537468

research-article2014

AOPXXX10.1177/1060028014537468Annals of PharmacotherapyWilhelm et al

Review Article-New Drug Approvals

Teduglutide for the Treatment of Short Bowel Syndrome

Annals of Pharmacotherapy 2014, Vol. 48(9) 1209­–1213 © The Author(s) 2014 Reprints and permissions: sagepub.com/journalsPermissions.nav DOI: 10.1177/1060028014537468 aop.sagepub.com

Sheila M. Wilhelm, PharmD1,2, Melissa Lipari, PharmD1,3, Janice K. Kulik, PharmD1,3, and Pramodini B. Kale-Pradhan, PharmD1,3

Abstract Objective:To review the pharmacology, pharmacokinetics, clinical efficacy, and safety of the newly approved drug, teduglutide, for the treatment of short bowel syndrome (SBS). Data Sources: Literature was retrieved through PubMed (1966-March 2014) using the search term teduglutide. The authors applied the filters Humans and English language, resulting in 47 publications. Study Selection and Data Extraction: The authors reviewed the 47 citations to extract those that were published clinical trials. Bibliographies of recent review articles and editorials were evaluated for additional pertinent publications for inclusion. The methods and results from each of the trials were extracted. Data Synthesis: Teduglutide has been studied in SBS in 3 phase III trials. Teduglutide decreases parenteral nutrition (PN) volume requirements, with 1 study showing a reduction of 4.4 ± 3.8 L/wk with teduglutide 0.05 mg/kg versus 2.3 ± 2.7 L/wk with placebo; P < 0.001. In another study, teduglutide improved graded response scores, which are based on the intensity and duration of the reduction of PN use (16/35 assigned to teduglutide 0.05 mg/kg vs 1/16 assigned to placebo; P = 0.007). The dosing range studies have indicated that the optimal dose of teduglutide is 0.05 mg/kg daily subcutaneously. There are a number of adverse effects reported in the trials, including abdominal pain or distention, injection site reactions, nausea, headaches, and fluid overload among others. There is also a concern for the development of malignancy with teduglutide, and therefore, it is not recommended in patients with active gastrointestinal malignancies. Conclusions: Overall, teduglutide appears to be a promising agent for the treatment of SBS. Keywords gastroenterology, adult medicine, biopharmaceutics, clinical practice, parenteral nutrition

Introduction Short bowel syndrome (SBS) is a disease state with reduced functioning small bowel length that can be congenital or acquired as a consequence of other disease states or surgery.1 SBS alters the absorptive capacity of the intestines relative to the length and portion of short bowel removed. Patients present with a heterogeneous mixture of symptoms, including diarrhea, steatorrhea, abdominal pain, malnutrition, and dehydration. The severity of symptoms depends on the length of small bowel remaining. The prevalence of SBS is not fully clear; however, there is an ongoing effort through a current United States registry to establish an accurate estimate.2 It has been reported that SBS is the primary reason that patients receive long-term home parenteral nutrition (PN).3 Home PN brings with it many complications, which may be infectious, metabolic, or practical. The presence of an indwelling intravenous catheter puts patients at risk for developing potentially life-threatening infections and could lead to practical complications such as catheter malfunction or venous thromboembolism. Metabolic complications of PN include electrolyte disturbances, bone mineral disease,

and liver disease. These complications can impair the overall quality of life. In light of potential long-term complications, treatments and procedures that are able to increase intestinal absorption and reduce reliance on PN would be expected to have a positive impact on the care of patients with SBS. Only supportive treatment options were available until 2012, when teduglutide, a glucagon-like peptide-2 (GLP-2) analog, became the first approved agent for the long-term treatment of SBS in adults.

