CC-5013 (Celgene)

Celgene, in collaboration with the National Cancer Institute, is developing CC-5013, the lead compound in a series of thalidomide derivatives that inhibit TNFalpha overproduction, for the potential treatment of hematological and solid tumor cancers and inflammatory diseases.

Phase I study to determine the safety, tolerability and immunostimulatory activity of thalidomide analogue CC-5013 in patients with metastatic malignant melanoma and other advanced cancers

We assessed the safety, tolerability and efficacy of the immunomodulatory drug, CC-5013 (REVIMID™), in the treatment of patients with metastatic malignant melanoma and other advanced cancers. A total of 20 heavily pretreated patients received a dose-escalating regimen of oral CC-5013. Maximal tolerated dose, toxicity and clinical responses were evaluated and analysis of peripheral T-cell surface markers and serum for cytokines and proangiogenic factors were performed. CC-5013 was well tolerated. In all, 87% of adverse effects were classified as grade 1 or grade 2 according to Common Toxicity Criteria and there were no serious adverse events attributable to CC-5013 treatment. Six patients failed to complete the study, three because of disease progression, two withdrew consent and one was entered inappropriately and withdrawn from the study. The remaining 14 patients completed treatment without dose reduction, with one patient achieving partial remission. Evidence of T-cell activation was indicated by significantly increased serum levels of sIL-2 receptor, granulocyte–macrophage colony-stimulating factor, interleukin-12 (IL-12), tumour necrosis factor-α and IL-8 in nine patients from whom serum was available. However, levels of proangiogenic factors vascular endothelial growth factor and basic foetal growth factor were not consistently affected. This study demonstrates the safety, tolerability and suggests the clinical activity of CC-5013 in the treatment of refractory malignant melanoma. Furthermore, this is the first report demonstrating T-cell stimulatory activity of this class of compound in patients with advanced cancer.

The role of immunomodulatory drugs in multiple myeloma

Thalidomide has shown promise in the treatment of newly diagnosed multiple myeloma and relapsed/refractory disease, but side effects such as somnolence, constipation, and neuropathy limit its use. CC-5013, an immunomodulatory drug (IMiD), is more potent than thalidomide. CC-5013 has various immunomodulatory effects, including growth arrest or apoptosis of drug-resistant myeloma cell lines and inhibition of binding of myeloma cells to bone marrow stromal cells. Clinically, 17 of 24 patients (71%) with relapsed/refractory disease experienced a reduction of paraprotein of > or = 25% following treatment with CC-5013, including 11 who had a history of treatment with thalidomide. Another two experienced stable disease. Median time to best response was 2 months (range, 1 to 11) and median duration was 6 months (range, 2 to 18). Grade 3 thrombocytopenia was seen in 20% of patients; grade 3 neutropenia was seen in 60%; and grade 4 neutropenia was seen in 16%. CC-5013 use was not associated with somnolence, constipation, or neuropathy. This article reviews thalidomide in multiple myeloma, the effects of thalidomide analogues IMiDs, and the preclinical and clinical data on CC-5013 in relapsed/refractory multiple myeloma.

Thalidomide and CC-5013 in multiple myeloma: the University of Arkansas experience

Based on the activity of single-agent thalidomide in relapsed/refractory multiple myeloma in a landmark phase II study of 169 patients conducted at the University of Arkansas for Medical Sciences (UAMS), UAMS initiated several trials of thalidomide and the more potent thalidomide analog CC-5013. In an ongoing trial evaluating thalidomide plus the proteasome inhibitor bortezomib and dexamethasone in patients with relapsed/refractory disease following stem cell transplantation, approximately 50% of patients have experienced a paraprotein reduction of 50% or greater. In patients without cytogenetic abnormalities, the estimated 12-month event-free and overall survival rates are 69% and 100%, respectively. In a second ongoing trial building on the UAMS Total Therapy I regimen, newly diagnosed patients are randomized to thalidomide or no thalidomide pretransplantation followed by consolidation therapy with dexamethasone and multiagent chemotherapy post-transplantation (Total Therapy II). Although the Total Therapy II regimen appears to be superior to the original Total Therapy I regimen, assessment of the effect of thalidomide on Total Therapy II is pending accrual completion. Lastly, based on the increased potency and reduced toxicity profile of CC-5013 compared with thalidomide, a study of CC-5013 in patients with relapsed/refractory disease following transplantation was initiated. Patients are randomized to CC-5013 25 mg daily for 20 days versus CC-5013 50 mg every other day for 10 days. Preliminary results indicate the superiority of the 25-mg arm, with 40% of patients randomized to that arm experiencing a paraprotein reduction of 50% or greater. These preliminary results corroborate the role for thalidomide and CC-5013 in relapsed/refractory and newly diagnosed multiple myeloma based on the UAMS phase II study as well as several other studies of these agents outside of UAMS.

