Treatment of pediatric refractory Crohn’s disease with thalidomide

Long-term outcomes of thalidomide in pediatric Crohn's disease

BACKGROUND AND AIM

In this largest pediatric cohort to date in Asian population, we aimed to report our long-term real-life experience with thalidomide treatment in pediatric Crohn's disease (CD).

METHODS

A retrospective single-center analysis of pediatric CD patients treated by thalidomide was conducted. The clinical characteristics and outcomes were extracted. Primary outcomes were clinical response and remission rate at different time points, especially comparing the difference between monogenic and non-monogenic mutation patients. We also evaluated the long-term safety of thalidomide.

RESULTS

A total of 62 patients met the inclusion criteria. The median follow-up period was 30.5 months. Among all, 19 patients (30.6%) were diagnosed with monogenic mutation during treatment. Clinical remission rate was 53.2% (33/62) at 6 months, 54.8% (34/62) at 12 months, and 33.9% (21/62) at the end of follow-up. Clinical remission rates between non-monogenic and monogenic groups at the end were statistically different (44.2% [19/43] vs 10.5% [2/19], P < 0.05). At 12 months, 66.7% (30/45) were with normalized C-reactive protein level. Most patients (95.4%, 21/22) discontinued steroids with a median time of 4.4 months. Twelve patients relapsed, but no risk factor was identified to be significantly associated with relapse. A total of 45.2% (28/62) patients experienced an adverse event, in which 22 patients stopped thalidomide due to safety concern. Cumulative dose was not associated with abnormal electromyography but with the occurrence of adverse events.

CONCLUSIONS

Thalidomide was clinically efficacious and safe among pediatric CD. Our results suggest that it is an alternative therapy in monogenic mutation patients.

Phenotypic Characterization of Very Early-Onset Inflammatory Bowel Disease with Interleukin-10 Signaling Deficiency: Based on a Large Cohort Study

BACKGROUND

Interleukin-10 (IL10)/interleukin-10 receptor (IL10R) deficiency is a rare disease with life-threatening infantile-onset colitis. We sought to accurately phenotype this disorder based on a large cohort of patients with a proven defect of IL10 signaling and to clarify the effects of allogeneic hematopoietic stem cell transplantation (HSCT).

METHODS

We analyzed the phenotypes of our 61 patients and reviewed 78 other previously reported cases with identified mutations in the genes encoding IL10 or IL10R. We also compared the clinical features of patients with interleukin-10 receptor B (IL10RB), interleukin-10 receptor A (IL10RA), and IL10 mutations. The therapeutic effects of allogeneic HSCT were evaluated.

RESULTS

We found that the disease onset time was extremely early: 70.3% within 30 days postnatal and 94.9% within the first 6 months of life. In addition, 94.2% of patients typically presented with perianal lesions. Oral ulcers and skin rash were common extra-intestinal manifestations (33.8% and 51.8%, respectively). There was no statistically significant difference in disease onset time, perianal lesion involvement, or mortality rate among patients with IL10RB, IL10RA, or IL10 deficiency. However, the surgery rate was higher in patients with IL10RB mutations than in those with IL10 or IL10RA mutations (P < 0.05). Compared with those with IL10RA deficiency, a higher percentage (32%, 9 of 28) of patients with IL10RB mutations developed B-cell lymphoma (P < 0.01). Compared with other regions, a higher percentage (98.7%) of IL10RA mutations was detected among patients in East Asia countries (P < 0.01), with hot-spot mutation sites of c.C301T and c.G537A. Allogeneic HSCT is efficacious but has a high mortality rate (17.5%, 7 of 40).

CONCLUSIONS

Our study expands the current knowledge on the genotype-correlated phenotypes with a defect of IL10 signaling. B-cell lymphoma was more frequent than would be expected in patients with IL10RB mutations. There may be a unique genetic architecture among Eastern Asia compared with other populations. Although allogeneic HSCT represents a causal therapeutic approach for IL10-and IL10R-deficient patients, a word of caution is warranted.

Umbilical Cord Blood Transplantation Corrects Very Early-Onset Inflammatory Bowel Disease in Chinese Patients With IL10RA-Associated Immune Deficiency

BACKGROUND

Hematopoietic stem cell transplantation is considered the only curative therapy for very early-onset inflammatory bowel disease with specific immune defects, such as interleukin-10 receptor deficiency. We performed reduced-intensity conditioning before umbilical cord blood transplantation in patients with interleukin-10 receptor-A deficiency.

