Better HCV Treatments Approved

Both Simeprevir and Sofusbuvir have been approved unanimously by FDA panel.

Excerpt from AP report on simeprevir  (full link: ow.ly/qarKM from AGA twitter feed):

All 19 members of the Food and Drug Administration’s panel of virus experts voted in favor of approving J&J’s simeprevir, a daily pill designed to eliminate the most common form of hepatitis C.  The FDA is not required to follow the group’s recommendations, though it often does. A decision on the drug is expected next month.

Roughly 3.2 million people in the U.S. have hepatitis C, a blood-borne disease that causes liver damage and is blamed for 15,000 deaths a year…

New Brunswick, N.J.-based J&J is seeking approval to combine its pill with the long-established drug cocktail used to treat the most common form of the virus.

Despite the unanimous vote Thursday, the panel’s endorsement came with a number of conditions.

The panelists stressed that the drug is less effective in patients with a common genetic mutation called Q80K, and that people with the abnormality should be screened out so they can receive other drugs. The group also said the drug’s label should warn patients and doctors that sunburn is a common side effect. Finally, panelists said that the FDA should require J&J to conduct additional studies of the drug’s effectiveness in minorities, especially African-Americans who are disproportionately infected…

The FDA meeting comes as federal health officials urge all baby boomers to get tested for the virus…

J&J’s simeprevir appears to be slightly more effective than the standard of care, curing 80 percent of patients who had not previously been treated for the disease, according to studies submitted to the FDA. More significantly, the drug helped most patients cut the amount of time they had to take the traditional drug cocktail, with its unpleasant side effects, to six months rather than one year. Additionally, panelists said the drug’s once-a-day dosage should be far more manageable for patients than the current drugs from Merck and Vertex, which require taking 12 pills or six pills a day, respectively.

And for Sofusbuvir from Reuters (FDA panel backs Gilead hepatitis C drug sofosbuvir)

The FDA advisory panel voted 15 to 0 in favor of approval of the drug in patients with two variants of the liver-damaging disease – genotype 2 and genotype 3 – in combination with an existing treatment, ribavirin.

If approved, it will be the first all-oral treatment for genotypes 2 and 3, obviating the need for the injectable drug interferon, which can cause debilitating side effects. Panelists called the vote “historic” and a “game-changer.”

“Our patients have been waiting for this for a long time,” said Dr. Curt Hagedorn, chief of medicine service at the Central Arkansas Veterans Healthcare Service.

The panel also voted unanimously to approve the drug in patients with genotype 1 and genotype 4 variants in combination with ribavirin and interferon in patients who have not received prior therapy.

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A C difficile two-fer

Two recent review articles on Clostridium difficile are quite useful:

  • Mezoff EA, Cohen MB. J Pediatr 2013; 163: 627-30.
  • Dupont HL. Clin Gastroenterol Hepatol 2013; 11: 1216-23.

The first publication reviews acid suppression and the risk of C difficile infection (CDI).  It starts off with  a terrific piece of advice from Sir William Osler: “One of the first duties of the physician is to educate the masses not to take medicine.”  The authors note that pH above 4 has been shown to increase bacterial survival, including  C perfringe spores in a mouse model.  In addition, the article notes that there have been concerns as early as 1982 that acid suppression could be a risk factor for CDI.  Several recent studies were summarized, including the following:

  • A recent meta-analysis (Kwok CS et al. Am J Gastroenterol 2012; 107: 1011-9) with 42 studies (N= 313,000 patients) “found an association between PPI use and risk of CDI (OR1.74, 05%CI 1.47-2.85).”
  • A review of the literature (Deshpande A et. Clin Gastroenterol Hepatol 2012; 10: 225-33) between 1990-2010 found an overall increase in CDI risk with PPIs to be OR 2.15 (95% CI 1.81-2.55). No prospective studies were identified.
  • In pediatrics, a study (Turco et al. Alimentary Pharmacol Therapeut 2010; 31: 754-9) with 910 children admitted for abdominal pain and diarrhea identified 68 with CDI.  Compared with control patients, use of PPIs was significantly higher in CDI patients (OR 4.52, 95% CI 1.4-14.4).

