Treatment of mycosis fungoides with recombinant interferon-alpha 2a2 alone and in combination with etretinate

The Use of Interferons in the Treatment of Cutaneous T-Cell Lymphoma

Interferons are polypeptides that naturally occur in the human body as a part of the innate immune response. By harnessing these immunomodulatory functions, synthetic interferons have shown efficacy in combating various diseases including cutaneous T-cell lymphoma. This article closely examines the qualities of interferon alfa and interferon gamma and the evidence behind their use in the 2 most common types of cutaneous T-cell lymphomas, namely, mycosis fungoides and Sézary syndrome.

Systematic review of combination therapies for mycosis fungoides

BACKGROUND

A variety of therapeutic options are available for mycosis fungoides, the most prevalent subtype of cutaneous T cell lymphomas, but thus far, no regimen has been proven to be curative. A combination of treatments is a well-established strategy to increase the therapeutic efficacy. However, data from clinical trials analyzing such combinations for the treatment of mycosis fungoides are scarce.

OBJECTIVE

To analyze the available evidence on combination therapies with emphasis on the combination of psoralen with UVA phototherapy (PUVA), interferon-alpha and bexarotene with another treatment.

METHODS

Systematic literature review of the databases Embase, Cochrane, Medline, and Medline in Process.

RESULTS

Combination of PUVA with interferon-alpha or retinoids did not result in an increased overall response rate. Addition of methotrexate but not retinoids to interferon-alpha may increase the overall response rate. Bexarotene was investigated in one trial each with vorinostat, methotrexate or gemcitabine, whereby only methotrexate possibly enhanced the effect of bexarotene.

CONCLUSION

For mycosis fungoides, no combination treatment has been demonstrated to be superior to monotherapy. Based on our analysis, we conclude that in certain clinical situations, patients may benefit from a combination of PUVA with interferon-alpha or a retinoid or a combination of the latter two. Furthermore, patients in advanced stages may benefit from the combination of methotrexate and interferon-alpha or bexarotene. Finally, the combination of bexarotene with either vorinostat or gemcitabine did not increase the overall response rate but resulted in more pronounced side effects and cannot be recommended.

Evolving insights in the pathogenesis and therapy of cutaneous T-cell lymphoma (mycosis fungoides and Sezary syndrome)

Cutaneous T-cell lymphomas (CTCL) are a heterogeneous group of malignancies derived from skin-homing T cells. The most common forms of CTCL are Mycosis Fungoides (MF) and Sezary Syndrome (SS). Accurate diagnosis remains a challenge due to the heterogeneity of presentation and the lack of highly characteristic immunophenotypical and genetic markers. Over the past decade molecular studies have improved our understanding of the biology of CTCL. The identification of gene expression differences between normal and malignant T-cells has led to promising new diagnostic and prognostic biomarkers that now need validation to be incorporated into clinical practice. These biomarkers may also provide insight into the mechanism of development of CTCL. Additionally, treatment options have expanded with the approval of new agents, such as histone deacetylase inhibitors. A better understanding of the cell biology, immunology and genetics underlying the development and progression of CTCL will allow the design of more rational treatment strategies for these malignancies. This review summarizes the clinical epidemiology, staging and natural history of MF and SS; discusses the immunopathogenesis of MF and the functional role of the malignant T-cells; and reviews the latest advances in MF and SS treatment.