METHODS

We enrolled 9 very early-onset inflammatory bowel disease patients with typical manifestations. We diagnosed the patients with interleukin-10 receptor-A deficiency by whole-exome sequencing. Umbilical cord blood transplantation was performed in all 9 patients. Eight patients received the reduced-intensity conditioning regimen, and 1 patient received the myeloablative conditioning regimen.

RESULTS

All 9 patients received transplantation between the ages of 6 months to 43 months (average, 16.8 months) with body weights ranging from 3 to 10.4 kg (average, 6.6 kg). The patients displayed complete chimerism at 2-8 weeks after transplantation; 6 patients achieved complete remission without evidence of graft-vs-host disease or infections; 1 patient died of chronic lung graft-vs-host disease at 6 months post-transplantation; and the other 2 patients died of sepsis post-transplantation because of unsuccessful engraftments. Severe malnutrition and growth retardation associated with interleukin-10 receptor-A deficiency were significantly improved post-transplantation.

CONCLUSIONS

We recommend umbilical cord blood transplantation as a potential treatment for very early-onset inflammatory bowel disease with a defined monogenic immunodeficiency, and we suggest that reduced-intensity conditioning chemotherapy is more suitable than myeloablative conditioning for patients with severe malnutrition and bowel disease. We have demonstrated success with reduced-intensity conditioning for interleukin-10 receptor-A deficiency in pediatric patients with severe clinical conditions. 10.1093/ibd/izy028_video1izy028.video15786489183001.

Phenotype and Management of Infantile-onset Inflammatory Bowel Disease: Experience from a Tertiary Care Center in China

BACKGROUND

Infantile-onset inflammatory bowel disease (IBD) comprises rare and clinically severe disorders. We examined the phenotypes and genetic causes of patients with infantile-onset IBD from a tertiary medical center.

METHODS

We enrolled 38 patients with infantile-onset IBD and applied standardized treatment with medical, surgical, and supportive care. Targeted sequencing and whole-exome sequencing were performed. Clinical data were retrieved from medical records.

RESULTS

Median age of onset of disease was 12.5 (interquartile range: 7.0-30.0) days. All patients had diarrhea, whereas 18 (47.4%) patients reported hematochezia. Thirteen (34.2%) patients had oral ulcers, 15 (39.5%) patients had perianal abscess, and 9 (52.9%) female patients had rectovaginal fistula. Six (18.8%) patients had intestinal strictures and 4 (12.1%) patients had perforation. Twelve (31.6%) patients underwent surgical procedures. Median age of surgery was 272.5 days, and cumulative probability for surgery during first year was 32.1%. One-year mortality of patients was 25.9%. Sequencing showed 24 (63.2%) patients had causative IL10RA mutations, 1 patient had EPCAM mutation, 1 patient had TNFAIP3 mutation, and 1 patient had LRBA mutation, whereas causative mutations cannot be identified in the other 11 (28.9%) patients. Umbilical cord blood stem cell transplantation has been applied to 8 cases with IL10RA mutations, of whom 5 (71.4%) patients have achieved clinical remission.

CONCLUSIONS

Patients with infantile-onset IBD had severe phenotype and early onset. Medical, surgical interventions with supportive care are essential. High-throughput sequencing ensures appropriate treatment. Hematopoietic stem cell transplantation can be performed in selected patients with IL10RA mutations (see Video Abstract, Supplemental Digital Content 1, http://links.lww.com/IBD/B657).

Efficacy of thalidomide therapy in pediatric Crohn’s disease with evidence of tuberculosis

AIM

To evaluate the efficacy of thalidomide for treating troublesome cases of pediatric Crohn’s disease (CD) with tuberculosis infection.

METHODS

A retrospective study of clinical outcome among children treated with thalidomide was conducted. All patients had evidence of tuberculosis infection with a failure of anti-tuberculosis treatment for more than one year, and were subsequently diagnosed with CD. All the patients received thalidomide treatment with a starting dose of 1.2-2.5 mg/kg per day. Remission was defined as pediatric CD activity index less than or equal to 10.

RESULTS

Ten patients with CD were treated with thalidomide at an average age of 7.2 years and followed up for a median of 22.2 mo. Clinical remission rate was 60% after 9-12 mo of thalidomide treatment. One patient with no response had an interleukin-10 receptor alpha gene mutation. Erythrocyte sedimentation rate, C-reactive protein and platelet count showed a dramatic decrease; hemoglobin level and weight improved significantly after thalidomide treatment when compared with the baseline values.