The FDA has stated that PPIs may be associated with an increased risk of CDI.  In addition, the use of antibiotics “appear to act synergistically with PPIs.”  Thus, the authors recommend stopping PPIs in those who do not need them.  Periodic ‘holidays’ or dosing step-downs may help assess continued need for PPIs.

The second publication succinctly reviews the diagnosis and management of CDI.  The various diagnostic methods are compared in Table 1.  Therapeutic options for 1st time infection are reviewed in Table 2.  For adults with mild-to-moderate infections, metronidazole (500 mg TID for 10 days) is preferred.  Vancomycin or Fidaxomicin are recommended for more severe infections.

Table 3 lists treatment options for recurrent CDI.  Repeat course of any of the 1st round treatments can be considered depending on patient’s illness severity.  In addition, other potential treatments included the following:

  • vancomycin tapered dose (week 1: 125 mg 4 times/day, week 2: 125 mg 2 times/day, week 3: 125 mg once/day, week 4: 125 mg every other day, week 5 & 6: 125 mg every third day)
  • rifaximin (550 mg BID x 20 days)
  • high-dose vancomycin (250-500 mg 4 times/day for 10 days) followed by S boulardii (2 capsules BID for 28 d)
  • fecal microbiota transfer (FMT) –“although family member stool donors have been used, the current movement is toward volunteer donor pools.”  [I do not think ‘current movement’ was intended as a pun by the authors.]  Volunteer donors could lower the screening costs.
  • intravenous immunoglobulin (small clinical trials have failed to show efficacy)
  • monoclonal antibodies to toxins A/B

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One More Day Syndrome & Necrotizing Enterocolitis

In many situations, the advice is to wait one more day and then decide/act; however, sometimes one more day winds up being a week, a month, or longer.  A recent editorial indicates that there is enough evidence now for probiotic usage in neonates to prevent necrotizing enterocolitis (NEC).  The authors state that to continue “with the standard of care, in which no new products are provided…is ethically unacceptable” (JAMA Pediatrics 2013; 167: 885-6).  Thanks to Ben Gold for this reference.

Key arguments:

  • A 2011 Cochrane review identified 16 eligible trials with 2842 premature infants (<2500 g, <37 weeks).  Probiotics reduced the incidence of NEC with a relative risk of 0.35 and mortality with a relative risk of 0.40.  Despite the typically cautious recommendations from Cochrane reviews, the authors state “updated review of available evidence supports a change in practice.”
  • While the American Academy of Pediatrics in 2010 noted there is some evidence to support probiotic usage and called for more studies, there are no studies currently being conducted in the U.S.
  • The authors note that the “FDA Center for Biologic Evaluation and Research is committed to policies that effectively prohibit probiotic efficacy trials.” Under current policies, the authors state these “studies will not be conducted in a US setting for the next 20 to 30 years.”
  • Other countries , like Australia, allow use of probiotic with parental consent.
  • The authors propose that probiotic efficacy be studied in a comparative effectiveness design.

Bottomline: Current regulations have stymied the use of probiotic trials for NEC.  What will it take for regulatory agencies to relent and allow this promising research?

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Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) and specific medical management interventions should be confirmed by prescribing physician.  Application of the information in a particular situation remains the professional responsibility of the practitioner.

Civet Cat Poop Coffee

From KT Park’s twitter feed: npr.org/blogs/thesalt/2013/09/02/218232266/is-your-pricey-cup-of-cat-poop-coffee-fake-there-s-a-test-for-that …

Dr. Balistreri briefly referred to civet cat poop coffee in his clinical year in review of studies.  This year’s focus was on the microbiome.  The lecture pulled together a large number of divergent sources to show how the microbiome can affect everything, including inflammatory bowel disease, colic and obesity.  The reference to Civet Cat poop coffee indicates that ingesting stool may not be as disgusting as it sounds.

Top Lecture: Enteral Nutrition for Crohn’s Disease

In my opinion, the best lecture from this year’s postgraduate course was from Dr. Baldassano.  Enteral nutrition in Crohn disease: Where should this be in our treatment algorithm?  Robert N. Baldassano, MD (page 115)

Dr. Baldassono has personal experience with improving with enteral therapy after failing methotrexate/remicade.  His conclusion:

Enteral Nutritional Therapy: Where should this be in our treatment algorithm?