Cutaneous T-Cell Lymphoma: A Paradigm for Biological Therapies

Mycosis Fungoides and Sézary Syndrome are the most common types of cutaneous T-cell lymphomas. There is no current standard of care for Mycosis Fungoides/Sézary Syndrome, with a general tendency to rely on topical interventions for early disease delaying systemic, more toxic therapy until the development of extensive symptoms. Knowledge of the biological characteristics of this disease has allowed for the development of rational interventions and a significant advance in its treatment. Retinoids are active in Mycosis Fungoides/Sézary Syndrome with the newer rexinoids being available in topical and systemic forms. Interferon alpha remains one of the most active therapeutic agents for Mycosis Fungoides/Sézary Syndrome, especially in combination with other agents such as PUVA. The monoclonal antibody alemtuzumab leads to responses in at least half of patients with advanced disease with its side effect profile consisting mainly of immunosupression and infusion reactions. The recombinant IL2-diphteria toxin denileukin diftitox (Ontak) is active in this disease and appears to have a beneficial effect in symptoms relief and quality of life. Extracorporeal photochemotherapy as an immunostimulating intervention seems to be very effective in a subset of patients, but its availability is limited to less than a hundred centers worldwide. Experimental and less studied interventions include autologous and allogeneic peripheral stem cell transplantation, Interleukin-12, the histone-deacetylator depsipeptide and the synthetic deoxynucleotide CpG7909. Cutaneous T-cell lymphoma has served as a paradigm for the development of biological agents. Further knowledge of the signaling pathways in Mycosis Fungoides/Sézary Syndrome will allow for the development of more effective treatment strategies.

Use of recombinant human interferon alpha-2a in the management of a dog with epitheliotropic lymphoma

An 8-year-old, mixed-breed dog with preputial epitheliotropic lymphoma was initially treated with cyclophosphamide, vincristine, and prednisolone. A short-term partial response was followed by disease progression after 4 weeks. Recombinant human interferon alpha-2a was administered starting at week 7. The interferon therapy resulted in rapid resolution of clinical signs and a 10-week disease-free interval. The lymphoma recurred at 17 weeks and did not respond to rescue chemotherapy. Additional oral lesions were treated with localized radiotherapy followed by increased dosages of interferon. This additional interferon treatment resulted in another 12 weeks of stable disease.

Treatment of cutaneous T-cell lymphoma with retinoids

Retinoids are biologic regulators of differentiation, proliferation, apoptosis, and immune response. Retinoids (all-trans retinoic acid, 13-cis-retinoic acid, and the synthetic analogs isotretinoin, etretinate, and acitretin) have been used for years as monotherapy and/or in combination for treatment of cutaneous T-cell lymphomas (CTCL). Orally administered bexarotene, the first synthetic highly selective retinoid X receptor retinoid to be approved by the Food and Drug Administration for CTCL, was shown to be active against the cutaneous manifestations of all stages of CTCL. The topical gel formulation was also effective for early cutaneous manifestations of CTCL or as an adjunct to systemic or phototherapy. Use of retinoids in future long-term clinical trials and their eventual application in CTCL regiments will require strategies to decrease the side effects of existing retinoids, identify novel receptor subtype-selective retinoids with better therapeutic index, and explore biologically based synergistic combination therapies with other active agents.

Treatment of Mycosis Fungoides with Denileukin Diftitox and Oral Bexarotene

Cutaneous T-cell lymphomas, including mycosis fungoides and Sezary syndrome, are often responsive to treatment, but current therapies have not been shown to increase survival, and in advanced stages, durable remissions are hard to achieve. We present a patient who was initially misdiagnosed with psoriasis and, 16 years later, was diagnosed with mycosis fungoides. Denileukin diftitox was used as a tumor debulking agent to give a partial response that was further improved with a combination of systemic interferon/oral bexarotene and skin-directed psorlen plus UV-A. The purpose of this case report is to show the value of sequential combination therapy for improving overall response.

Interferon in the treatment of cutaneous T-cell lymphoma

Interferons are polypeptides with a broad range of in vivo effects that have shown efficacy in cutaneous T-cell lymphoma (CTCL). Particularly useful is alfa interferon (IFN) which, as a single agent, has shown partial remission rates of > 50% and complete responses of > 20%. Side-effects are predictable, generally well tolerated and dose-related. The efficacy of IFN has increased with combination therapy without any significant increase in attendant side-effects. An update on the specifics of the different IFN subtypes, their inherent biologic activity, pharmacokinetics, efficacy and safety in CTCL is presented in this paper.

