Long-term thalidomide use in refractory cutaneous lesions of systemic lupus erythematosus

Thalidomide and Lenalidomide for Refractory Systemic/Cutaneous Lupus Erythematosus Treatment: A Narrative Review of Literature for Clinical Practice

BACKGROUND

Thalidomide has shown exceptional results in systemic/cutaneous lupus erythematosus(SLE/CLE). Recently, lenalidomide has been also prescribed for SLE/CLE treatment. Literature regarding efficacy/adverse events for these drugs is scarce with a single systematic review and meta-analysis focused solely on thalidomide for refractory cutaneous lupus subtypes.

OBJECTIVE

We, therefore, addressed in this narrative review the efficacy/adverse effects of thalidomide and lenalidomide for SLE and CLE. In addition, we provide a specialist approach for clinical practice based on the available evidence.

RESULTS

Efficacy of thalidomide for refractory cutaneous lupus treatment was demonstrated by several studies, mostly retrospective with small sample size(≤20). The frequency of peripheral polyneuropathy is controversial varying from 15-80% with no consistent data regarding cumulative dose and length of use. Drug withdrawn results in clinical partial/complete reversibility for most cases (70%). For lenalidomide, seven studies (small sample sizes) reported its efficacy for SLE/CLE with complete/partial response in all patients with a mean time to response of 3 months. Flare rate varied from 25-75% occurring 0.5-10 months after drug withdrawn. There were no reports of polyneuropathy/worsening of previous thalidomide-induced neuropathy, but most of them did not perform nerve conduction studies. Teratogenicity risk exist for both drugs and strict precautions are required.

CONCLUSIONS

Thalidomide is very efficacious as an induction therapy for patients with severe/refractory cutaneous lupus with high risk of scarring, but its longstanding use should be avoided due to neurotoxicity. Lenalidomide is a promising drug for skin lupus treatment, particularly regarding the apparent lower frequency of nerve side effects.

Efficacy of Thalidomide in Discoid Lupus Erythematosus: Insights into the Molecular Mechanisms

BACKGROUND

Thalidomide has been used successfully in a variety of chronic refractory inflammatory dermatological conditions with underlying autoimmune or infectious pathogenesis. It was first used for refractory discoid lupus erythematosus (DLE) in 1983 and has steadily grown since then.

METHOD

In this review, we describe the therapeutic benefits of thalidomide for DLE treatment and its biological properties. We explain how new discoveries in DLE pathogenesis are relevant to understand thalidomide's mechanism of action and the need to find an alternative safe drug with similar therapeutic effects.

SUMMARY

Thalidomide's efficacy in DLE patients is significant, with 80-90% reaching clinical remission according to different studies. However, thalidomide's use is still limited by serious adverse effects such as teratogenicity, neurotoxicity, and thrombosis. In addition, there is a frequent rate of relapse and many patients require a long-term low dose of thalidomide as maintenance. The achievement of clinical response within weeks is key to avoid irreversible DLE fibrotic sequelae, making it critical to introduce thalidomide earlier in the DLE treatment algorithm. Recently, microarray and miRNA screenings demonstrated a significant CD4+ T enrichment and T-helper 1 response predom-inance with a dysregulation of regulatory T cell (Treg) expression in DLE lesions that induced high levels of proinflammatory, chemotaxis, and apoptotic proteins that induce the chronic inflammation response. Thalidomide's anti-inflammatory, antiangiogenic, and T-cell co-stimulatory effects may be beneficial for DLE since it promotes cytokine inhibition, inhibits macrophage activation, regulates Treg responses, inhibits angiogenesis, modulates T cells, and promotes NK cell-mediated cytotoxicity.

Thalidomide in dermatology: revisited

The use of thalidomide in relation to dermatology is well- known and enough data is available in the literature about various aspects of thalidomide. Despite being an interesting and useful drug for many dermatoses, it is associated with many health hazards including the birth defects, phocomelia. We hereby present a comprehensive review about thalidomide and its application in dermatology.

Thalidomide: Still an important second-line treatment in refractory cutaneous lupus erythematosus?

BACKGROUND

Cutaneous lupus erythematosus (CLE) can be a severe disease, characterized by extensive, disfiguring lesions and a relapsing course. Thalidomide is known as an effective treatment for CLE, however, its use is restricted by its potential side-effects. Nevertheless, it remains a valuable option to consider. Therefore, it is important to report new clinical experiences.