  • Should be offered to all newly diagnosed Crohn’s patients who can tolerate Nutritional Therapy
  • Special groups (especially a good idea): Malnourished patients, Younger patients, Growth failure, History of Cancer, Family history of Lymphoma, Consider when failing other therapies

This conclusion is supported by his presentation.

Should we be immunosuppressing our Patients?  Hypothesis: IBD arises from inappropriate handling of intestinal bacteria

Elements of Modern Lifestyle Lead to Changes in Gut Microbiota

  1. Improved sanitation
  2. Less crowded living conditions
  3. Decline in parasites
  4. Vaccinations
  5. Increased antibiotic use
  6. Caesarean section
  7. Refrigeration
  8. Food processing
  9. Diet changes
  10. Improved sanitation

Diet is associated with new onset IBD

  • High dietary intakes of total fats, PUFAs, omega‐6 and meat were associated with an increased risk of CD and UC
  • High fiber and fruit intakes were associated with decreased CD risk
  • High vegetable intake was associated with decreased UC risk.  Reference: Hou JK et al. American Journal of Gastro 2011; 106:563-73
  • The Bacteroides enterotype highly associated with animal protein and saturated fats which suggests meat consumption as in a Western diet
  • The Prevotella enterotype, high values for carbohydrates and simple sugars, indicating association with a carbohydrate-based diet, more typical of agrarian societies.  References: Wu G, et al. Science. 2011 Oct 7;334(6052):105‐8

Partial or Complete Enteral Nutrition?

  • 50% vs 100% of total caloric needs for induction with elemental formula (PCDAI < 10 at 6 weeks)
  • 50% of total caloric needs 15% remission
  • 100% of total caloric needs 42% remission
  • Labs improved only in the 100% group
  • Weight gain similar in the 2 groups. References: Akobeng et al Clin Nutr 2007; Ludvigsson et al Acta Paediatr 2004;Johnson et al Gut 2006;Critch et al. JPGN: 2012 

Pediatric Longitudinal Study of Semi‐Elemental Diet and Stool Microbiome (PLEASE)

Prospective cohort study of children with Crohn disease from Philadelphia (used Peptamen), Toronto (used Modulen) and Halifax (used Osmolite); (n=90)

  • Enteral therapy with defined formula diet (n=38) vs. anti‐TNFα therapy (n=52)
  • Similar drop in PCDAI and calprotectin in TNF group and diet group. 

Other points:

  1. Insurance generally will cover nasogastric feeds
  2. Disease location –not clear that this matters with Crohn’s disease
  3. The reason EN works may be not what you are giving the patient but what the patient is not getting
  4. Bacterial populations in pediatric IBD subjects on semi‐elemental diet (16S rDNA sequencing) develop a rapid change in gut bacterial populations upon initiating diet.
  5. Partial (50%) nutrition, as noted above, helped maintain remission compared to normal diet.

Nutrition Therapy: “European” Protocol

• Induction:  Exclusive enteral nutrition with an elemental, semielemental,or polymeric formula

• Duration: 4 – 12 weeks

• Maintenance Therapy: (either)

– Nutritional therapy: Repeat 4 week cycle of exclusive enteral nutrition every 3– 4 months

OR

– Medical therapy: 6‐MP/AZA/MTX after induction with nutritional therapy

CHOP EN Experience: What if >80% of calories is from Enteral Nutrition?

  • Methods: Semi‐elemental formula, 80%‐90% of patient’s caloric needs from formula, Nocturnal NG feeds (outpatient teaching program), Normal diet as tolerated during the day
  • Duration:  7 days per week for 8‐12 weeks (induction), 5 days per week (maintenance) Reference: Gupta et al. Inflamm Bowel Dis. 2013:1374-8.
  • Induction of remission: 65% (at 8 weeks)
  • Response: 87% (at 8 weeks)
  • Significant improvement in weight and linear growth
  • Protocol is well tolerated:  no serious adverse events

Postgraduate Course Syllabus (posted with permission): PG Syllabus

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Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) and specific medical management interventions should be confirmed by prescribing physician.  Application of the information in a particular situation remains the professional responsibility of the practitioner.

