[Thalidomide: the revival]

Activity of 129 single-agent drugs in 228 phase I and II clinical trials in multiple myeloma

BACKGROUND

More than 400 preclinical studies report ≥ 1 compound as cytotoxic to multiple myeloma (MM) cells; however, few of these agents became relevant in the clinic. Thus, the utility of such assays in predicting future clinical value is debatable.

PATIENTS AND METHODS

We examined the application of early-phase trial experiences to predict future clinical adoption. We identified 129 drugs explored as single agents in 228 trials involving 7421 patients between 1961 and 2013.

RESULTS

All drugs in common use in MM (melphalan, dexamethasone, prednisone, cyclophosphamide, bendamustine, thalidomide, lenalidomide, pomalidomide, bortezomib, carfilzomib, and doxorubicin) demonstrated a best reported response rate of ≥ 22%. Older agents, including teniposide, fotemustine, paclitaxel, and interferon, also appear active by this criterion; however, if mean response rates from all reported trials for an agent are considered, then only drugs with a mean response rate of 15% partial response are in clinical use.

CONCLUSION

Our analysis suggests that thresholds of 20% for best or 15% for mean response are highly predictive of future clinical success. Below these thresholds, no drug has yet reached regulatory approval or widespread use in the clinic. Thus, this benchmark provides 1 element of the framework for guiding choice of drugs for late-stage clinical testing.

[Thrombotic accidents induced by thalidomide: two cases]

INTRODUCTION

First used as a sedative, thalidomide was taken out the market because of its teratogenicity. Despite other side effects, especially neuropathies, this drug is now again prescribed in various autoimmune and neoplasic diseases. Recently, venous or arterial thrombotic events have been described after the introduction of thalidomide.

EXEGESIS

In this report, we describe two new venous thrombosis cases occurring during a treatment with thalidomide. The first case is a 37-year-old man treated for a discoid lupus, who developed three deep-vein thrombosis and a massive pulmonary embolism, with recurrent thrombosis even with an efficient anticoagulation therapy until the final stop of thalidomide. The second one is a 66-year-old woman treated with thalidomide for a multiple myeloma and a melanoma in therapeutic escape, who developed a deep-vein thrombosis two months after the beginning of her treatment. Published reports suggest that most thrombotic events appeared under three months after the introduction of the treatment and that thalidomide could have acted as a precipitating or as a starting factor in a patient population already at risk of thrombosis. Those complications should be particularly severe, but the mechanism underlying thrombosis with thalidomide is unknown.

CONCLUSION

A complete coagulation check-up is advised before beginning a treatment with thalidomide.

Current treatment strategies for multiple myeloma

Until 1990, the melphalan-prednisone regimen was the standard treatment for multiple myeloma (MM). The role of alpha-interferon still remains controversial, both in induction therapy and in maintenance therapy. Over the last 10 years, there has been considerable improvement in the treatment of MM. In patients under 65 years of age, high-dose therapy with autografting has clearly demonstrated an advantage over conventional treatment. Bisphosphonates have proved very useful in reducing skeletal events. More recently, an old drug, thalidomide, has shown surprising efficacy in patients with advanced MM. Future trends include the extension of high-dose therapy to older patients and the use of immunotherapy in induction and/or maintenance therapy.

Thalidomide: new indications?

Thalidomide, which was developed as a nonbarbiturate sedative agent, was taken off the market in 1961 after it was linked to a spate of major birth defects. Gradually, thalidomide was reintroduced for the treatment of a few skin diseases including leprous erythema nodosum, severe mucosal ulcers (e.g., associated with HIV infection or Behçet's disease), lymphocytic skin infiltrations, cutaneous lupus erythematosus, and chronic graft-versus-host disease. Recent reports of original pharmacological properties including modulation of cytokine production (mainly reduced TNF-alpha production) and inhibition of angiogenesis have led to the suggestion that thalidomide may be useful in some inflammatory and neoplastic conditions. Several open-label studies and case reports have described the effects of thalidomide in Crohn's disease, rheumatoid arthritis, ankylosing spondylarthritis, systemic sclerosis, and a few other systemic disorders. In these indications, minor but dose-limiting side effects were apparently common. Thalidomide analogs with better acceptability profiles are under evaluation. The anti-angiogenic effects of thalidomide may make this compound valuable as single-drug therapy or as an adjunct to chemotherapy in patients with cancer, particularly those with metastases or multiple myeloma. This possibility requires further evaluation.