CONCLUSION

Thalidomide is an effective and safe drug for remission of CD in pediatric patients who have been treated for tuberculosis.

Endoscopic and Histologic Healing in Children With Inflammatory Bowel Diseases Treated With Thalidomide

BACKGROUND & AIMS

Mucosal healing, determined by endoscopic evaluation, is one of the most important prognostic markers for patients with inflammatory bowel diseases. Findings from histologic evaluation, however, could complement findings from endoscopy in assessing mucosal responses to treatment. We analyzed long-term results of children treated with thalidomide to determine the association between clinical response and histology and endoscopy findings.

METHODS

We collected data from 2 multicenter trials of 70 children with refractory Crohn's disease (CD) or ulcerative colitis (UC) (2-18 years old; ileocolonic or colonic disease) given thalidomide or placebo (NCT00720538). Clinical remission and clinical response at 8 weeks were defined as a pediatric CD activity index scores 10 points or lower and a decrease of at least 50% from baseline, respectively, for patients with CD; and as a pediatric UC activity index score below 10 and a decrease of at least 20 points from baseline, respectively, for patients with UC. Patients with a clinical response to 8 weeks' treatment with thalidomide underwent endoscopic examination with biopsy collection at study weeks 12 and 52. Severity of inflammation in patients with UC was assessed by Mayo score and in patients with CD by 4-grade system. Biopsies were assessed for signs of active inflammation, erosion or ulceration, and crypt abscesses and assigned a histologic score.

RESULTS

Clinical remission was observed in 42 patients (60.0%) and clinical response in 45 patients (64.2%) at Week 8. At Week 52, a total of 38 patients (54.3%) were still in clinical remission or still had a clinical response; 29 patients (41.4%) had mucosal healing, defined as complete healing of erosions or ulcerations, and 20 patients (27.7%) had histologic healing, defined as complete absence of markers of inflammation. Of patients with clinical remission or clinical response, 75.3% also had mucosal healing and 52.6% also had histologic healing. The probability of achieving mucosal healing decreased significantly with increasing values of erythrocyte sedimentation rate (adjusted odds ratio, 0.96; 95% CI, 0.93-0.98; P = .006).

CONCLUSIONS

In a long-term analysis of data from 2 clinical trials of pediatric patients with CD or UC, 52 weeks' treatment with thalidomide led to clinical remission in 54.3% of patients with ileocolonic or colonic disease; of these patients, 75.3% had mucosal healing and 52.6% also had histologic healing. Further studies are needed to determine how thalidomide therapy affects long-term progression of inflammatory bowel diseases. (ClinicalTrials.gov number NCT00720538).

Thalidomide is a therapeutic agent that is effective in inducing and maintaining endoscopic remission in adult CD patients

BACKGROUND AND AIMS

Previous studies have indicated that thalidomide may be effective in achieving clinical remission and response; however, there is a lack of studies on its effect in endoscopic remission. The aim of this study was to assess the efficacy and safety of thalidomide in inducing and maintaining endoscopic remission.

METHODS

A retrospective study was conducted in adult Crohn's disease (CD) patients treated with thalidomide. Patients were assessed based on their medical records. Endoscopy was performed after 4-6 months of thalidomide administration, and the simple endoscopic score for CD (SES-CD) was obtained.

RESULTS

Twenty of the 21 (95.2%) eligible patients were recruited. Endoscopic remission was achieved in 7 of the 14 (50%) endoscopy active patients who received thalidomide treatment, whereas 10 (71.4%) patients showed an endoscopy response. The other 6 patients in endoscopic remission still maintained remission after thalidomide treatment. The SES-CD in endoscopy active patients was significantly reduced after thalidomide treatment (P<0.05). A total of 32 adverse events occurred in 17 of the 21 (81.0%) patients. Adverse events resolved spontaneously in 11 (64.7%) patients and resulted in treatment discontinuation and dose reduction in 4 (19.1%) and 2 (9.5%) patients, respectively.

CONCLUSIONS

Thalidomide therapy is effective in inducing and maintaining endoscopic remission in adult CD patients. However, side effects may limit its clinical use in CD treatment.