“Gluten-Related Disorders” (Part 2)

Non-celiac Gluten Sensitivity NCGS -Focused discussion in Section III
  • No biologically measurable response has been found – these are people with normal celiac serology (neg ttg/ema) and normal biopsies.
  • Specific discussions regarding autism and schizophrenia.  On page 44, authors note that a 2008 Cochrane review concluded the evidence for a gluten-free diet for autism was poor.  In 2012, a two-stage RCT (Whiteley et al) of gluten-free casein-free diet reported significant group improvements after 8 and 12 months on diet. Thus, diet may be helpful.
  • Other chapters allude to NCGS as well.  Page 124: “There are no epidemiologic studies assessing the prevalence of NCGS. Bizzaro et al estimated that for every one person with CD, there are at least six to seven with gluten sensitivity.”
Wheat Allergy -Section IV
  • Forms include oral food allergy, “wheat-dependent, exercise-induced anaphylaxis,” and Baker’s asthma (aerosolized exposure).
  • Skin prick tests or RAST’s are notorious for providing a high rate of false-positive results.  Low rate of false negative results, though, are noted.

Treatment -Section VI:

  • This section provides a number of tables to assist with diet and hidden sources of gluten.
  • GFD may lead to specific nutrient deficiencies: fiber, iron, folate, niacin, zinc, vitamins B12, A, D, E, and K; also, GFD may be higher in fat.

Psychological Aspects -Section VII:

 “The family has to buy gluten-free foods and all members have to learn how to avoid contaminating gluten-free foods, dishes, toasters, and so on.” Parents have to read all food labels and prepare special meals while attending social events.
A nice sample letter is included on page 129 –should make a good EPIC smartphrase.
Difficult Cases -Section VIII:
  • Labs to check in sick CD patient (Table 2 -page 133).
  • Causes of Nonresponse to GFD: poor compliance, accidental ingestions, nonceliac disease causing symptoms.
  • While some of the authors state that true refractory disease is “rare in adults,extremely rare in children,” in other parts of the book it is noted that complete histologic response is not seen in all patients (some with apparently good adherence).

IgA deficiency (page 139).

  • 85-90% of IgA deficient patients have no clinical symptoms.  Occurs in about 1 in 300.  For those with symptoms, manifestations could include sinopulmonary disease, allergy/atopy, autoimmune diseases, giardiasis/infections, and transfusion reactions (against IgA) (see Table 8 on page 143).
  • Transiently low IgA is common in children <4 years.
  • For IgA deficient patients, risk of CD is 10-20 times general population.
  • In true deficiency, level is typically <7 mg/dL.  More often, there is a partial deficiency which is ‘almost always asymptomatic.’  In partial IgA deficiency, IgA assays identify about 90% of CD cases.
Also, in the difficult cases section an algorithm for follow-up of newly diagnosed CD is presented and discussed (page 154).  Recommendations include nutritional counseling, resource identification, family screening, and celiac education.  Consider checking iron status, vitamin D, folate, zinc, copper and DEXA.  Recommends followup serology 6 months following diagnosis and if normal, then on a yearly basis.
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Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) and specific medical management interventions should be confirmed by prescribing physician.  Application of the information in a particular situation remains the professional responsibility of the practitioner.

“Gluten-Related Disorders” (Part 1)

On the way back from our National Meeting (NASPGHAN), I had the opportunity to read “Gluten-Related Disorders” ed. by Alessio Fasano.  The book is a very good summary about the science of celiac disease (CD), wheat allergy, and nonceliac gluten sensitivity (NCGS); at the same time, there is some redundancy due to multiple authors (particularly evident in later chapters). One of the book’s features is clinical vignettes to drive home multiple teaching points.  For example, the ‘refractory’ CD patient who in fact has Crohn’s disease. The book also provides a code to obtain the information online, so it is fully searchable.  In the introduction, there is an in-depth explanation of why gluten can be so difficult for the GI tract.  The discovery that a gluten-free diet can be helpful was a byproduct of wheat shortages during WWII.  Here are some useful insights that were noteworthy:

Definitions (page 9):  reviews the terms “silent CD,” “potential CD,” and “latent CD.”

  • Silent =asymptomatic but with all other features: +antibodies, +HLA type, +abnl histology
  • Potential =+antibodies but lack of histology evidence  (antibodies often precede development of clinical disease)
  • Latent =previous evidence of CD but currently tolerating gluten in diet with normal histology

Epidemiology:

  • While increase in CD is partly due to awareness, there has been a “true increase in prevalence, with rates doubling every 20 years or so.”
  • Early vaccinations are not risk factors for the development of CD
  • Breastfeeding can reduce risk of CD by about 50% though gluten should be introduced between 4-6 months.

