months of treatment at 3 MU were randomized using a computer-generated list into two groups, one (Group 1) receiving 3 MU three times a week for 21 months, the other (Group 2) receiving 6 MU thrice weekly for 21 months. The patients with normal ALT values at the end of therapy were followed-up for at least 2 years; they were seen every month during therapy and bimonthly during the follow-up. At each visit, blood was drawn for routine hematologic and biochemical tests and aliquots of serum were stored at -80°C immediately after collection. The response to IFN was defined as complete when the ALT levels were normal at the end of therapy. The response was considered sustained if the ALT values were normal during the 2-year follow-up. A relapse was defined as a return to abnormal ALT levels after a complete response within the 2-year post-therapy period; the relapse was confirmed by three abnormal tests performed every 2 weeks. All the patients underwent a liver biopsy within the 6 months prior to inclusion into the study; a second liver biopsy was proposed to each patient who concluded the 2-year treatment course at the end of the follow-up. Each liver biopsy was reviewed blind according to the Knodell’s scoring system (14) by two pathologists. Baseline sera were available in 95 patients; they were retrospectively tested for viremia and genotype. Endtherapy and follow-up sera were tested for viremia by Polymerase Chain Reaction (P.C.R.) only in patients who concluded the 2-year course of treatment. Virology

1 171

/ Abnormal

Abnormal

STOP

HCV+

1

PATIENTS

ALT

ALT

Normal

Same regimen

for 18 months

additional

36

RESPONSE

6 pts.

(76%)

24

pts.

Fig. 1. Study design and biochemical tients).

pts.

(62%)

+ (2

YEARS)

]

+

+

+

ALT 21

c55%)

‘+

+ [SUSTAINED

MS.

(60%)

16 pts.

(72%)

response (pts., pa-

Quantitation of HCV-RNA was performed by branched DNA (bDNA 1.0) according to the manufacturer’s instructions (Chiron Corporation, Emeryville, CA, USA). This assay, based on signal amplification, has a sensitivity of 3.5~10~ HCV genomes equivalents/ml (genEq/ml). Serum samples below this cut-off were evaluated for HCV-RNA by a sensitive nested P.C.R. HCV-RNA was extracted from 50 yl serum, reversed transcribed and amplified as previously described (15). The sensitivity of this assay was 50-200 genEq/ml of serum. Genotypes 1a and 1b were identified using DNA enzyme immunoassay (DEIA, Sorin Biomedica, Saluggia, Italy). In the assay, reversed transcribed and amplified RNA from the core region of HCV is hybridized with a single stranded probe coated on the wall of

57

G. Saracco TABLE

et al

1

Baseline characteristics treated with interferon Characteristics

n

Mean age (years) Sex (M/F) ALT (mean?SD) Liver histology* C.P.H. C.L.H. C.S.H. C.A.H. Knodell index (mean?SD) Source of infection Sporadic Blood transfusion Viremia** (genEq/ml) >3sx lo5 <3.5x 10’ Genotype lb**

of a-2b

164 patients

with

1

hepatitis

Total patients

(3 MU)

Group 2 (6 MU)

164 47.5 93/l 1 159236

54 45.4 33121 157246

34 48.5 2202 159239

53 10 6 95

(32.4%) (6%) (3.7%) (57.9%)

8.2i2.8 117 (71.3%) 47 (28.7%) 55.8% 44.2% 64.3%

Group

chronic

23 4 2 25

(42.6”%) (7.4%) (3.7%) (46.3%)

l.lIk2.7

13 2 3 16

C

(38.2%) (5.8%) (8.8%) (47.2%)

6.922.6

31 (57.4%) 23 (42.6%)

21 (61.7%) 13 (38.3%)

40.6% 59.4”/;i 56.2%

45.8% 54.2% 45.8%

* C.PH.=Chronic Persistent Hepatitis. C.L.H.=Chronic Lobular Hepatitis. C.S.H.=Chronic Septal Hepatitis. C.A.H.=Chronic Active Hepatitis. ** Quantification by branched DNA and genotype identification were performed retrospectively in 95 patients.

the microtiter plate wells through a streptavidin-biotin bond. The addition of a monoclonal antibody that reacts only with the double stranded DNA and an enzyme tracer provides a detection system similar to that employed in an enzyme immunoassay. Samples unreactive in this assay (negative for genotype la and lb) were further evaluated by a solid phase probe specific hybridization. The biotinylated amplification products from the 5’ uncoding region were hybridized with line probes (LIPA) affording the detection of the five most common genotypes; with this system two subtypes can be determined for each type. Statistical analysis Dichotomous variables were compared using the chisquared test; quantitative variables were compared with the Student’s t-test. To determine the strength of association between pretreatment selected variables and sustained response, a logistic regression model was used.