Pharmacology Native GLP-2 is degraded to its inactive form by dipeptidylpeptidase IV (DPP-IV). Native GLP-2 affects 1

Wayne State University, Detroit, MI, USA Harper University Hospital, Detroit, MI, USA 3 St John Hospital and Medical Center, Detroit, MI, USA 2

Corresponding Author: Pramodini B. Kale-Pradhan, St John Hospital and Medical Center, 22101 Moross Road, Detroit, MI 48236, USA. Email: [email protected]

Downloaded from aop.sagepub.com at WAKE FOREST UNIV on August 21, 2014

1210

Annals of Pharmacotherapy 48(9)

the gastrointestinal (GI) tract’s growth and maintenance resulting in structural and functional adaptation. Structural adaptation includes lengthening of the intestinal villi and increasing crypt depth, resulting in increased surface area in the GI tract. Functional adaptation results from a slowing of GI transit, which allows for increased time for absorption of nutrients. Teduglutide is a 33-amino acid peptide and analog of GLP-2.4 It contains an amino acid substitution of glycine for alanine at position 2, which renders teduglutide resistant to degradation by DPP-IV. Teduglutide acts as a GLP-2 analog, binding to and activating GLP-2 receptors in the small intestine, thereby amplifying the native effects of GLP-2. This results in increased intestinal and portal blood flow, villi height, and crypt depth and inhibition of gastric acid secretion and gastric motility. Thus, teduglutide ultimately reduces intestinal losses and improves absorption.

Pharmacokinetics Teduglutide pharmacokinetics have been assessed in healthy individuals as well as in those with renal impairment. The bioavailability following a subcutaneous (SQ) injection is 88%.5 It has a volume of distribution of 103 mL/ kg. Teduglutide’s metabolism has not been elucidated in humans. It is thought that teduglutide would be degraded similarly to endogenous GLP-2 via catabolic pathways. Its elimination half-life is estimated to be 2 hours in healthy individuals and 1.3 hours in SBS patients. Teduglutide is renally eliminated. The effect of renal impairment on teduglutide’s pharmacokinetic profile has been assessed in 36 individuals with moderate to severe renal impairment and in those requiring dialysis who were matched and compared with patients with normal renal function.6 Depending on the degree of renal impairment, the mean elimination half-life values ranged from 1.4 to 2.2 hours, which was not different from what has been reported in healthy individuals. However, there was a 2.59-fold increase in the area under the curve and 2.08-fold higher peak plasma concentrations in patients with renal impairment or end-stage renal disease when compared with healthy individuals. These findings support a 50% reduction in dose in patients with moderate to severe impairment.

Clinical Trials The available trials are summarized in Table 1.7-12 Two open-label phase II clinical trials investigated the effect of teduglutide in patients with SBS. The methodology and results of these studies have previously been described in detail.3 Both the phase II trials resulted in increases in villus height and crypt depth within the small intestine, measured by microscopic evaluation of intestinal biopsy samples,