Presentation:

  • Table of the main extraintestinal manifestations on page 24.  Most common: anemia (especially iron deficiency), short stature, and pubertal delay.
  • Associated diseases (Table 3, page 29): Down syndrome, Turner syndrome, Type I Diabetes, Williams syndrome, IgA deficiency, and Autoimmune thyroid disease.
  • Eosinophilic esophagitis has been identified in a small number of patients with celiac disease.  The book notes a study with 7 pediatric patients; only one of them improved their esophageal eosinophilia with a GFD.

Tips on diagnosing celiac

  • Bulb abnormalities with a normal 2nd portion of duodenum biopsy can be seen in 10% or more of patients with celiac.  The authors recommend obtaining 4 biopsies from 2nd and 3rd portion and 2 biopsies from bulb (separate containers) (page 144-145).
  • Most celiac experts say there is no celiac without DQ2 or DQ8.  There are several situations in which a negative HLA type could be helpful (page 78)
  1. -negative serology but abnormal histology
  2. -gluten-free diet (GFD) started before diagnosis confirmed
  3. -failure to respond to GFD
  4. -asymptomatic high-risk individuals to help determine if periodic serology is worthwhile
  • In most individuals, obtaining TTG IgA along with serum IgA is recommended for diagnosis (and avoiding older gliadin antibody tests).  If clinical suspicion is high, endoscopy is warranted regardless of result.
  • Under the age of 2, deamidated anti-gliadin antibodies appear months earlier than the TTG in prospective studies, so order the dAGA IgG and dAGA IgA in kids under 2. (Available with both quest and labcorp).  The deamindated anti-gliadin antibodies may be more helpful/sensitive in monitoring dietary adherence than TTG.
  • Infants who have a first degree family member with celiac should be introduced to “small” amounts of gluten between 4 and 6 mos of age – not before and not delayed.  It appears to promote tolerance though it’s not clear if it just delays inevitable onset.  Small amounts can be a serving a day of a mixed, barley baby cereal.
  • Section V is devoted to diagnosis.  Table 1 (page 72) lists the sensitivity/specificity of the available serologies.
  • Screening asymptomatic persons.  The controversy regarding this practice is alluded to on page 75.  Currently NASPGHAN recommends screening at risk groups whereas AGA does not.
  • Endoscopy/Biopsy discussed (pages 78-82).  States a biopsy is not needed in the case of dermatitis herpetiformis due to characteristic deposits of IgA in the dermal papilla.  The authors recommend biopsy in all cases, but review ESPGHAN guidelines which state that biopsy can be omitted if TTG IgA >10 time ULN –if verified by positive EMA, HLA typing, and followed for symptomatic improvement.
  • Antibody tests “become negative in 15% after 1 month on GFD and in 57% after 3 months…diagnosis of CD cannot be made while on GFD.”  Algorithm for diagnosis of CD with a child on GFD presented on page 148.
Related blog links:

Disclaimer: These blog posts are for educational purposes only. Specific dosing of medications (along with potential adverse effects) and specific medical management interventions should be confirmed by prescribing physician.  Application of the information in a particular situation remains the professional responsibility of the practitioner.

Nexium versus Fluticasone for EoE

As noted in previous blog posts (EoE: Drugs, Diets, Dilatation and PPI-REE | gutsandgrowth, EoE –Journal Club (Part 1) | gutsandgrowth, and EoE –Journal Club (Part 2) | gutsandgrowth), proton pump inhibitors are recommended as 1st line therapy in suspected eosinophilic esophagitis (EoE) for several reasons.  Besides the potential for gastroesophageal reflux to cause esophageal eosinophilia, there has been recognition of PPI-responsive eosinophilic esophagitis (PPI-REE).  In adults, the response to proton pump inhibitors, both clinically and histologically, is likely higher than in children; nevertheless, in children it is anticipated that 20-40% of patients with suspected EoE will have a histological remission with PPI therapy.