Inflammatory bowel disease in Chinese children: A retrospective analysis of 49 cases

To present study reports the clinical characteristics, diagnosis and management of pediatric patients with inflammatory bowel disease (IBD) in China. Clinical records of 49 pediatric patients with IBD at Fudan University Children's Hospital (Shanghai, China) between July 2001 and May 2012 were reviewed. Of 49 patients (30 males and 19 females), 8 patients had ulcerative colitis (UC) and 41 patients had Crohn's disease (CD). The mean age was 10.4 years in patients with UC and 10.1 years in patients with CD. The percentages of patients with UC with abdominal pain, diarrhea or rectal bleeding were 62.5, 100 and 87.5%, respectively, and that of CD patients were 75.6, 61 and 39%, respectively. Patients with UC were underweight (37.5%), and had oral ulcers (12.5%) and arthritis (12.5%), and patients with CD were underweight (34.1%), and had oral ulcers (26.8%), anal fistulas (22%) and arthritis (19.5%). Patients with CD had a higher proportion of immunoglobulin G, C-reactive protein and erythrocyte sedimentation rate compared with patients with UC. Histologic lesions of patients with UC were primarily located in the sigmoid colon (75%), transverse colon (50%) or pan-colon (50%), and in patients with CD they were located in the distal ileum (51.2%), ileocecum (58.5%) or upper gastrointestinal tract (41.5%). All patients underwent colonoscopies and 13 underwent double-balloon enteroscopies. Standard treatment for IBD, including corticosteroids, 5-aminosalicylate, and immunosuppressants (6-mercaptopurine and azathioprine), were administered to all patients. In addition 3 patients were treated with infliximab and 10 patients were treated with thalidomide. Comprehensive assessment of clinical, laboratory, endoscopic, and pathohistological data will benefit the timely diagnosis of IBD.

Thalidomide induces mucosal healing in postoperative Crohn disease endoscopic recurrence: Case report and literature review

BACKGROUND

Thalidomide has been successful use in patients with refractory Crohn disease (CD) in recent years.

METHODS

We collected the data of a postoperative CD patient who was prescribed thalidomide to induce remission and reviewed the relevant literatures.

RESULTS

A 51-year-old female was diagnosed as CD after an urgent terminal intestinal resection and presented endoscopic recurrence despite the prophylactic treatment with azathioprine (AZA). Fortunately, she achieved mucosal healing (MH) at a low dose of thalidomide for 15 months.

CONCLUSION

Thalidomide is effective to induce MH in the postoperative CD endoscopic recurrence.

Thalidomide for inflammatory bowel disease: Systematic review

BACKGROUND

Thalidomide is an immunomodulatory drug used in the experimental treatment of refractory Crohn disease and ulcerative colitis. We aimed to review the existing evidence on the efficacy and safety of thalidomide in the treatment of inflammatory bowel diseases.

METHODS

CENTRAL, MEDLINE, LILACS, POPLINE, CINHAL, and Web of Science were searched in March 2016. Manual search included conference and reference lists. All types of studies, except single case reports, were included. Outcomes evaluated were: induction of remission; maintenance of remission; steroid reduction; effect on penetrating Crohn disease; endoscopic remission; adverse events.

RESULTS

The research strategies retrieved 722 papers. Two randomized controlled trials and 29 uncontrolled studies for a total of 489 patients matched the inclusion criteria. Thalidomide induced a clinical response in 296/427 (69.3%) patients. Clinical remission was achieved in 220/427 (51.5%) cases. Maintenance of remission was reported in 128/160 (80.0%) patients at 6 months and in 96/133 (72.2%) at 12 months. Reduction in steroid dosage was reported in 109/152 (71.7%) patients. Fistulas improved in 49/81 (60.5%) cases and closed in 28/81 (34.6%). Endoscopic improvement was observed in 46/66 (69.7%) and complete mucosal healing in 35/66 (53.0%) patients. Cumulative incidence of total adverse events and of those leading to drug suspension was 75.6 and 19.7/1000 patient-months, respectively. Neurological disturbances accounted for 341/530 (64.3%) adverse events and were the most frequent cause of drug withdrawal.

CONCLUSION

Existing evidence suggests that thalidomide may be a valid treatment option for patients with inflammatory bowel diseases refractory to other first- and second-line treatments.

Thalidomide pharmacokinetics in sheep

AIM

To determine the half life (T1/2), time taken to reach maximum plasma concentration (Tmax) and maximum plasma concentration (Cmax) of thalidomide in sheep following I/V, oral and topical treatment with a single dose of thalidomide.