Low-dose oral bexarotene in combination with low-dose interferon alfa in the treatment of cutaneous T-cell lymphoma: clinical synergism and possible immunologic mechanisms

BACKGROUND

For nearly 2 decades clinicians have been treating cutaneous T-cell lymphoma (CTCL) with regimens that combine interferon alfa with retinoid compounds. In December 1999 a new retinoid, bexarotene, was approved by the US Food and Drug Administration for the treatment of CTCL. At the manufacturer's recommended dose of bexarotene (300 mg/m(2) of body surface area), it has proven to be a highly effective therapy for all stages of CTCL. Nevertheless, this dose is typically associated with adverse effects including severe hyperlipidemia. Furthermore, there appears to be no standardization of dosing among physicians who treat CTCL.

OBSERVATIONS

We present 3 representative patients, 2 with erythrodermic CTCL and 1 with follicular mycosis fungoides, who experienced the rapid clearing of skin disease while being treated with a combination of low-dose bexarotene and low-dose recombinant interferon alfa.

CONCLUSIONS

Combining low-dose bexarotene with low-dose interferon alfa was well tolerated and led to rapid improvement in our patients. We review the clinical and biologic basis for this approach.

Activity of interferon-alpha and isotretinoin in patients with advanced, refractory lymphoid malignancies

BACKGROUND

Interferon-alpha (IFN-alpha) and retinoids have shown nonoverlapping toxicity and each has shown antitumor activity in patients with lymphoma. The aim of the current study was to assess the toxicity, safety, and efficacy of IFN-alpha combined with isotretinoin in patients with advanced, refractory lymphoid malignancies.

METHODS

Adults with biopsy-proven advanced lymphoid malignancy were treated. Patients with compromised bone marrow function (platelet counts as low as 30 x 10(9)/L) were eligible. Treatment was comprised of IFN-alpha at a starting daily dose of 3 mega units subcutaneously and isotretinoin orally starting at a dose of 1 mg/kg daily in 2 divided doses.

RESULTS

Forty-four patients were evaluable. Their median age was 57 years (range, 18-82 years). Eighteen patients had advanced cutaneous T-cell lymphoma, 6 patients had peripheral T-cell lymphoma, 14 patients had Hodgkin disease, and 6 patients had a variety of other lymphoid malignancies. Patients with Hodgkin disease had received a median of 6 previous therapies (range, 3-12 therapies) and patients with other lymphoid malignancies had received a median of 4 previous therapies (range, 1-9 therapies). The median duration of treatment was 4 months (range, 0.25-38 months). The overall response rate was 38.6% (complete response in 5 patients [11.3%] and partial response in 12 patients [27.3%]). The median response duration was 3 months (range, 1-95+ months). The most common toxicities were low-grade fever, flu-like symptoms, and fatigue (IFN-alpha effects); dry mouth and skin and hypertriglyceridemia (cis-retinoic acid effects); and thrombocytopenia (which generally occurred in patients with low baseline platelet counts).

CONCLUSIONS

IFN-alpha and isotretinoin combination therapy had antitumor activity and was well tolerated in heavily pretreated patients with lymphoid malignancies.

Prognosis, clinical outcomes and quality of life issues in cutaneous T-cell lymphoma

Although the need for a specific QOL index for MF/SS has been recognized, little work has been done in this area. QOL instruments should address general health concepts, as well as specific issues that are relevant to patients who have MF/SS; a combination of two instruments may be appropriate. Confirming the validity, reliability, and responsiveness to change of a combination of QOL instruments, such as SKINDEX-29 and FACT-G, in patients who have MF/SS will be relevant. For patients who have MF/SS, focusing our efforts on improving the disease and their QOL should translate into improvements that are meaningful to them. Thus, our goal should be to incorporate the findings of QOL research into practice and use the results to guide our practices, as they relate to therapy. Some important considerations are: We must be explicit about what will be done with the information that is obtained about an individual's QOL. We should consider what additional knowledge QOL measures provide that we could not otherwise have. We should be ready for unexpected results, as exemplified by instances where aggressive therapy could result in improved QOL. Although challenges exist in moving forward QOL research in CTCL, the words of wisdom of Tannock bring the concept of QOL into perspective: "When cure remains elusive, it is time to start treating the patient, not just the tumor." A final consideration is that we should not forget the dimension of spirituality, which is especially relevant to patients who have advanced MF/SS. Spirituality is characterized by the capacity to seek purpose and meaning, to have faith, to love, to forgive, and to see beyond current circumstances. Spirituality enables a person to rise above suffering. Unfortunately, research on spirituality is scarce, in part, because of the difficulty in assessing spiritual suffering. Nevertheless, physicians who are caring for patients who have advanced MF/SS should acknowledge the spiritual dimension as an integral component of the dying process.