Immunomodulatory drug costimulates T cells via the B7-CD28 pathway

Although thalidomide (Thal) does not directly induce T-cell activation, it increases proliferation of T cells following CD3 activation. In this study, we examined the immunomodulatory effects of a more potent analog of Thal, immunomodulatory drug (IMiD), on T cells. Although IMiD3 does not directly stimulate proliferation of normal donor CD3+ T cells, it significantly costimulates proliferation of CD3+ T cells induced by CD3 ligation (stimulation index [SI], 2.4), immature dendritic cells (DCs; SI, 2.1), and mature DCs (SI, 2.6). T-cell proliferation triggered by DCs was abrogated by cytotoxic T lymphocyte antigen 4-immunoglobulin (CTLA-4-Ig), and IMiD3 partially overcomes this inhibitory effect. IMiD3 also overcomes the inhibitory effects of CTLA-4-Ig on Epstein-Barr virus (EBV) and influenza (Flu)-specific CD4 and CD8 T-cell responses, as measured by cytokine capture and enzyme-linked immunosorbent spot (ELISPOT) assay. IMiD3 did not induce up-regulation of CD28 expression on T cells, or of CD80-CD86 expression on dendritic cells. Importantly, IMiD3 triggers tyrosine phosphorylation of CD28 on T cells, followed by activation of nuclear factor kappaB (NF-kappaB), a known downstream target of CD28 signaling. These results therefore define the costimulatory mechanism whereby IMiD3 induces T-cell activation and provide the cellular and molecular basis for use of IMiD3 as an adjuvant in immunotherapeutic treatment strategies for multiple myeloma.

Novel therapies in multiple myeloma

The discovery of the activity of thalidomide in myeloma in the late 1990s transformed the therapy of myeloma dramatically. Apart from providing a useful treatment option for patients with myeloma, it has spurred clinical investigation of several other nonchemotherapeutic agents for this disease. These active, promising agents include CC-5013 (a thalidomide analog) and bortezomib (a proteasome inhibitor), as well as other agents, such as arsenic trioxide, ENMD 0995 and 2-methoxyestradiol. Preliminary data show that a number of these agents are active in treating disease that has relapsed after conventional chemotherapy as well as after high-dose therapy and transplantation, and some agents are active even after other novel agents have failed. The only novel drug that is commercially available currently is thalidomide, which has a therapeutically relevant benefit at all stages of the disease. A therapeutic trial of thalidomide is essential for all patients with myeloma. There are in vitro and in vivo data showing synergy between some of the novel agents. Although these novel drugs are typically used for treating disease that is refractory to or has relapsed after cytotoxic therapy, it is likely that they will start being used as part of frontline therapy, either by themselves or in combination with chemotherapy.