METHOD

Three groups of 4-6-month-old ram lambs were treated with thalidomide dissolved in dimethylsulphoxide (DMSO). The first group (n=10) was treated I/V with 100 mg thalidomide in 2 mL DMSO; the second group (n=8) received 400 mg thalidomide in 2 mL DMSO orally, and the third group (n=8) had 400 mg thalidomide in 4 mL DMSO applied topically. Plasma samples were collected up to 36 hours after treatment, snap-frozen at -80°C and analysed for concentrations of thalidomide using high performance liquid chromatography.

RESULTS

Following I/V administration, T1/2 was 5.0 (SEM 0.4) hours, volume of distribution was 3,372.0 (SEM 244.3) mL/kg and clearance was 487.1 (SEM 46.1) mL/hour.kg. Topical application of 400 mg thalidomide did not increase plasma concentrations. Following oral administration, thalidomide bioavailability was 89%, with T1/2, Tmax, and Cmax being 7.2 (SEM 0.8) hours, 3.0 (SEM 0.4) hours and 1,767.3 (SEM 178.1) ng/mL, respectively.

CONCLUSION

Topical administration using DMSO as a solvent did not increase concentrations of thalidomide in plasma. The mean pharmacokinetic parameters determined following oral treatment with 400 mg of thalidomide were similar to those reported in humans receiving a single 400 mg oral dose (T1/2 7.3 hours; Tmax 4.3 hours and Cmax 2,820 ng/mL). There is potential for thalidomide to be used as a model for the treatment of chronic inflammatory conditions in sheep, such as Johne's disease, where tumour necrosis factor alpha plays a pathogenic role.

Systematic review: thalidomide and thalidomide analogues for treatment of inflammatory bowel disease

BACKGROUND

It has been reported that thalidomide may be effective in treating inflammatory bowel disease (IBD).

AIM

To review the evidence examining the efficacy and safety of thalidomide for inducing and maintaining remission in Crohn's disease (CD) and ulcerative colitis (UC).

METHODS

The Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, PubMed (1950-August 2014), EMBASE (1984-August 2014), Scopus, and Web of knowledge were searched for randomised controlled trials (RCTs), observational studies and case series. The primary outcomes were induction of remission or response for active IBD or relapse rate for patients in remission and subsequently on thalidomide/analogues for at least 3 months.

RESULTS

Twelve studies (2 RCTs and 10 case series) met the inclusion criteria for inducing remission and included 248 patients (10 with UC, 238 with CD). Only one RCT of paediatric CD achieved high quality scores (remission rate thalidomide: 46%, placebo: 12%; p=0.01). The crude pooled remission rate for thalidomide was 49% and 25% in luminal and perianal CD respectively. For UC, 50% achieved remission and 10% had partial response. One case series reported 21 patients (17 CD, four UC) who maintained remission for 6 months. Many adverse events were reported including sedation (32%) and peripheral neuropathy (20%).

CONCLUSIONS

One high quality RCT showed that thalidomide is effective for inducing remission in paediatric CD. The current evidence is insufficient to support using thalidomide to induce remission in UC or adult CD, or to maintain remission in IBD. Significant adverse events may occur, necessitating discontinuation of thalidomide.

The clinical implications of thalidomide in inflammatory bowel diseases

Thalidomide has anti-inflammatory and anti-angiogenetic activity that makes it suitable for treating inflammatory bowel diseases (IBD). The recent guidelines from the European Crohn's and Colitis Organization/European Society for Pediatric Gastroenterology Hepatology and Nutrition conclude that thalidomide cannot be recommended in refractory pediatric Crohn's disease but that it may be considered in selected cohorts of patients who are not anti-TNFα agent responders. The main adverse effect is the potential teratogenicity that renders the long-term use of thalidomide problematic in young adults due to the strict need for contraceptive use. In short-term use it is relatively safe; the most likely adverse effect is the neuropathy, which is highly reversible in children. So far the use of thalidomide is reported in 223 adult and pediatric IBD patients (206 with Crohn's disease). In the following sections, the authors will discuss efficacy and safety of thalidomide, in the short-term treatment of IBD.

An update on medical management on Crohn's disease

INTRODUCTION

The management of Crohn's disease (CD) is continuously evolving. New issues emerging from more recent studies could influence the decision-making process in clinical practice.