METHODS

The data of 30 patients with refractory CLE, who were treated with thalidomide, were retrospectively analyzed. The response rate was categorized as complete, partial or no response. The relapse rate and the occurrence of side-effects were registered.

RESULTS

Six patients prematurely discontinued treatment because of side-effects. The response rate was 100% in the remaining 24 patients, including 20 patients (83%) with complete response and 4 (27%) with partial response. Clinical relapse was frequent (73%) and occurred between 3 and 24 weeks after withdrawal of thalidomide. Nine patients (30%) developed peripheral neuropathy. In the majority, there was no complete resolution of the neuropathy-associated symptoms after stopping thalidomide. One patient developed a thrombosis in an artery stent.

CONCLUSION

Because of high risk of polyneuropathy, low-dose thalidomide should be used and long-term therapy should be avoided. Therefore, it should be recommended to combine thalidomide with other treatments for CLE.

Efficacy and safety of lenalidomide for refractory cutaneous lupus erythematosus

Introduction

Cutaneous lupus erythematosus (CLE) is a chronic disease characterized by disfigurement and a relapsing course. Thalidomide has proven its efficacy in refractory cutaneous lupus disease, although it is not exempt from significant side effects and frequent relapses after withdrawal. New thalidomide analogues have been developed but lack clinical experience. The aim of this preliminary phase II study was to evaluate the efficacy and safety of lenalidomide in patients with refractory CLE.

Methods

Fifteen patients with refractory cutaneous lupus disease were enrolled in this single-center, open-label, non-comparative pilot trial between January 2009 and December 2010. Oral lenalidomide (5 to 10 mg/day) was administered and tapered according to clinical response. Patients were followed up for a mean of 15 months (range: 7 to 30). Primary efficacy endpoint was the proportion of patients achieving complete response, defined by a Cutaneous Lupus Erythematosus Disease Area and Severity index (CLASI) activity score of 0. Other secondary endpoints included development of side effects, evaluation of cutaneous and systemic flares, and impact on the immunological parameters.

Results

One patient discontinued treatment due to side effects. All remaining patients saw clinical improvement and this was already noticeable after 2 weeks of treatment. Twelve of those patients (86%) achieved complete response but clinical relapse was frequent (75%), usually occurring 2 to 8 weeks after lenalidomide's withdrawal. No influence on systemic disease, immunological parameters or CLASI damage score was observed. Side effects including insomnia, grade 2 neutropenia and gastrointestinal symptoms, were minor (13%). These resolved after withdrawing medication. Neither polyneuropathy nor thrombosis was observed.

Conclusion

Lenalidomide appears to be efficacious and safe in patients with refractory CLE, but clinical relapse is frequent after its withdrawal.

Trial registration

ClinicalTrials.gov: NCT01408199.

Thalidomide in the treatment of refractory cutaneous lupus erythematosus: prognostic factors of clinical outcome

BACKGROUND

Although thalidomide has been shown to be effective in patients with refractory cutaneous lupus erythematosus (CLE), its use is still hampered by its potential severe side-effects and the current restricted availability.

OBJECTIVES

To evaluate prospectively the clinical efficacy and safety of low-dose thalidomide in an observational study and to establish prognostic factors of clinical outcome.

METHODS

Sixty consecutive patients with refractory CLE were treated with thalidomide (100 mg daily). Clinical response was assessed by the CLE Disease Area and Severity Index (CLASI). Clinical and immunological parameters were evaluated during treatment.

RESULTS

Patients were followed for up to 8 years (range 2-18). One patient discontinued treatment because of side-effects. Of the 59 remaining patients, 58 (98%) achieved clinical response, already noticeable at 2 weeks following treatment. Complete response occurred in 50 patients (85%). Clinical relapse was frequent (70%) and usually occurred 5 months after withdrawal or reduction of thalidomide. Subacute CLE (SCLE) was the predicting factor of long-term remission after therapy discontinuation [odds ratio (OR) 30, 95% confidence interval (CI) 5·82-154·63], whereas discoid lupus erythematosus (DLE) was predictive of relapse (OR 5·71, 95% CI 1·36-24·06). Eleven patients (18%) reported paraesthesia; in five of the 11, nerve conduction studies confirmed a sensory polyneuropathy. Neurological symptoms resolved in 12 months (range 6-18) after thalidomide withdrawal. Two patients, heavy smokers and without antiphospholipid antibodies, had a cerebral ischaemic event.