indicating an increase in intestinal surface area and potential for increased intestinal absorption.7,8 One of the phase II trials also examined intestinal absorption.8 Results showed that intestinal absorption increased during 72-hour balance periods when nutrient intake and urine and fecal excretion was quantified based on significant increases in wet weight absorption and urine production and reductions in fecal wet weight excretion. Because these were open-label trials, their results led to continued investigation of teduglutide’s efficacy and safety through phase III randomized, placebo controlled trials. In the first phase III trial, 83 patients with SBS were randomized to receive SQ teduglutide 0.10 or 0.05 mg/kg/d, or placebo daily for 24 weeks.9 The study’s primary efficacy end point was a graded response score, defined by intensity and duration of response. The intensity and duration of the response was scored based on a combination of the reduction in PN volume from baseline at weeks 16 to 20 and 20 to 24. Teduglutide 0.10 mg/kg was not statistically different when compared with placebo in the graded response score; however, the 0.05-mg/kg dose showed a significant effect (P = 0.007). Secondary end points of villus height, plasma citrulline concentration, and lean body mass were significantly increased with teduglutide compared with placebo. There was a trend toward higher baseline PN volume in the 0.10-mg/kg/d group compared with the 0.05-mg/kg/d group (1816 ± 1008 vs 1374 ± 639 mL/d, P = 0.11). A larger baseline PN volume may have blunted the response seen in the 0.10-mg/kg/d group compared with the group receiving 0.05 mg/kg/d. This may contribute to the explanation of why the lower dose was statistically effective when compared with placebo but the higher dose was not. The rates of adverse effects were similar in all 3 arms of the study, ranging from 94% to 97%. Two patients in the teduglutide 0.10-mg/kg group, 5 patients in the 0.05-mg/kg group, and 1 patient in the placebo group discontinued treatment as a result of an adverse event. Additionally, 1 patient in the 0.10-mg/kg/d group and 3 patients in the 0.05mg/kg/d group decided to discontinue treatment. In another phase III trial, which was an extension of the previous trial, 52 patients with SBS continued with the same teduglutide dose that they were randomized to in the previous study (0.05 or 0.10 mg/kg daily) and were followed for an additional 28 weeks, for a total treatment period of 52 weeks.11 The primary end point in this study was a 20% or more reduction in PN volume at week 52. This end point was seen in 68% of the 0.05-mg/kg/d and 52% of the 0.10-mg/kg/d dose group. A reduction of 1 or more days of PN dependence was observed in 68% of the 0.5-mg/kg/d group and 37% of the 0.10-mg/kg/d group. Overall, 96% of patients reported adverse effects, which was similar in both arms of the study. In the final phase III trial, 86 patients with SBS with intestinal failure were randomized to SQ teduglutide 0.05

Downloaded from aop.sagepub.com at WAKE FOREST UNIV on August 21, 2014

1211

Wilhelm et al Table 1.  Teduglutide Clinical Trials in Short Bowel Syndrome: References.7-12 Author, Year

Design

n

Intervention

Results

Tappendenet al, 2002, phase II  

P, R

11

Teduglutide 0.03 mg/kg/d, 0.1 mg/ kg/d, or 0.15 mg/kg/d for 21 days

Jeppesen et al,8 2005, phase II

OL

18

Teduglutide 0.03 mg/kg/d, 0.1 mg/ kg/d, or 0.15 mg/kg/d for 21 days once or twice daily

R, PC

83

Teduglutide 0.10 mg/kg, 0.05 mg/ kg, or placebo daily ×24 weeks

R, DB, PC

86

Teduglutide 0.05 mg/kg vs placebo once daily ×24 weeks

R, DB, PC

52

Teduglutide maintained on 0.05 or 0.10 mg/kg daily ×52 weeks

OL

37

Body mass index and PN volume 12 months after discontinuation of ≥24 weeks of teduglutide

Increase in villus height (P = 0.005) regardless of doses Increase in crypt depth at 0.03 and 0.1 mg/kg dose (P = 0.03) Increase in absolute weight (743 ± 477 g/d, P < 0.001) Increase in relative wet weight absorption (22% ± 16%, P < 0.001) Increase in urine weight (555 ± 485 g/d, P < 0.001) Increase in urine sodium excretion (53 ± 40 mmol/d, P < 0.001). Decrease in fecal wet weight (711 ± 734 g/d; P = 0.001) and decrease in fecal energy excretion (808 ± 1453 kJ/d, P = 0.040). SBS patients with end jejunostomy Increase in villus height (38% ± 45%, P = 0.030) Increase in crypt depth (22% ± 18%, P = 0.010) Mitotic index (+115% ± 108%, P = 0.010) Teduglutide 0.10 mg/kg vs placebo (GRS 8/32 vs 1/16, P = 0.16). Teduglutide 0.05 mg/kg vs placebo (GRS 16/35 vs 1/16 P = 0.007) Mean reduction in parenteral support volume (4.4 ± 3.8 L/wk vs 2.3 ± 2.7 L/wk; P < 0.001). ≥1-Day reduction in weekly need for parenteral support (54% teduglutide vs 23% placebo, P = 0.005) >20% Reduction in PN: 68% of the 0.05-mg/ kg/d and 52% of the 0.10-mg/kg/d groups Reduction of ≥1 of PN dependence in 68% of the 0.5-mg/kg/d and 37% of the 0.10-mg/ kg/d groups Patients had shorter colons, less frequently in INC PN group vs UC/DEC PN group BMI decreased at 3, 6, and 12 months, P = 0.001 in INC PN group relative to first off-drug visit No change in BMI relative to first off-drug visit in UC/DEC PN group