Cytokine therapy of cutaneous T-cell lymphoma: interferons, interleukin-12, and interleukin-2

It is well accepted that cutaneous T-cell lymphomas (CTCL), including mycosis fungoides and Sézary syndrome, represent lymphomas that are highly responsive to immune modifying agents. Furthermore, the recent emphasis on the use of cytokine-related therapeutics is based upon the exceedingly important role of the host immune response in effecting progression of disease. In this article we discuss the data that support the importance of the host immune response in the control of progression of CTCL and the role that cytokine therapy has in supporting the host immune response and the effects of this approach to induce regression of skin and systemic disease.

Topical and systemic retinoid therapy for cutaneous T-cell lymphoma

Because curative therapies for CTCL are not yet available, short of TSEB in patients who have early-stage disease and allogeneic bone marrow transplantation in patients who have more advanced disease, the goal of current therapies is to prevent progression of MF and to preserve quality of life. The overall conclusion drawn from the studies reported in the literature, is that retinoids as monotherapy, or in combination with other nonaggressive treatment modalities, represent a low-risk treatment alternative that is especially suitable for controlling early stages of MF and other CTCL. A combination of therapies may be more effective in controlling CTCL as shown with IFN-alpha plus retinoids, and, recently, IFN-alpha with bexarotene and other modalities. For example, isotretinoin, followed by TSEB (for stage I to II disease) or preceded by chemotherapy (for stage II and IV disease) and bexarotene plus PUVA or photopheresis plus IFN, gave overall response rates of 82% and 69% in patients who had MF and SS, respectively. Retinoids as monotherapy may induce complete remissions, but usually these responses are of short duration and relapses are common. Clinical response is not identical to histologic clearance. Even in cases with clinically complete clearance of skin lesions, lymphoid infiltrates persisted, which are most likely the source of recurrences. The new generation of retinoids, the RXR selective agonists like bexarotene, represent a promising approach for refractory or persistent MF that is unresponsive to first-line therapies. Individual differences in response to retinoids may be due to different expression of retinoid receptors, functional polymorphisms in metabolizing retinoids, or resistance to some retinoids. In the future, pharmacogenomic studies are needed to clarify the mechanisms that underlie the differing response rates of patients who have CTCL to retinoids. In addition, new agonists of RAR and RXR, either selective or pan agonists, will become available and will enlarge the spectrum of vitamin A analogs that have antitumoral properties.

Analysis of long-term outcomes of combined modality therapy for cutaneous T-cell lymphoma

BACKGROUND

Although cutaneous T-cell lymphoma (CTCL), including mycosis fungoides (MF) and Sézary syndrome, is often responsive to treatment, few current therapies increase survival or consistently induce durable remissions, especially in advanced disease.

OBJECTIVE

In an effort to improve treatment efficacy and outcome in CTCL, a combined modality protocol using 3 to 4 consecutive phases of therapy was initiated in 1987 at M.D. Anderson Cancer Center, Houston, Tex.

METHODS

During a period of 15 years between 1987 and 2001, 95 patients with early-stage (Ia-IIa, n = 50) and late-stage (IIb-IVb, n = 45) MF were treated with subcutaneous interferon-alpha and oral isotretinoin, followed by total-skin electron beam therapy, and long-term maintenance therapy with topical nitrogen mustard and interferon-alpha. Patients with late-stage (IIb-IVb) disease also received 6 cycles of combination chemotherapy before electron beam therapy.