CONCLUSIONS

Low-dose thalidomide is an effective treatment for refractory CLE, but its benefits need to be balanced against the potential adverse effects. Whereas DLE forms tended to relapse and required a long-term maintenance dose of thalidomide, SCLE forms showed a sustained remission after withdrawal.

Long-term thalidomide use in refractory cutaneous lesions of lupus erythematosus: a 65 series of Brazilian patients

Thalidomide has been reported as efficacious in refractory cutaneous lupus erythematosus (LE). The most fearful side-effects are teratogenicity and neuropathy. We reported clinical efficacy of long-term low-dose use of thalidomide in 65 patients with LE, emphasizing the prevalence of adverse effects, especially of neuropathy and its related factors. Data obtained from medical records included age, sex, disease duration, and the presence of diagnostic criteria for systemic lupus erythematosus (SLE), the extent and activity of cutaneous lesions and previous treatments. Sixty-three patients (98.9%) presented complete or partial improvement with thalidomide therapy. Drowsiness occurred in 50 patients (77%). Twenty-eight patients (43.2%) presented neuropathy symptoms. Nerve conduction studies were done in 21 (75%) of them and were abnormal in 12 (57%). With the interruption of thalidomide, 24 (82.5%) had complete or partial improvement of neuropathy symptoms and 23 (82%) of them had cutaneous relapse. There were no significant differences between those who developed or not neuropathy in treatment duration, age, total dose and systemic versus cutaneous LE. In conclusion, thalidomide can be used in refractory cutaneous LE with great efficacy and relative security. Controlled studies with schemes with lower doses or intermittent usage or alternative drugs are wanted to reduce the burden of cutaneous morbidity of lupus erythematosus.

Lupus érythémateux chronique : traitement par thalidomide

INTRODUCTION

Thalidomide is the second line treatment of chronic lupus erythematosus. The efficacy of this treatment, the minimal effective doses and tolerance are poorly documented in the literature.

PATIENTS AND METHODS

We present the data of a single-center retrospective studied among 18 patients with chronic lupus erythematosus, treated with thalidomide from 1998 to 2003. Inclusion criteria were: the presence of clinical lesions evoking the disease, confirmed by histological examination and direct immunofluorescence and treatment with thalidomide for more than 2 months.

RESULTS

Mean age on diagnosis was of 35.8 years. Thalidomide had been initiated a mean of 10.6 years after diagnosis of chronic lupus erythematosus. In 13 out of 18 patients, thalidomide had been prescribed because of failure with prior treatments. Fifteen patients were improved by thalidomide (83.3 p. 100), with 11 (61 p. 100) complete and 4 (22 p. 100) partial remissions. Two (11 p. 100) patients were stabilized and treatment failed in one. The mean initial dose was of 100 mg/d (50-150), and maintenance dose was of around 50 mg/d (56 mg/d). The mean follow-up with thalidomide was of 19.4 months. Only one withdrawal due to side effects was reported. The most frequent side effects were: asthenia (33 p. 100), paresthesia (22 p. 100) and weight gain (16.6 p. 100). No side effects were reported in 10 out of 18 patients.

DISCUSSION

This study confirms the efficacy of low dose thalidomide in the treatment of chronic lupus erythematosus. In our experience, tolerance to this treatment is good, the most frequent side effect was asthenia, but usually mild. No significant peripheral neuropathy was noted. The fear of side effects, notably neurological, should not delay initiation of thalidomide in the case of failure with current treatments.

Thalidomide: dermatological indications, mechanisms of action and side-effects

Thalidomide was first introduced in the 1950s as a sedative but was quickly removed from the market after it was linked to cases of severe birth defects. However, it has since made a remarkable comeback for the U.S. Food and Drug Administration-approved use in the treatment of erythema nodosum leprosum. Further, it has shown its effectiveness in unresponsive dermatological conditions such as actinic prurigo, adult Langerhans cell histiocytosis, aphthous stomatitis, Behçet's syndrome, graft-versus-host disease, cutaneous sarcoidosis, erythema multiforme, Jessner-Kanof lymphocytic infiltration of the skin, Kaposi sarcoma, lichen planus, lupus erythematosus, melanoma, prurigo nodularis, pyoderma gangrenosum and uraemic pruritus. This article reviews the history, pharmacology, mechanism of action, clinical uses and adverse effects of thalidomide.