AREAS COVERED

The aim of this review article is to highlight critical issues on the management of CD, new evidence from clinical trials, long-term prospective studies and real life experience, beyond the current guidelines.

EXPERT OPINION

The role of mucosal healing in clinical practice is uncertain, clinical remission remains the primary end point. The timing for the definition of steroid-resistant CD should be considered between 2 and 4 weeks. Early treatment strategy with immunomodulators is effective for inducing remission but no controlled data are available regarding long-term outcome. Combination therapy (anti-TNFs agents and immunosuppressors) is more effective than single therapy but there is a lack of long-term data and an increased risk of malignancy. The effect of mesalazine, metronidazole and azathioprine in reducing postoperative recurrence is not clinically relevant; biologics are effective, but the duration of treatment is unknown. New drugs are under investigation in order to find exit strategy for patients who no longer respond to biologics. Combination therapy set on anti-TNF-α is until now the best option both to achieve fistula healing and avoid recurrence.

Medical management of Crohn's disease

INTRODUCTION

The medical approach to Crohn's disease has been modified in recent years thanks to the introduction of new therapies, like biologics. Also, well-designed studies and systematic reviews have allowed better evaluation of the role of old drugs like steroids and immunosuppressors. This review aims to evaluate the recent evidence on the medical approach to Crohn's disease in the different settings of the disease.

AREAS COVERED

Randomized controlled trials and meta-analyses were included in the review. The research on all the studies discussed was based on the Cochrane Library, Medline and Embase, using the following medical subject headings: Crohn's disease, clinical trial, therapy, 5-aminosalicylic acid, steroid, budesonide, immunosuppressant, anti-meta-analysis TNF and biologics.

EXPERT OPINION

In a mild active inflammatory ileocecal disease, budesonide is considered the best approach. The efficacy of aminosalicylates is limited, but a trial that has recently compared aminosalicylates and budesonide has shown that the two drugs are comparable. In a mild colonic disease, sulfasalazine, antibiotics and steroids are effective but the evidence for antibiotics is less clear. The maintenance of remission in this setting is debatable, but sulfasalazine seems the better choice. In a moderate severe ileal and colonic disease, steroids are the best therapy to induce remission. Once remission is reached, immunosuppressors remain today the better choice to maintain the remission. Anti-TNF therapy is indicated in patients intolerant or not responding to steroids and immunosuppressors and in fistulizing Crohn's disease. Early therapy with biologics may be considered in patients with severe disease.

[The thalidomide experience: review of its effects 50 years later]

This year is the 50(th) anniversary of the discovery that the drug thalidomide causes birth defects and should therefore be considered as a teratogen. However, despite the existence of several other drugs that are also human teratogens, thalidomide continues to cause concern among health professionals as well as the general population. The objectives of this article are to make a short historical review of the discovery that this drug severely alters the embryo development, the critical period of gestation and the identification of the real effect of thalidomide. For the first time an analysis is provided to identify the type of malformations for which thalidomide really increases the risk. The proportions of the different types of malformations groups from the series of patients considered to be affected by thalidomide from the literature were compared with the proportions of the same malformations groups in non-exposed infants from the Spanish Collaborative Study of Congenital Malformation (ECEMC). The aim of the analysis was to calculate the relative frequencies of 13 groups of malformations observed in series of patients exposed to thalidomide, by comparison with the same groups of defects in 1,491 patients with limb malformations from the ECEMC consecutive newborn infants, non-exposed to thalidomide. The results showed that the groups with the most classical limb malformations attributed to thalidomide (phocomelia, thumb absence/hypoplasia) had a significantly very higher frequency in exposed cases than in the ECEMC's cases. However, cases presenting with only lower limb malformations were 3 times less frequent in thalidomide cases than in those of ECEMC. Finally, other groups presented the same frequency as those observed in the ECEMC's cases. The results of the 2 last groups, strongly suggests that they were not due to the effect of thalidomide. In addition to the short historical review of the teratogenicity risk of thalidomide, and their new therapeutic properties, it is documented that, as it happens with all other currently known human teratogens, not all malformations observed in infants prenatally exposed to thalidomide were caused by this drug. Finally, it is discussed the paradox that the «feared» thalidomide drug causing a great human drama affecting about 10,000 infants has led to a formidable contribution to the scientific knowledge, and large range of therapeutic applications.