| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
Department of Internal Medicine, Erasmus University Medical Centre Rotterdam, 3000 CA Rotterdam, The Netherlands
Address all correspondence and requests for reprints to: Sebastian J. C. M. M. Neggers, M.D., Erasmus University MC Rotterdam, P.O. Box 2040, 3000 CA Rotterdam, The Netherlands. E-mail: s.neggers{at}erasmusmc.nl.
| Abstract |
|---|
|
|
|---|
Objective: Our objective was to assess long-term efficacy and safety in a larger group of acromegalic patients after a period of 138 (35–149) wk [median (range)].
Design: PEG-V was added to high-dose SSA treatment in 32 subjects (13 females) who had not shown a normalization in serum IGF-I concentrations during SSA monotherapy. PEG-V dosage was increased until IGF-I concentration normalized. The maximal dose was 80 mg twice weekly.
Results: After dose finding, IGF-I remained within the normal range in all subjects with PEG-V administered once (n = 24) or twice (n = 8) weekly, on a total weekly dose of 60 (40–160) mg. Baseline IGF-I levels were positively correlated with the required dosage of PEG-V (r = 0.48; P = 0.006). PEG-V-dependent liver enzyme disturbances were observed in 11 (6 diabetic) subjects, of which symptomatic gallstones explained two cases. These liver enzyme disturbances were transient in all subjects without discontinuation or dose adaptation of PEG-V. In our series, diabetic patients had a 5.1 times (odds ratio) (confidence interval, 1.02–25.54; P < 0.05) higher risk for developing liver enzyme disturbances. These liver enzyme disturbances seemed to occur earlier. Pituitary adenoma size decreased in four patients. No increase in tumor size was observed in any of the patients.
Conclusion: Long-term combined treatment with long-acting SSA and (twice) weekly PEG-V for active acromegaly seems to be effective and safe. Patients with acromegaly and diabetes seem to have a higher risk of developing transient liver enzyme disturbances.
| Introduction |
|---|
|
|
|---|
A more recent medical treatment modality is the GH receptor antagonist pegvisomant (PEG-V). With daily injections of PEG-V, in more than 90% of patients a normalization of IGF-I can be achieved (14, 15). In addition, glucose metabolism is improved (12, 14, 16, 17, 18). On the other hand, PEG-V has to be administered daily, and in some patients it was at least unable to prevent tumor growth (19). Combination of SSA and PEG-V treatment seems to be an attractive option because tumor suppression is combined with GH receptor blockade. We previously reported that PEG-V, administered weekly in addition to long-acting SSA therapy was able to normalize serum IGF-I levels in 95% of subjects (20). Here we present the long-term follow-up efficacy and safety data in the same patients plus newly included acromegalic subjects up to 138 (35–149) wk [median (range)].
| Patients and Methods |
|---|
|
|
|---|
Patients were enrolled from a single center. All subjects [n = 32, 13 females; median age 52 (range 30–81) yr] had elevated IGF-I levels [56 (32–122) nmol/liter] despite 120 mg lanreotide Autogel (n = 22) or 30 mg octreotide LAR (10) monthly for at least 6 months before the start of this series. Baseline characteristics are presented in Table 1
. In our series, patients with a pituitary macroadenoma and compression of the chiasm were not treated with a combination of SSA and PEG-V.
|
All patients continued long-acting SSA therapy at monthly intervals and, on top of that, PEG-V was added weekly. Starting dose of PEG-V was 40 mg weekly. PEG-V dosage was adjusted until IGF-I was within the age-adjusted normal range. If IGF-I fell in the lowest quartile of normal, the PEG-V dosage was reduced. The intervals of dose adjustments were 6 wk until a controlled IGF-I was achieved twice. The subjects then visited our outpatient clinic every 12–16 wk. If a dose of at least 100 mg was required, patients divided the dosage in two (equal) parts and injected twice weekly.
IGF-I and other efficacy and safety data were assessed at these regular visits. Efficacy was assessed at the longest follow-up visit [138 (35–149) wk] for IGF-I, GH, glycosylated hemoglobin (HbA1c), fasting glucose, lipids, and a quality of life questionnaire, Patient-Assessed Acromegaly Symptom Questionnaire (15). IGF-I and GH concentrations were measured by immunometric assays (Diagnostic Products Corp., Los Angeles, CA). The IGF-I age-adjusted reference ranges were used (21).