Thalidomide for the treatment of resistant cutaneous lupus: efficacy and safety of different therapeutic regimens

PURPOSE

Thalidomide is effective for the treatment of severe cutaneous lupus. Our aim was to study the safety and efficacy of different doses of thalidomide in this condition.

METHODS

We studied patients with severe cutaneous lupus that was unresponsive to antimalarials, prednisolone, methotrexate, azathioprine, and cyclosporin A. Starting doses of 100 mg daily (n = 16 patients), 50 mg daily (n = 17), or 50 mg on alternate days (n = 15) were compared. The response to thalidomide was categorized as complete remission, partial remission, or no visible improvement. All patients received a baseline electromyogram (EMG) followed by repeat EMG every 3 to 6 months, or sooner if neuropathic symptoms developed.

RESULTS

Forty-eight patients (46 female; mean [+/- SD] age, 44 +/- 12 years; range, 22 to 71 years) with discoid lupus (n = 18), subacute cutaneous lupus (n = 6), or systemic lupus erythematosus with skin involvement (n = 24) were included. The response rate was 81%, including 29 patients (60%) in complete remission and 10 (21%) in partial remission. Nine patients (19%) failed to respond. Thirteen patients (27%) developed peripheral neuropathy, which was EMG-proven in 11, including 4 patients in the 50-mg alternate-day group. Other side effects included drowsiness, constipation or abdominal pain, and amenorrhea. The relapse rate after stopping thalidomide was 67% (26/39). There was no association between a positive response to the drug and either starting doses or cumulative dose. Similarly, no association was found between peripheral neuropathy and the starting or cumulative dose.

CONCLUSION

Thalidomide is effective for the treatment of severe cutaneous lupus. There were no clear dose-dependent effects. However, the high incidence of neurotoxicity, even at low doses, suggests that it may be most useful as a remission-inducing drug.

Adjunctive thalidomide therapy for childhood tuberculous meningitis: results of a randomized study

Childhood tuberculous meningitis is associated with serious long-term sequelae, including mental retardation, behavior disturbances, and motor handicap. Brain damage in tuberculous meningitis results from a cytokine-mediated inflammatory response, which causes vasculitis and obstructive hydrocephalus. Thalidomide, a potent tumor necrosis factor alpha inhibitor, was well tolerated and possibly showed some clinical benefit in children with tuberculous meningitis during a pilot study. The purpose of the present study was to assess the effect of adjunctive thalidomide in addition to standard antituberculosis and corticosteroid therapy on the outcome of tuberculous meningitis. Thalidomide (24 mg/kg/day orally) or placebo was administered in a double-blind randomized fashion for 1 month to patients with stage 2 or 3 tuberculous meningitis. The study was terminated early because all adverse events and deaths occurred in one arm of the study (thalidomide group). Thirty of the 47 children enrolled received adjunctive thalidomide, of whom 6 (20%) developed a skin rash, 8 (26%) hepatitis, and 2 (6%) neutropenia or thrombocytopenia. Four deaths (13%) occurred in patients with very severe neurologic compromise at baseline; two deaths were associated with a rash. Motor outcome after 6 months of antituberculosis therapy was similar in the two groups, even though the thalidomide group showed greater neurologic compromise on admission. In addition, the mean IQ of the two treatment groups did not differ significantly (mean IQ thalidomide group 57.8 versus mean IQ control group 67.5; P = .16). These results do not support the use of adjunctive high-dose thalidomide therapy in the treatment of tuberculous meningitis.

Rasmussen syndrome and long-term response to thalidomide

We report a 13-year-old female who experienced symptoms and signs of Rasmussen encephalitis for the first time at the age of 5 years. Various therapeutic procedures, including conventional and new antiepileptic drugs, steroids, immunoglobulin, plasma exchanges, and partial hemispherectomy, were applied, but their results were unsatisfactory. During one of the exacerbations, when the patient's life was endangered, thalidomide was administered. Frequency and intensity of epileptic seizures were reduced significantly, and the quality of her life improved. Except for moderate neutropenia, the other adverse effects were not recognized. In our opinion, thalidomide is not a first-choice drug for Rasmussen encephalitis but is a good alternative only for cases refractory to other well-known and accepted therapeutic procedures.