Potential new therapeutics for Waldenstrom's macroglobulinemia

Thalidomide the first commercially available immune modulatory drug (IMiD), has activity in the treatment of Waldenstrom's macroglobulinemia (WM), as well as multiple myeloma, myelodysplastic syndrome, myelofibrosis with myeloid metaplasia, chronic lymphocytic leukemia (CLL), and B-cell lymphomas. Although its molecular mechanisms of action have not yet been elucidated, thalidomide and the IMiDs affect a variety of cytokines and inflammatory mediators including tumor necrosis factor-alpha (TNFalpha), interleukin (IL)-1beta, interferon gamma (IFNgamma), IL-6, IL-10, IL-12, and COX-2 and angiogenesis factors such as vascular endothelial growth factor (VEGF) and its receptor. The IMiDs also affect adhesion molecules such as ICAM-1, ICAM-2, and L-CAM, in addition to preferentially stimulating CD8 cells and expanding natural killer (NK) cell populations. Since most IMiDs share these properties, it would be expected that the second-generation IMiDs (REVIMID, ACTIMID) would have activity similar to thalidomide in WM with an improved safety profile. TNFalpha and angiogenesis most likely play a role in promoting the growth and development of WM. The selective cytokine inhibitory drugs (SelCIDs) are potent phosphodiesterase 4 (PDE-4) inhibitors that inhibit TNFalpha production and are highly antiangiogenic. In addition, inhibition of PDE-4 induces apoptosis in human CLL lymphocytes. It is therefore expected that the SelCIDs might have activity in Waldenstrom's tumors. Jun N-terminal kinase (JNK) is a component of signaling cascades that modulate apoptosis, the induction of an inflammatory response via the AP-1 pathway, and modulation of cellular proliferation. In a variety of tumors, including multiple myeloma, JNK is induced as part of a protective mechanism. It is hypothesized that inhibition of JNK activity might allow other chemotherapeutic agents to be more effective in a similar manner to corticosteroids. Work is in progress to evaluate this. Inhibitors of the E3 subunit of ubiquitin ligase may also selectively modulate the expression of receptors, growth factors, and transcription factors essential to the growth, survival, and spread of tumors. We hypothesize that the IMiDs, SelCIDs, JNK inhibitors, and ligase inhibitors will be the basis for a new nonchemotherapeutic approach to the treatment of WM and other related diseases.

Thalidomide and a thalidomide analogue drug costimulate virus-specific CD8+ T cells in vitro

CD8(+) T cell immunity is critical for protection from viral disease, such as that caused by the human immunodeficiency virus (HIV) or cytomegalovirus (CMV). It is therefore important to identify therapies that can boost antiviral immunity. The recent finding that thalidomide acts as a T cell costimulator suggested that this drug may boost antiviral CD8(+) T cell responses. In this in vitro study, in a human autologous CD8(+) T cell/dendritic cell (DC) coculture system, thalidomide and a potent thalidomide analogue were shown to enhance virus-specific CD8(+) T cell cytokine production and cytotoxic activity. The drug-enhanced antiviral activity was noted in cells from both healthy donors and persons chronically coinfected with HIV and CMV. This stimulatory effect was directed at CD8(+) T cells, and not DCs. These results suggest an application for thalidomide and the thalidomide analogue as a novel immune-adjuvant therapy in chronic viral infections.

Moving disease biology from the lab to the clinic

Multiple myeloma (MM) cells home to and adhere to extracellular matrix proteins and to bone marrow stromal cells (BMSCs); and in the BM microenvironment, grow, survive, resist drugs, and migrate under the influence of cytokines including interleukin-6, vascular endothelial growth factor, tumor necrosis factor alpha, and insulin-like growth factor (IGF)-1. Proliferation is via the Ras/Raf MAPK cascade, drug resistance via PI3-K/Akt signaling, and migration via PKC dependent pathways. Novel therapies that target not only the MM cell, but also the BM microenvironment, can overcome drug resistance in vitro and in vivo in murine human MM models. For example, immunomodulatory derivatives of thalidomide (IMiDs) and the proteasome inhibitor PS-341 both induce apoptosis of MM cell lines and patient cells refractory to melphalan, doxorubicin, and dexamethasone; abrogate MM cell binding to fibronectin and BMSCs and related protection against immune- and drug-induced apoptosis; block production of cytokines which promote MM cell growth, survival, drug resistance, and migration; inhibit angiogenesis; and stimulate host anti-tumor immunity. In the setting of relapsed refractory MM, a Phase I trial of the IMiD CC5013 shows stable paraprotein or better in 20 of 24 (79%) patients, with a favorable toxicity profile. In this same patient population 85% of 54 patients treated in a Phase II trial of PS-341 achieved either paraprotein response (50%) or stable disease (35%). Cellular and gene microarray studies comparing PS-341 and an IkappaB kinase inhibitor, PS-1145, suggest that selective NF-kappaB blockade cannot account for all the anti-MM activity of PS-341. Finally, cellular and signaling studies provide the preclinical rationale for combining these novel agents with conventional therapies, or with each other, to enhance efficacy. These novel therapeutics therefore represent a new treatment paradigm in MM targeting the tumor cell in its microenvironment to overcome classical drug resistance and improve patient outcome. Future studies should define the utility of these agents as primary therapy, treatment for first relapse, and maintenance therapy.