Results No significant difference was found between the groups regarding age, sex, mean baseline ALT values, liver histology, source of infection, viremia and genotypes (Table 1). Of the 171 patients included in this study, seven stopped treatment during the first 3 months (six be58

cause of side effects and one because of incorrect inclusion). Of the remaining 164 patients, 76 (46.3%) showing abnormal ALT levels were given 6 MU of IFN t.i.w. for an additional 3 months. At the end of this period, 11 of these (14.4%) normalized ALT values and continued therapy for a further 18 months. One showed an ALT breakthrough during therapy and abandoned the study, but the dose was not reduced in the remaining 10 patients, during the treatment. Of the 10 patients who completed the 2-year therapy. two (20%) relapsed within 2 months from the treatment suspension. Eighty-eight patients (53.7%) exhibited normal ALT levels at 3 months: 54 were randomized to Group 1 (3 MU) and 34 to Group 2 (6 MU). In Group 1, the treatment was suspended prematurely in 19 patients (35%): five because of adverse events, two for failing to comply with the protocol and 12 (22.2”/0) because of an ALT breakthrough. In Group 2 therapy was stopped prematurely in 13 patients (38.2%): six because of side effects, two for lack of compliance and five (14.7%) because of an ALT breakthrough. Of the 35 Group 1 patients who showed normal ALT values at the end of treatment, I 1 (31.4%) relapsed during the follow-up l--7 months after therapy withdrawal. Of the 21 Group 2 patients with normal ALT levels at the suspension of therapy, five (23.8%) relapsed in the follow-up, l-2 months after treatment cessation. The difference was not significant @=N.S.). Due to side effects, 50% reduction of the dosage was necessary in one of the 35 Group 1 patients (2.8%) and four of 21 Group 2 patients (19%) @=N.S.) who had shown normal ALT levels at the end of therapy. Overall, the sustained response rate in Group 1 (24154, 44.4%) was not different from that observed among Group 2 patients (16134, 47%) (p=N.S.). Evaluating the results with an intention-to-treat analysis and considering even the patients in the dose escalation arm, 48 (28%) of the 171 patients recruited in the study maintained a sustained response. Baseline viral load and HCV genotypes were retrospectively established in 95 patients for whom pre-therapy sera were available. At the start of treatment 90 of the 95 patients (94.7%) had HCV-RNA detectable in serum; 53 (55.8%) were highly viremic, 37 (38.9%) showed low levels of HCV-RNA below the cut-off of the bDNA test, detectable only by P.C.R. Forty-seven of the patients for whom baseline virologic data were available concluded the 2-year course of therapy: 32 were sustained responders and 15 relapsers. Among sustained responders, only four (12.5%) were still viremit at the end of treatment; one continued to be HCV-RNA positive (by P1C.R.) throughout the follow-

IFN in chronic hepatitis C

up despite having normal ALT levels while the remaining three were HCV-RNA-negative 2 years after the therapy suspension. Of the 15 relapsers, three (20%) had detectable HCV-RNA at therapy suspension but all of them were viremic 2 years after. Genotype lb was the predominant genotype (64.3% versus 29.5% genotype 2a) and was homogeneously distributed between the two groups (Table 1). Virologic data stratified according to the biochemical outcome are reported in Table 2. Among sustained responders, only 34% of the patients were highly viremic at baseline without a significant difference between Group 1 and 2. In contrast, about 60% of non-responders/relapsers showed high levels of viremia before treatment (p= 0.005). Genotype lb was found in 84% of non-responders/relapsers and in 25% of sustained responders while genotype 2a was detected respectively in 11% and 65% of these patients (p=O.OOOl). Histology The mean baseline Knodell’s acivity index was similar in the two groups at the start of therapy (Table 1). Of the 66 patients treated for 2 years, 29 agreed to undergo a second liver biopsy 2 years after the therapy suspension; 21 were sustained responders and eight relapsers. A dramatic improvement was observed among