Low-dose thalidomide therapy for refractory cutaneous lesions of lupus erythematosus

BACKGROUND

Thalidomide is an anti-inflammatory agent and an immunomodulator that inhibits the production of tumor necrosis factor alpha. It has shown promise as a treatment option for the cutaneous manifestations of lupus erythematosus (LE).

OBJECTIVE

To assess the degree of clinical response per subtype of cutaneous lupus, the duration of therapy before documented clinical improvement, and the incidence of adverse effects, including peripheral neuropathy, with low-dose thalidomide therapy at 100 mg daily in the treatment of refractory cutaneous lesions of LE.

METHODS

This retrospective medical record review of patients with refractory cutaneous manifestations of LE is one of the largest modern series in the literature. There were 29 patients seen at the Department of Dermatology, Wake Forest University School of Medicine (Winston-Salem, NC), who were unresponsive to conventional agents including antimalarial agents, and who started treatment between 1998 and 2000. Twenty-three patients who took the drug for 1 month or more were included in the analysis. Clinical responses were assessed by the investigators based on statements of improvement listed in the clinic notes and were categorized as "no response," "partial response," and "complete response." Partial response was classified as either 75% or greater or less than 75% improvement. The incidence of adverse effects including peripheral neuropathy was determined.

RESULTS

Of the 23 patients, 17 (74%) demonstrated complete resolution of the cutaneous manifestations of LE, whereas 3 patients (13%) demonstrated 75% or greater partial improvement; 3 patients (13%) had less than 75% partial clinical improvement; and 21 patients (91%) who demonstrated a complete or partial response did so within 8 weeks of initiating thalidomide therapy.

CONCLUSIONS

Based on the results of this case series, we believe that thalidomide should be given prime consideration as a treatment for antimalarial drug-resistant interface lesions of LE. The design of prospective, randomized, double-blind, placebo-controlled trials for this indication is warranted.

Thalidomide in dermatology

Thalidomide is an effective agent to treat over 25 seemingly unrelated dermatological conditions that have an inflammatory or autoimmune basis. The main side-effects of teratogenesis and peripheral neuropathy limit its use. Currently, in Australia no assurance is given as to the quality, safety and efficacy of thalidomide. The use of thalidomide for toxic epidermal necrolysis can lead to an increase in mortality, and its use as a prophylactic agent for the prevention of chronic graft-versus-host disease following bone marrow transplantation has raised more speculations as to the safety of this notorious drug. A review of the therapeutic indications for thalidomide in dermatology as well as the mechanisms of action and side-effects of this drug are presented. The current suggested guidelines for its use in clinical practice in Australia are discussed.

Theoretical basis for the activity of thalidomide

The revival of thalidomide began shortly after the drug was withdrawn from the market because of its teratogenic properties. Therapeutic effects of thalidomide were found accidentally in leprosy patients with erythema nodosum leprosum (ENL). Subsequent research widened the understanding of the activity of thalidomide, and with improved methodology and the augmented background knowledge of immunology it was possible to interpret the properties of thalidomide more coherently. Effects on tumour necrosis factor-alpha (TNFalpha) release play an important role in the ability of thalidomide to affect the immune system. Alteration of synthesis and release of cytokines such as interleukin (IL)-1, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12 and interferon-gamma is involved in the complex mechanisms of thalidomide. Thalidomide targets leucocytes, endothelial cells and keratinocytes, affecting them in a different manner and at different cellular levels. Changes in the density of adhesion molecules alter leucocyte extravasation and the inflammatory response in the tissue involved. Several mechanisms for the teratogenic action of thalidomide are currently under review, but this mode of action of the drug still remains unclear and we review evidence-based hypotheses for the teratogenicity of thalidomide. Thalidomide shows significant clinical impact in several diseases such as ENL in lepromatous leprosy, chronic graft-versus-host disease, systemic lupus erythematosus, sarcoidosis, aphthous lesions in HIV infection, wasting syndrome in chronic illness, inflammatory bowel disease, multiple myeloma and some solid tumours. In 1998 the US Food and Drug Administration approved thalidomide exclusively for the treatment of ENL, and strict conditions were stipulated for its use in order to prevent teratogenic adverse effects. However, despite the promising findings of thalidomide at the molecular level, namely its anti-TNFalpha properties and its intercalation with DNA, and activity in clinical trials, there is still a great need for more intensive research.