7

             

  Jeppesen et al,9 2011, phase III   Jeppesen et al,10 2012, phase III   O’Keefe et al,11 2013, extension of Jeppesen, 2011, additional 28 weeks, phase III   Compher et al,12 2011    

Abbreviations: R, randomized; OL, open label; SBS-IF, short bowel syndrome with intestinal failure; P, Prospective; PC, placebo controlled; GRS, grades response score; DB, double blind; PN, parenteral nutrition; INC, increased; UC/DEC, unchanged/decreased; BMI, body mass index.

mg/kg or placebo once daily for 24 weeks.10 The primary end point in this study was a 20% or more reduction in PN volume at week 20, which was maintained at week 24. Significantly more patients achieved the primary end point in the teduglutide group compared with placebo (63% and 30%, respectively; P = 0.002). The overall and treatment emergent adverse events were comparable between the groups (treatment emergent adverse events, 36% vs 28% in teduglutide and placebo groups, respectively).

To evaluate the lasting effects of teduglutide, the changes in PN volume and body mass index for 12 months were investigated in 37 patients after discontinuation of ≥24 weeks of teduglutide therapy.12 Patients were classified into groups with increased weekly (INC) PN volume or unchanged/decreased (UC/DEC) PN volume. Patients who had INC PN volume had shorter colons and less frequently had colon in continuity when compared with patients with UC/DEC PN volume. BMI was decreased at 3, 6, and 12

Downloaded from aop.sagepub.com at WAKE FOREST UNIV on August 21, 2014

1212

Annals of Pharmacotherapy 48(9)

months relative to the first off-drug visit in patients with INC PN (P = 0.001) but not in the UC/DEC PN volume patients. Change in BMI off-drug was predicted by colon and small bowel length, baseline BMI, and on-drug change in PN volume. This trial indicates that there is ongoing benefit even after discontinuing teduglutide especially in patients who were able to reduce PN volumes on teduglutide therapy. There are several limitations to these trials. The trials used different end points, which makes it difficult to compare results. The studies also used different time frames for the end points. Also, the trials that reported decreases in the need for PN used slightly different algorithms based on urine output to determine the PN volume titrations. The trials enrolled a relatively small number of patients, although it may be challenging to find and recruit large numbers of patients with SBS who require PN.

were found at a low frequency overall: teduglutide 0.05 mg/ kg/d, 3.1% to 6.3%; teduglutide 0.10 mg/kg/d, 3.3%; and placebo, 6.7% to 13.3%. From all clinical trials, 3 individuals were diagnosed with malignancy, all of whom were male and had received teduglutide 0.05 mg/kg/d. One patient had a history of abdominal radiation for Hodgkin’s disease 2 decades before receiving teduglutide. The patient also had a prior liver lesion and was diagnosed with metastatic adenocarcinoma of unconfirmed origin after 11 months of exposure to teduglutide. Two others had extensive smoking histories and were diagnosed with lung cancers after receiving teduglutide for 3 and 12 months. Teduglutide is not recommended in patients with active cancer of the GI tract; however it may be considered in those who have non-GI malignancy if benefits outweigh the risks.

Economic Considerations

Dosage Recommendations The FDA has approved teduglutide at a dose of 0.05 mg/kg body weight once daily subcutaneously.5 In patients with creatinine clearance

Teduglutide for the Treatment of Short Bowel Syndrome.

To review the pharmacology, pharmacokinetics, clinical efficacy, and safety of the newly approved drug, teduglutide, for the treatment of short bowel ...
282KB Sizes 2 Downloads 3 Views