RESULTS

Combined modality therapy yielded a response rate of 85% with a 60% complete response rate. Among 38 patients with early-stage disease and 18 patients with late-stage disease achieving complete response, 9 (24%) patients with early-stage MF and 3 (17%) patients with late-stage MF achieved sustained remissions lasting more than 5 years. The median disease-free survival (DFS) for early and late stages of disease was 62 and 7 months, with 5-year Kaplan-Meier estimated rates of 50% and 27%, respectively. Current median overall survival times on combined modality are 145 months for patients with early-stage disease and 36 months for those with late-stage disease. Death was attributable to CTCL disease in 17 (55%) of 31 cases. The Kaplan-Meier estimates for 5-year survival are 94% for early-stage and 35% for late-stage disease. Univariate survival analysis in this patient population reveals statistically significant associations of clinical stage with overall response rates (P =.02), DFS (P =.03), and overall survival (P <.0001); age with DFS (P =.001) and overall survival (P =.04); and T stage (P <.0001) and lactate dehydrogenase (P =.007) with overall survival. By multivariate analysis using a Cox proportional hazards model, only age was significantly associated with DFS (hazard ratio 2.9), and only stage with overall survival (hazard ratio 18.2).

CONCLUSION

This nonrandomized and uncontrolled CTCL study gives supportive evidence that this multiphased combined modality regimen is well tolerated and may yield higher response rates and DFS than total-skin electron beam therapy alone, but provides no evidence for a change in survival.

Combination of 13-cis retinoic acid and interferon-alpha in the treatment of recurrent or refractory peripheral T-cell lymphoma

We previously reported the therapeutic efficacy of 13-cis retinoic acid (13-cRA) in some subtypes of peripheral T-cell lymphoma (PTCL). This study sought to clarify if the addition of interferon-alpha2a (IFN-alpha2a), an agent with synergistic cytotoxicity with 13-cRA in many types of malignant cells, may be more effective in the treatment of PTCL. Eligible patients has histologically proven PTCL, which was recurrent after or refractory to anthracycline-containing systemic chemotherapy. The treatment included oral administration of 13-cRA 1 mg/kg/day, divided into three doses, and intramuscular injection of IFN-alpha2a 4.5 MU/M2, three times per week. From March 1995 to July 2000, a total of 17 patients, 10 men and 7 women, with a median age of 47 years (range, 18-77 years), were recruited. The histologic diagnosis included 7 cases of unspecified PTCL, 6 cases of Ki-1 anaplastic large cell lymphoma (ALCL), 1 case of angioimmunoblastic T-cell lymphoma, and 3 cases of angiocentric nasal NK/T cell lymphoma. They received a median of 1.7 months of treatment (range, 0.4-13.3 months). One patient refused further treatment due to toxicity. The doses of 13-cRA and IFN-alpha2a had to be decreased in 7 and 7 patients, respectively. Grade III/IV hematologic and non-hematologic toxicity developed in 2 and 5 patients, respectively. There were 5 partial responses (Ki-1, 4; unspecified PTCL, 1), with a total response rate of 31.3% (95% CI, 5.7-56.8%). The median duration of response for the responders was 2.5 months (range, 0.8-7.2 months). The median overall survival for the entire group of patients was 3.6 months. In conclusion, a combination of 13-cRA and IFN-alpha2a is a useful salvage treatment for selected patients with recurrent or refractory PTCL, particularly those with the Ki-1 subtype. However, the data does not support that addition of IFN-alpha2a is superior to 13-cRA alone.