Safety assessment included electrocardiogram, serum concentrations of alkaline phosphatase,
-glutamyltranspeptidase (
-GT), alanine aminotransferase (ALT), aspartate aminotransaminase (AST), lactate dehydrogenase, total bilirubin, and change in pituitary tumor volume. Tumor volume was assessed at baseline by magnetic resonance imaging, which was repeated every 6 months. Changes in pituitary tumor size were assessed by the same neuroradiologist.
Statistical analysis
Paired nonparametric data were analyzed with the Wilcoxons signed-rank test. The nonpaired data were assessed with the Mann-Whitney U test and cross-tables with the Fishers exact test. Statistical analyses of the data were performed by Prism version 5.00 for Windows (GraphPad Software, San Diego CA). Statistical significance was accepted at P < 0.05 (two-tailed). Data are expressed as median ± SD unless otherwise specified.
| Results |
|---|
|
|
|---|
Thirty-two patients with acromegaly were enrolled in this series. Normalization of serum IGF-I levels was achieved in all patients (Fig. 1
). The median IGF-I decreased from 56.00 ± 28.7 nmol/liter at baseline, on SSA monotherapy, to a lowest level of 17.85 ± 6.16 nmol/liter (P < 0.0001) during combined treatment. The PEG-V dose needed for normalization of IGF-I was 60 (40–160) mg weekly [median (range)]. This median dose is identical to the one we reported previously (20). Eight patients needed PEG-V twice weekly.
|
|
Quality of life, compared with baseline, was improved in any assessment during follow-up (P < 0.05). IGF-I correlated well with quality of life.
Safety
Transient elevated liver enzyme tests (TLET) were observed in 11 patients (34%) (Table 2
). Of these 11 subjects with TLET, six patients (55%) also suffered from DM. In our study, acromegaly patients with DM had a 5.1 times (odds ratio) (confidence interval, 1.02–25.54; P < 0.05) higher risk for developing TLET than nondiabetic subjects. We already reported on one diabetic patient who developed a transient drug-induced hepatitis due to which pegvisomant medication was stopped after 25 wk (22). Data of this patient are included in the safety data and baseline analyses. Subjects with DM also tended to have an earlier onset of TLET (21.0 ± 10.5 wk) than subjects without (25.0 ± 36.3 wk), although this was not significant (P = 0.178) (Fig. 3
). The duration of the TLET was the same in both DM (12.0 ± 6.1 wk) and non-DM (18.0 ± 11.5 wk).
|
|
In 28 subjects, no increase in size of the pituitary tumor was observed. In four subjects (13%), a regression in tumor size by more than 25% occurred. None of these four patients had received RT before enrollment in this series, whereas three subjects (9%) were on primary medical therapy and had been treated for 43, 45, and 73 wk with monotherapy SSA and for 74, 148, and 143 wk with combination therapy. The other subject had TSS 2 yr before enrollment and had been treated for 71 wk with monotherapy SSA and 143 wk with combination therapy.
| Discussion |
|---|
|
|
|---|
In 11 patients (34%), we observed TLET. Two patients had TLET due to gallstones probably related to the use of long-acting SSAs (20). Liver enzyme disturbances during daily PEG-V treatment, AST, and ALT are usually more elevated than
-GT and bilirubin (24). The more prominent elevation in
-GT and bilirubin led to the conclusion that in two patients, the TLET was caused by cholelithiasis. The majority of patients who developed TLET had DM. These patients have an odds ratio of 5.1 to develop TLET during combination treatment and also tended to develop TLET earlier compared with patients without DM, although this was not significant. Another study assessed TLET in 12 patients with daily PEG-V of whom two subjects were cotreated with monthly long-acting octreotide (30 mg) (24). The liver enzyme disturbances were not dose related and occurred after 15.7 ± 10.7 wk (mean ± SD). However, no association of a phenotypic predictor was found. The mechanism of PEG-V-induced TLET remains unclear. The reason why the DM acromegalic patients in our series develop TLET earlier and more frequently also remains the subject of conjecture. We could not find another predictor that could explain the TLET. Although in our patients we did observe elevated liver enzyme tests, we consider the combined treatment as a safe treatment option of acromegalic patients that do not respond enough to monotherapy with SSA, because these mild disturbances of liver enzymes are transient without discontinuation or dose adaptation of PEG-V. This is in contrast to some other studies in which PEG-V is withdrawn. A frequent assessment of liver enzymes, as already indicated by the package insert of PEG-V, seems mandatory, however, especially in patients with DM.