High-dose therapy and immunomodulatory drugs in multiple myeloma

The principle of alkylating agent dose intensity, especially with melphalan-based tandem autotransplants, has been effective in increasing the rate of complete remission beyond 40% and effecting 10-year survivorship in about 40% of the three fourths of patients presenting without cytogenetic abnormalities (Total Therapy I). Further dose escalation and post-transplant consolidation therapy, as practiced with Total Therapy II, seems to further improve results in these patients, but not in those with chromosome 13 abnormalities or lactate dehydrogenase elevation. Phase III trials for post-transplant relapse indicate higher complete remission and near-complete remission rates among patients randomized to thalidomide added to dexamethasone versus dexamethasone alone. In a phase I/II study, thalidomide derivative CC-5013, with less sedative and neurotoxic effects, promoted responses in eight of 15 patients with post-transplant relapse, refractory to other salvage therapies, at dose levels of > or = 25 mg daily. Based on a profound graft-vs-myeloma effect with allografts, mini-allotransplants were evaluated in 31 high-risk patients with cytogenetic abnormalities and prior autotransplants; all nine with responsive disease and only one prior autotransplant remain disease-free and alive. Such mini-allotransplants are now offered as consolidation after one standard autotransplant to patients with cytogenetic abnormalities. The systematic application of gene expression profiling attempts to classify multiple myeloma (MM) patients according to molecular features and to dissect the genetic basis for drug sensitivity or resistance. Given the availability of an expanding treatment armamentarium (eg, thalidomide, CC-5013, the proteasome inhibitor PS-341, farnesyltransferase inhibitors, IL-6 receptor antibody, endothelial receptor inhibitor), gene expression profiling is anticipated to help in the selection of agents with the greatest probability of activity toward individualized treatment. Careful scrutiny of gene expression will also help in the identification of unrecognized targets for therapeutic intervention.

Thalidomide and its analogues have distinct and opposing effects on TNF-alpha and TNFR2 during co-stimulation of both CD4(+) and CD8(+) T cells

Thalidomide (Thd) is clinically useful in a number of conditions where its efficacy is probably related to its anti-TNF-alpha activity. More recently, Thd has also been shown to co-stimulate T cells and second generation co-stimulatory (IMiD trade mark ) analogues are currently being assessed in the treatment of cancer patients. However, in contrast to their known suppressive effects during inflammatory stimuli, the effects of Thd/IMiDs on TNF-alpha and TNF receptors (TNFRs) during T cell co-stimulation are not known. We sought to determine the effect of Thd, two clinically relevant IMiDs (CC-4047, ACTIMID trade mark and CC-5013, REVIMID trade mark ) and a non-stimulatory SelCID analogue (CC-3052) on TNF-alpha production and on the expression and shedding of TNFRs during co-stimulation. We found that co-stimulation of PBMC with Thd/IMiDs, but not CC-3052, prevented alphaCD3-induced T cell surface expression of TNFR2 and thereby reduced soluble TNFR2 (sTNFR2) levels. However, there was no effect on total (surface/intracellular) TNFR2 protein expression, suggesting inhibition of trafficking to the cell membrane. The extent of co-stimulation by Thd/IMiDs (assessed by CD69/CD25 expression and IL-2/sIL-2Ralpha production) was similar for CD4+ and CD8+ T lymphocytes and correlated with TNFR2 inhibition. Co-stimulation, but not the early inhibitory effect on TNFR2, was IL-2-dependent and led to increased TNF-alpha production by both CD4+ and CD8+ T lymphocytes. The clinical relevance of this observation was confirmed by the elevation of serum TNF-alpha during REVIMID trade mark treatment of patients with advanced cancer. Together, these results suggest a possible role for TNF-mediated events during co-stimulation and contrast with the TNF inhibitory effects of Thd and its analogues during inflammatory stimuli.