Treatment of cutaneous T cell lymphoma: current status and future directions

The treatment of cutaneous T cell lymphoma (CTCL), which includes mycosis fungoides and Sezary syndrome, has been in a state of continual change over recent decades, as new therapies are constantly emerging in the search for more effective treatments for the disease. However, prognosis and survival of patients with CTCL remains dependent upon overall clinical stage (stage IA-IVB) at presentation, as well as response to therapy. Past therapies have been limited by toxicity or the lack of consistently durable responses, and few treatments have been shown to actually alter survival, especially in the late stages of disease. Even aggressive chemotherapy has not been shown to improve overall survival compared to conservative sequential therapy in advanced disease, and adds the risk of immunosuppressive complications. Over the last decade, extracorporeal photopheresis has been the only single treatment that has been shown to improve survival in patients with Sezary syndrome, although its true efficacy and place in combination therapy remain unclear. Much of the focus of current research has been on combinations of skin-directed therapies and biological response modifiers, which improve response rates. The results of various trials over the years have also brought into favor the use of post-remission maintenance therapy with topical corticosteroids, topical mechlorethamine (nitrogen mustard), interferon-alpha, or phototherapy to prevent disease relapse. Recent novel developments in CTCL therapy include oral bexarotene, a retinoid X receptor-selective retinoid that has activity in all stages of CTCL, and the topical gel formulation of bexarotene, which plays a role in treating localized lesions. US Food and Drug Administration (FDA)-approved, oral systemic bexarotene has the advantage of a 48% overall response rate at a dosage of 300 mg/m(2)/day, and avoids immunosuppression and risk of central line and catheter-related infectious complications that are associated with other systemic therapies. Monitoring of triglycerides and use of concomitant lipid-lowering agents and thyroid replacement is required in most patients. Also recently FDA-approved, denileukin diftitox is the first of a novel class of fusion toxin proteins and is selective for interleukin-2R (CD25+) T cells, targeting the malignant T cell clones in CTCL. Denileukin diftitox is associated with capillary leak syndrome in 20 to 30% of patients, which may be ameliorated by hydration and corticosteroids. Higher response rates are possible by combining bexarotene with "statin" drugs and active CTCL therapies. Studies are being conducted on combining bexarotene and denileukin diftitox with other modalities. Biological response modifier therapies that are in current or future investigational trials include topical tazarotene, pegylated interferon, interleukin-2, and interleukin-12. At the forefront of systemic chemotherapy development, pegylated liposomal doxorubicin, gemcitabine, and pentostatin appear to have the greatest potential for success in CTCL therapy. Bone marrow transplantation, which is currently limited by the risk of graft-versus-host disease, offers the greatest potential for disease cure. Further developments for CTCL may include more selective immunomodulatory agents, vaccines, and monoclonal antibodies.

Cutaneous T-cell lymphoma. New immunomodulators

During the most recent decades, much knowledge has been gained concerning the immunologic and pathologic mechanisms of CTCL. The development of immunomodulators aimed at correcting aberrations in immunology and cellular growth and differentiation reflects this increased understanding. This review of the currently available immune-response modifying drugs shows that recombinant forms of natural cytokines and retinoids can be developed with tolerable toxicity profiles and substantial efficacy. Although milestone drugs such as bexarotene have been approved by the FDA- for treatment of CTCL, other agents such as IL-12 may also have a place in treatment of the disease. Even though unapproved, IFN-alpha may be the most active single immunomodulating agent against CTCL. It seems that further delineation of CTCL cytokine profile changes and immunologic aberrations are key in developing effective immunomodulators that are able to reverse these alterations.

Historical perspective on the use of retinoids in cutaneous T-cell lymphoma (CTCL)

Vitamin A and its analogues influence differentiation and proliferation and may also alter immune responses. Limited clinical efficacy of these compounds given alone or as part of a combination therapy has been shown in various types of cutaneous T-cell lymphoma (CTCL), including mycosis fungoides, Sézary syndrome, and prelymphomatous disorders such as parapsoriasis en plaques. Compounds used mostly in small, nonrandomized trials are isotretinoin (13-cis-retinoic acid), etretinate, acitretin, and all-trans-retinoic acid. Clinical responses have been found despite persistent residual disease with atypical lymphocytes in various compartments. The exact mechanism of action of retinoids in CTCL is unclear and depends on the presence of retinoid receptors on the tumor cells, which is variable in different forms of CTCL. Therapies combining retinoids with psoralen-ultraviolet A or with interferons may have a synergistic effect, which deserves confirmation through randomized trials in the future.