In our series, we did not observe tumor growth in any of the patients. Four subjects even showed a regression in tumor size by more than 25%. It is noteworthy that none of these subjects were previously treated with RT.
From our clinical experience, one starts with a weekly dose of 40 mg PEG-V, which can be increased by 20 mg every 6 wk until normalization of IGF-I has been achieved. In our hands, we need two to three steps of dose titration to normalize IGF-I in the majority of patients, achieving disease control within 3 months after starting combination therapy.
In conclusion, although more research is necessary in larger cohorts of patients, our series indicates that long-term combined treatment of active acromegaly with both long-acting SSA and (twice) weekly injections of PEG-V seems to be effective and safe, at least for those subjects in whom serum IGF-I remains elevated during SSA monotherapy. Transient and mild elevations in liver functions were observed in one third of patients, and especially diabetic patients seemed to be more prone to this side effect.
| Footnotes |
|---|
First Published Online September 25, 2007
Abbreviations: ALT, Alanine aminotransferase; AST, aspartate aminotransaminase; DM, diabetes mellitus;
-GT,
-glutamyltranspeptidase; HbA1c, glycosylated hemoglobin; PEG-V, pegvisomant; RT, radiotherapy; SSA, somatostatin analogs; TLET, transient elevated liver enzyme tests; TSS, transsphenoidal surgery.
Received June 4, 2007.
Accepted September 13, 2007.
| References |
|---|
|
|
|---|
This article has been cited by other articles:
![]() |
M Buchfelder, D Weigel, M Droste, K Mann, B Saller, K Brubach, G K Stalla, M Bidlingmaier, C J Strasburger, and on behalf of the investigators of the German Pegvi Pituitary tumor size in acromegaly during pegvisomant treatment: experience from MR re-evaluations of the German Pegvisomant Observational Study Eur. J. Endocrinol., July 1, 2009; 161(1): 27 - 35. [Abstract] [Full Text] [PDF] |
||||
![]() |
C E Higham, J D J Thomas, M Bidlingmaier, W M Drake, and P J Trainer Successful use of weekly pegvisomant administration in patients with acromegaly Eur. J. Endocrinol., July 1, 2009; 161(1): 21 - 25. [Abstract] [Full Text] [PDF] |
||||
![]() |
I. Bernabeu, J. Cameselle-Teijeiro, F. F Casanueva, and M. Marazuela Pegvisomant-induced cholestatic hepatitis with jaundice in a patient with Gilbert's syndrome Eur. J. Endocrinol., May 1, 2009; 160(5): 869 - 872. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Melmed, A. Colao, A. Barkan, M. Molitch, A. B. Grossman, D. Kleinberg, D. Clemmons, P. Chanson, E. Laws, J. Schlechte, et al. Guidelines for Acromegaly Management: An Update J. Clin. Endocrinol. Metab., May 1, 2009; 94(5): 1509 - 1517. [Abstract] [Full Text] [PDF] |
||||
![]() |
A. Pokrajac, J. Frystyk, A. Flyvbjerg, and P. J Trainer Pituitary-independent effect of octreotide on IGF1 generation Eur. J. Endocrinol., April 1, 2009; 160(4): 543 - 548. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. Neggers, W. de Herder, J. Janssen, R. Feelders, and A. van der Lely Combined treatment for acromegaly with long-acting somatostatin analogs and pegvisomant: long-term safety for up to 4.5 years (median 2.2 years) of follow-up in 86 patients Eur. J. Endocrinol., April 1, 2009; 160(4): 529 - 533. [Abstract] [Full Text] [PDF] |
||||
![]() |
S. J. C. M. M. Neggers, M. O. van Aken, W. W. de Herder, R. A. Feelders, J. A. M. J. L. Janssen, X. Badia, S. M. Webb, and A. J. van der Lely Quality of Life in Acromegalic Patients during Long-Term Somatostatin Analog Treatment with and without Pegvisomant J. Clin. Endocrinol. Metab., October 1, 2008; 93(10): 3853 - 3859. [Abstract] [Full Text] [PDF] |
||||
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Endocrinology | Endocrine Reviews | J. Clin. End. & Metab. |
| Molecular Endocrinology | Recent Prog. Horm. Res. | All Endocrine Journals |