TABLE

Predictive factors of sustained response Sustained responders (irrespective of their group of treatment) and non-responders/relapsers were stratified according to sex, age, mean baseline ALT levels, source of infection, viremia, genotype and histology. The results of the univariate logistic regression analysis correlating these baseline characteristics with the longterm outcome of IFN therapy are reported in Table 4. Sex, age, pretreatment levels of ALT and type of exposure were not predictive of long-term response. A significant association between low levels of viremia, genotype 2a, mild histologic forms and sustained response was found. Side effects Of the 171 patients originally included in this study, 17 (10%) stopped the treatment for side effects, six abandoning the study during the first 12 weeks: two of these

2

Baseline virologic

characteristics

Median HCV-RNA* (genEq/ml X 106)

of 95 patients

stratified

to their clinical outcome

Non-responders/relapsers

Sustained

(95)

(63)

(15)

61 28 3 3

* Corrected arithmetically Non-responders/relapsers

according

Total no. of patients

3.8

HCV genotype lb 2a 3a 4a

TABLE

sustained responders with no significant differences between the two groups, while no substantial change was found in the eight relapsers. When stratified according to their therapeutic response, patients with baseline minor histologic forms appeared to maintain a more sustained response than patients with aggressive pictures (p=O.Ol, Table 3).

4.7**

(64%) (30%) (3%) (3%)

for differences in genotype versus sustained responders:

response,

3 MU

response,

6 MU

1.4**

1.2**

53 (84%)*** l(ll%) 2 (3%) 1 (2%)

Sustained (17)

4 (27%)*** 9 (60%) 1 (6.5%)

4 (24%)*** 12 (70%) -

1 (6.5%)

according to Collins et al. (Ann Biochem ** p=O.O05; *** p=O.OOOl.

1 (6%) 1995; 226: 120-9).

3

Baseline histologic

characteristics

of the 164 patients

stratified

according

to their clinical outcome Sustained

(164)

(116)

(24)

(24)

C.F!H. C.L.H.

53 (32.4%) 10 (6%)

30 (25.9%) 8 (6.9%)

12 (50%) 2 (8.4%)

11 (45.9%) -

C.S.H. C.A.H.

6 (3.7%) 95 (57.9%)

78 (67.2%)

C.RH=Chronic * Eight patients

8.222.8

Persistent Hepatitis. C.L.H. =Chronic in the dose escalation arm included.

9.2k3.1

Lobular

Hepatitis,

C.S.H.=Chronic

3 MU

response,

Non-responders/relapsers

Knodell’s index (mean? SD)

response,

Sustained*

Total no. of patients

1 (4.1%) 9 (37.50/o)

5 (20.8%) 8 (33.3%)

6.822.6

6.622.8

Septal Hepatitis.

C.A.H.=Chronic

6 MU

Active Hepatitis.

59

TABLE

4

Results of univariate tures with long-term

Sex (males/females) Mean age (years) Mean ALT (IU) Source of infection (blood transfusion/ sporadic) Viremia (genEqim1) >3.5x IO’ <3.5x10” HCV genotype lb Histology Knodell’s index (meani_SD)

logistic regression analysis correlating initial feaoutcome of treatment with IFN a-2b Non responders/ relapsers (116)

17

67i49 48.9 161.2

N.S. N.S. N.S.

32184

N.S.

IS/33

66.7% 33.3%

0.005

34.3(‘4, 65.7’!6

84.1%

0.0001

25%

9.223.1

Sustained responders (48)

0.01

26:22 46.5 156.8

6.722.7

because of neutropenia, three because of headache and myalgias and one who developed an ALT peak at the 3rd month with development of anti-Liver Kidney Microsome (LKM) antibodies. Of the remaining 11 patients (five from Group 1 and six from Group 2), four developed autoimmune thyroiditis (two with irreversible functional loss of the gland), six were dropped because of neutropenia, and in one therapy was suspended because of severe itching. Such adverse events were homogeneously distributed between the two groups. Generally, Group 2 patients reported a reduced quality of life more often than Group 1 patients; however, none of them stopped the usual working activities.