A recent study in adults suggests that PPIs may in fact outperform topical steroids (Am J Gastroenterol 2013; 108: 366-72).  Thanks to Ben Gold and Seth Marcus for identifying this reference.  This study enrolled 42 patients: 90% male, 81% white, mean age 38 years. It was a prospective single-blinded, randomized controlled trial with newly suspected EoE; half of the patients received esomeprazole 40 mg daily and half fluticasone swallowed aerosol 440 mcg twice a day.  After 8 weeks, all patients had repeat endoscopy; a total of eight biopsies were obtained –four at two locations: 15 cm above LES and 3 cm above LES.  In addition, at the start of the study, patients also underwent 24-h pH/impedance monitoring.  4 of the 21 patients in each group had abnormal degrees of gastroesophageal reflux/gastroesophageal reflux disease (GERD).

Study characteristics note that 62% of patients had coexisting atopic disorders.

Results:

  • There was no significant difference in esophageal eosinophilia response with 19% of the fluticasone and 33% of the esomeprazole achieving an eosinophil count < 5/hpf (P=0.484)
  • In patients with coexisting GERD, all 4 esomeprazole patients achieved histologic remission  compared with none of the fluticasone-treated patients.
  • When the GERD patients were excluded, the histological remission was quite similar: 24% with fluticasone and 18% for esomeprazole.

Overall, this study population had a lower rate of response to topical steroids than in multiple previous studies.  More typically, response rates of ~50% have been reported; however, studies have shown lower responses in some adult studies.  Variability in response could be related to multiple factors included dosage, duration, delivery, and definition of response.  In addition, population characteristics included disease duration and frequency of underlying atopic disease and GERD play a role.

Take-home points: Although this is a small study, it reinforces the fact that PPIs induce a histological response and clinical response in some patients suspected of having EoE regardless of whether GERD is present.  PPIs are considered 1st line therapy.  Topical fluticasone had a lower response rate in this study.  However, in clinical pediatric practice, topical steroids are effective in about 50% of patients.

Additional related blog entries:

Crohn’s Research: Going to Pot

A recent pilot study using Cannabis for Crohn’s disease is certain to attract a lot of attention (Clin Gastroenterol Hepatol 2013; 11: 1276-80).  The side effects are definitely less frightening than many of the accepted treatments.

Background: Cannabis has a long record of medicinal uses; it contains more than 60 different compounds, though Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) are thought to be the most active.  Cannabis has known antiinflammatory properties and has been shown to reduce colitis in a mouse model.

Study design/characteristics: 21 of 51 screened patients participated; these patients had active Crohn’s disease despite thiopurines in 20  or 21 and anti-tumor necrosis factor (TNF) therapy in 18.  These 21 patients were enrolled in a double-blind, placebo-controlled study.  The average age in the cannabis group was 46 years compared with 37 in the placebo group.  Both groups received cigarettes twice daily; the cannabis cigarettes had 115 mg of THC whereas the placebo group had cannabis flowers in which the THC had been extracted.  Though this was a double-blind study and efforts were made to mask the psychotropic effects by recruiting patients naive to cannabis, nevertheless, by the end of the study most of the patients knew whether they were in the active group or the placebo group.

Results:

  • Cannabis group had a 45% remission rate (5 of 11) with a CDAI of ≤150; the placebo group had a 10% remission rate.  This did not achieve statistical significance.
  • The response rate (CDAI drop of >100) was noted in 90% (10 of 11) of cannabis group compared with 40% in the placebo group.
  • The mean CDAI reduction was 177 in the study group compared with 66 in the placebo group (P= .005).
  • There were no significant laboratory changes (eg. Hgb, CRP, LFTs, kidney function).
  • No significant side effects were noted.  The study group reported less pain, improved appetite, and better satisfaction with their treatment.

In their discussion, the authors note that this is a small study.  They chose the smoking route with THC-rich cannabis to achieve higher blood levels, but note that oral dosing may be effective.  The 8-week duration of the study and lack of more objective markers of response precludes firm conclusions.

Take-home message: Cannabis should be studied further for its potential role in controlling inflammation.  This study’s timing will increase the broader interest in medical marijuana applications.