Update on therapy--thalidomide in the treatment of lupus

Thalidomide has been shown to be an effective treatment for cutaneous forms of lupus erythematous refractory to other therapies. Thalidomide has very serious side effects, including teratogenicity and neuropathy, which limit its clinical use in lupus to such severe refractory cases. Efficacy has been confirmed in several studies, although recurrence after discontinuation of treatment is frequent. More recent experience suggests that lower doses than originally used may be effective, which may result in a reduction in side effects. Much effort has been expended in studying the mechanisms of action of thalidomide, although as yet it is unclear which of the mechanisms identified to date contribute to its efficacy in treating cutaneous forms of lupus erythematosus. Identification of patients suitable for thalidomide therapy requires a rigorous selection process. Potential side effects should be clearly explained, particularly teratogenicity as many patients are young women. Written consent and a negative pregnancy test must be obtained prior to commencement of therapy. Reliable contraceptive measures should be strictly observed by patients taking thalidomide. Close clinical and neurophysiological supervision using nerve conduction studies should be undertaken.

Treatment of systemic lupus erythematosus

The treatment of systemic lupus erythematosus (SLE) is mainly based on a number of "traditional" drugs such as corticosteroids, antimalarials, azathioprine and cyclophosphamide. However, this scenario is rapidly changing due to the introduction of new compounds. Some of these new agents have been successfully used in other diseases, while others are being specifically designed to interfere with the immune abnormalities seen in SLE. As our knowledge on the mechanisms of immune response increases, new drugs that can interfere with T and B cell interaction and activation, production of anti-dsDNA autoantibodies, immune-complexes deposition and cytokine activation have been developed and some of these are now under investigation in SLE. Although initial data regarding their safety and efficacy are encouraging, caution must be taken before these drugs are considered as the treatment of choice for specific SLE manifestations. Specifically, controlled clinical trials with sufficient number of patients are necessary. If the promising results already available are confirmed, the use of these drugs might represent the keystone in the future management of SLE and other autoimmune diseases.

Systemic lupus erythematosus

This review covers major advances in clinical issues related to systemic lupus erythematosus (SLE) published between 1995 and 2000. The classification criteria for both SLE and antiphospholipid syndrome (APS) have been updated, and up to 19 different subsets of neuropsychiatric lupus have been defined. New epidemiological data show that the incidence of new cases and the survival of patients with SLE are both increasing. Several randomised controlled trials have defined the role of cyclophosphamide, methotrexate, antimalarials, and hormonal treatment in the management of SLE. New data are available for drugs such as ciclosporin and thalidomide. Finally, several new treatments for severe refractory cases, such as mycophenolate mofetil and stem-cell transplantation, are being increasingly used. New data also refer to management of thrombosis in APS and high-risk pregnancies in women with SLE or APS.

Therapy of systemic lupus erythematosus: new agents and new evidence

Systemic lupus erythematosus (SLE) is a disease of relatively low prevalence with a wide range of clinical manifestations. Due in part to these two facts, there is little new evidence on the treatment of lupus. In fact, randomised controlled studies and prospective series are few and usually involve a small number of patients. Despite this, some therapies have shown to be beneficial within the last five years, while others emerge as possibilities in the near future. Among the former, antimalarials appear to be the treatment of choice for maintaining mild to moderate disease in remission. Methotrexate may be an alternative to other corticosteroid-sparing drugs, especially in patients with active arthritis and skin disease. Cyclosporin can be of use in proteinuric nephritis, although the incidence of hypertension with this drug is high. Thalidomide is useful for refractory skin lesions, but the efficacy of lower, less toxic doses is still to be studied. Immunoglobulins should probably be limited to selected patients with manifestations such as thrombocytopoenia. Experience is more limited with cladribine, fludarabine, tacrolimus, danazol and pentoxifylline. New therapies for severe SLE include mycophenolate mofetil, a potent immunosuppressive drug with a reasonable safety profile and immunoablative therapy with or without stem cell transplantation, in highly resistant cases or those with a poor prognosis. Other recently developed molecules, including anti-CD40L monoclonal antibodies (mAbs), are still under investigation.