Discussion In the early 1990’s the recommended treatment regimen for patients with chronic hepatitis C was 3 MU of IFN three times a week for 6 months. The disappointing long-term results obtained with this schedule have prompted clinicians to look for a more aggressive approach, such as increasing the dosage or prolonging the period of administration. The use of high dosages of IFN has produced controversial results (16-20). In contrast, recent studies (9913) have consistently stressed the importance of the period of administration. In particular, a recent metanalysis (21) evaluating the benefits of higher doses or longer duration in comparison with a standard IFN regimen found that the best efficacy/risk ratio was in favor of 3 MU t.i.w. for at least 12 months. Discrepancies have emerged regarding the efficacy of prolonged therapeutic courses in patients with unfavorable viral genotypes, Chemello et al. 60

(17) showed that a 12-month therapy induces a higher long-term response rate compared with a 6-month course in patients with genotype 1b; these results were not confirmed by a recent Italian study (22). However. both studies adopted therapeutic protocols with tapering doses: such approach is not yet considered the optimal one as there are conflicting results regarding the efficacy of a gradual reduction in the IFN dose (23.24). Our study confirms that a prolonged administration of IFN is feasible and induces an overall long-term response in about 28(X, of treated patients; it indicates, however, that the IFN dosage does not significantly influence this result. Although the patients treated with 6 MU appeared to be less prone to relapse than those treated with 3 MU (23.8% vs 31.4%). the difference between the groups was not significant. A protracted 2-year follow-up has provided no evidence that prolonging treatment may have simply delayed relapse as all the enzymatic recurrencies occurred within 7 months from therapy withdrawal; clearance of viremia was obtained in almost all the sustained responders at the end of therapy and only one of them is still HCVRNA-positive 2 years after the suspension of IFN, suggesting that in most patients viral infection has been eliminated. The histologic data from the follow-up liver biopsies, although partial. show a consistent amelioration of the hepatic disease. The exclusion of patients with cirrhosis from this trial was motivated by the fear of dangerous side effects related to the prolonged treatment. Recently, however. the use of IFN in patients with cirrhosis has not substantiated this concern (10). In our study the rate of patients who prematurely suspended therapy after randomization was quite high (35% in Group 1 and 3%:) in Group 2) but the number of the patients dropping out from the trial because of side effects (10%) was lower than in studies (3.10) that used smaller dosages for shorter times. suggesting that cirrhosis may be a factor of diminished tolerance to IFN. The absence of patients with cirrhosis can also explain the slightly higher rate of sustained responders obtained in our trial compared with a similar study conducted by Poynard et al. (IO) who treated 103 HCV+ patients with 3 MU of IFN (x-2b thrice weekly for 18 months. The high rate of premature therapy withdrawal was mainly due to an enzymatic flare after an initial normalization, the “ALT breakthrough”. The ALT “breakthrough” is a complex phenomenon which might be influenced by multiple factors such as the development of anti-IFN antibodies, emergence of HCV escape mutants and downregulation of specific IFN cell receptors (25-28). All these can be triggered by a prolonged IFN course. In our patients, however,

IFN in chronic hepatitis C

the role of breakthrough was not different from that observed in a study that used 2 MU of IFN three times a week for 6 months (2). In keeping with previous reports (29-34), in our study the patients more likely to maintain the therapeutic response were those with low baseline viremia and genotype 2a; there was also a significant association between a low baseline histologic activity index and a sustained response. These observations confirm the unfortunate paradox that the patients more in need of therapy because of a greatest risk for progressive disease are those least likely to respond to treatment. It emerges from our data that doubling the IFN dosage after an ineffective 3-month course of 3 MU provides a therapeutic gain in about 15% of patients. Although this rate seems disappointing, eight (73%) of the 11 patients who responded after increasing the dose maintained a sustained response, suggesting that some patients may obtain a permanent therapeutic advantage by escalating the dosage. In a previous study (35), Marcellin et al. showed that an escalating dosage induced a complete response in 17% of patients who did not respond to an initial 3 MU dosage of IFN; all of them relapsed after treatment withdrawal: this discrepancy may be explained by the short-term protocol (24 weeks) adopted by the French authors. A limiting factor of prolonged treatment is the cost; a 2-year course with 3 MU of IFN three times a week costs about US$ 10000, plus additional expenses for laboratory tests and control visits. If further studies adopting prolonged treatment regimens confirm the increased rate of sustained response, a cost/efficacy analysis will be strongly needed in order to assess whether this therapeutic approach is competitive compared with combined treatments (IFN+ribavirin, IFN+ ketoprofen) that are currently being studied for non-responders/relapsers but which also show interesting perspectives for naive patients.

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29.

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