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Thiopurines = Low Efficacy for Crohn’s

The enthusiasm for thiopurine therapy for Crohn’s disease (CD) had already dropped a lot before two pivotal articles were recently published that confirmed the modest efficacy:

  • Cosnes J, et al. Gastroenterol 2013; 145: 758-65
  • Panes J, et al. Gastroenterol 2013; 145: 766-74
  • Gastroenterol 2013; 145: 714-16 (editorial)

The Cosnes study (from the GETAID group) reports an open-label randomized trial in 147 adult patients with newly diagnosed CD (from 2005–>2010) and risk factors for disabling disease who were recruited from 24 French centers.  Risk factors for disabling disease:

  • Age <40 years
  • Active perianal lesions
  • Corticosteroid use within 3 months of diagnosis

The characteristics and Paris classification are detailed in the paper’s Table 1. Patients were divided into early azathioprine or “conventional” treatment. Patient’s were followed for 3 years.  Azathioprine was dosed at 2.5 mg/kg/day.  The primary endpoint was the proportion of trimesters spent in corticosteroid-free and anti-tumor necrosis factor (TNF)-free remission.

Results:

  • 67% of azathioprine group achieved the primary endpoint compared with 56% in the conventional group.  The difference in achieving the primary endpoint was not statistically significant between the two groups.  Also, 41 (61%) of the conventional group were placed on azathioprine (mean time 11 months after enrollment).
  • The azathioprine group patients were more likely to not have perianal surgery (96%) compared with the conventional group patients (82%).
  • Adverse events included pancreatitis in 7 (10%) of azathioprine group compared with 1 (1%) of conventional group.  Elevated liver function tests were noted in 3 (4%) compared with 1 (1%) respectively.  No cases of neutropenia were noted in early azathioprine group.

The latter finding is interesting especially as the authors did not check thiopurine methyltransferase (TPMT) assays in a systematic manner.

Panes et al (for the AZTEC study group) performed a prospective double-blind trial of adult patients with a recent CD diagnosis (<8 weeks).  This study enrolled 131 patients from 31 centers in Spain.  68 received azathioprine (2.5 mg/kg/day) and 63 received placebo.

Results:

  • After 76 weeks of treatment, 30 (44.1%) azathioprine patients and 23 (36.5%) placebo-treated patients were in sustained corticosteroid-free remission (P= .48).
  • Relapse rates were lower in azathioprine group compared with placebo: 11.8% vs 30.2%.
  • Serious adverse effects were more frequent in the azathioprine group compared with placebo: 20.6% vs. 11.1% (P= .16).  In the azathioprine group, 7 (10%) developed pancreatitis, 16 (24%) developed leukopenia, 9 (13%) developed anemia, and 9 (13%) developed abnormal liver function tests.  Infections were more common in the placebo-treated group (24%) compared with 12% in the azathioprine group

The accompanying editorial should be mandatory reading for all health care providers who help manage inflammatory bowel disease (IBD) patients.  The editorial traces how thiopurines (azathioprine and 6-mercaptopurine) became an accepted cornerstone of IBD treatment.  In adults, after initial disappointing results from Summers et al (Gastroenterol 1979; 77: 847-69), efficacy was demonstrated in a seminal study by Present et al (NEJM 1980; 302: 981-87).  However, the authors note that a recent Cochrane review reported that “thiopurines are not effective for induction of remission, but are effective for maintenance of remission.”

The editorial notes that a high degree of efficacy was demonstrated from a small but influential pediatric study of 55 patients.  After a high remission rate (89%) for all patients, this study showed that among those in remission, “1 patient (4%) in the 6MP group had a relapse within 180 days of achieving remission, compared with 7 patients (28%) in the placebo group.”

The editorial draws the following conclusions from the current studies:

  • “The remaining indications for primary therapy with thiopurines are maintenance of steroid-induced remission/steroid sparing in patients with CD that is not newly diagnosed, and prevention of postoperative recurrence.”
  • “The strongest indication for thiopurines may be as part of combination therapy.”
  • “If TNF antagonists had a similar low cost as generic thiopurines, there would likely be little debate regarding an evolution toward treatment of CD with TNF antagonists, either as monotherapy or ideally as combination therapy.  Currently, the annual costs of TNF antagonists is 10-20 times that of thiopurines.”
  • Because of the difference in cost.., “the use of thiopurines in CD is likely to persist, despite the shrinking number of indications, the modest effect size, and the suboptimal safety profile.”

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