Immunomodulatory drug CC-5013 overcomes drug resistance and is well tolerated in patients with relapsed multiple myeloma

Thalidomide (Thal) can overcome drug resistance in multiple myeloma (MM) but is associated with somnolence, constipation, and neuropathy. In previous in vitro studies, we have shown that the potent immunomodulatory derivative of thalidomide (IMiD) CC-5013 induces apoptosis or growth arrest even in resistant MM cell lines and patient cells, decreases binding of MM cells to bone marrow stromal cells (BMSCs), inhibits the production in the BM milieu of cytokines (interleukin-6 [IL-6], vascular endothelial growth factor [VEGF], tumor necrosis factor-alpha [TNF-alpha]) mediating growth and survival of MM cells, blocks angiogenesis, and stimulates host anti-MM natural killer (NK) cell immunity. Moreover, CC-5013 also inhibits tumor growth, decreases angiogenesis, and prolongs host survival in a human plasmacytoma mouse model. In the present study, we carried out a phase 1 CC-5013 dose-escalation (5 mg/d, 10 mg/d, 25 mg/d, and 50 mg/d) study in 27 patients (median age 57 years; range, 40-71 years) with relapsed and refractory relapsed MM. They received a median of 3 prior regimens (range, 2-6 regimens), including autologous stem cell transplantation and Thal in 15 and 16 patients, respectively. In 24 evaluable patients, no dose-limiting toxicity (DLT) was observed in patients treated at any dose level within the first 28 days; however, grade 3 myelosuppression developed after day 28 in all 13 patients treated with 50 mg/d CC-5013. In 12 patients, dose reduction to 25 mg/d was well tolerated and therefore considered the maximal tolerated dose (MTD). Importantly, no significant somnolence, constipation, or neuropathy has been seen in any cohort. Best responses of at least 25% reduction in paraprotein occurred in 17 (71%) of 24 patients (90% confidence interval [CI], 52%-85%), including 11 (46%) patients who had received prior Thal. Stable disease (less than 25% reduction in paraprotein) was observed in an additional 2 (8%) patients. Therefore, 17 (71%) of 24 patients (90% CI, 52%-85%) demonstrated benefit from treatment. Our study therefore provides the basis for the evaluation of CC-5013, either alone or in combination, to treat patients with MM at earlier stages of disease.

Use of IMiD3, a thalidomide analog, as an adjunct to therapy for experimental tuberculous meningitis

Tuberculous meningitis (TBM), the most severe form of Mycobacterium tuberculosis infection in humans, is associated with significant morbidity and mortality despite successful treatment with antituberculous drugs. This is due to the irreversible brain damage subsequent to the local inflammatory response of the host to M. tuberculosis. Corticosteroids have been used in conjunction with antituberculous therapy in an attempt to modulate the inflammatory response, but this strategy has been of limited success. Therefore, we examined whether combining antituberculous drugs with the immunomodulatory drug thalidomide or with a new thalidomide analog, immunomodulatory drug 3 (IMiD3), would be effective in reducing morbidity and mortality in an experimental rabbit model of TBM. Intracisternal inoculation of 5 x 10(4) CFU of Mycobacterium bovis Ravenel in rabbits induced progressive subacute meningitis characterized by high cerebrospinal fluid (CSF) leukocytosis, protein influx, release of tumor necrosis factor (TNF), substantial meningeal inflammation, and mortality by day 28. Treatment with antituberculous drugs or with antituberculous drugs plus thalidomide improved the clinical course of disease somewhat and increased survival to about 50%. In contrast, treatment with antituberculous drugs in combination with IMiD3 limited pathological neurologic changes and resulted in marked improvement (73%) in survival. IMiD3 treatment was also associated with reduced leukocytosis in the CSF and significantly lower levels of TNF in CSF and plasma. Histologically, the meningeal inflammation in animals treated with antituberculous drugs plus IMiD3 was considerably attenuated compared to that of the other treatment groups. These results suggest a potential role for IMiD3 in the management of TBM in patients.