Long-term follow-up in 51 patients with mycosis fungoides and Sézary syndrome treated by interferon-alfa

Although interferon-alfa (IFN-alpha) has proved effective in treating epidermotropic cutaneous T-cell lymphoma (ECTL), few studies have considered the follow-up of treated patients and whether complete remission was maintained. We studied 51 patients (one stage Ia, seven stage Ib, one stage IIa, 30 stage IIb, 11 stage III (Sézary syndrome) and one stage IV) who received low-dose IFN-alpha as monotherapy for ECTL (mean daily dose of IFN-alpha 2.7 x 106 units for 14.9 months), giving special consideration to the significance of My7 (CD13) antigen expression by epidermal basal cells in predicting the maintenance of complete remission. For a mean follow-up period of 43.4 months, the results showed 21 complete remissions, 13 partial remissions and 17 patients with stable or progressive disease. Twelve patients died during the follow-up (3-52 months). IFN-alpha led to an improved response in the early stages, with a greater number of complete remissions (P = 0.03) and partial remissions (P = 0.01). The mean time to complete remission was 4 months, regardless of clinical stage (P = 0.1). Of 21 patients in complete remission, 57% had a relapse within a mean period of 7.5 months. For patients maintained in complete remission, the mean period of response was 31 months. The length of complete remission was independent of clinical stage, and My7 antigen expression was not predictive of complete remission.

Systemic retinoids. What's new?

Despite major advances in the molecular biology and pharmacology of retinoids, no new compound has been developed for systemic use. This article addresses some questions related to the indications of oral retinoids already on the market, e.g. isotretinoin, acitretin, as well as tretinoin, reviews some recently reported undesirable effects, and discusses the recent concepts generated by basic research that may lead to new drugs to be used in pharmacology.

Interferons in dermatology. Present-day standard

Since the first clinical trials in the early 1980s with recombinant interferon, it was possible to show for a variety of indications that cytokines, especially interferons, at certain doses and at respective intervals, when applied in combination with other pharmaceutical compounds open new powerful therapeutic possibilities. Worldwide, recombinant interferon is licensed, especially in dermato-oncology, for the indication of HIV-associated Kaposi's sarcoma, cutaneous T-cell lymphoma, and recently for adjuvant therapy of high-risk malignant melanoma. Recombinant interferon is at present not licensed for dermatologic indication (septic granulomatosis). At the end of our century the indication spectrum for interferons as monotherapy and as combination therapy will undoubtedly be extended. Larger and controlled studies will prove the importance of interferons in dermato-oncology as well as in inflammatory and infectious dermatoses. The combination of interferons with standard therapies will surely be of the utmost importance in dermatotherapy.

Perspectives of cytokine treatment in malignant skin tumors

Cytokines have been tested in the treatment of different skin cancers during the last decade, and treatment schedules have been established or proposed for several malignant skin tumors. Preferentially, the interferons and interleukin-2 were found to be effective in treating skin cancers. Interferons alpha and beta have been approved for the treatment of human immunodeficiency virus (HIV)-associated Kaposi's sarcoma, cutaneous T cell lymphoma, and malignant melanoma in several countries. Interferon alpha was found to be most effective in cutaneous T cell lymphoma with 40%-60% overall responses. When combining interferon alpha with psoralens and ultraviolet A (PUVA) or with retinoids, even higher response rates up to 60%-90% were reported, and long-term remissions have been described. A considerable activity of interferon alpha was found in HIV-associated Kaposi's sarcoma with response rates of 30%-50%. The effectiveness of Kaposi's sarcoma's treatment was further improved by combining interferon alpha and zidovudine. Responses to interferon alpha in metastatic malignant melanoma are rather seldom (10%-15%), but a stabilization of the disease with prolonged survival was reported after interferon alpha treatment. Additionally, interleukin-2 was found to be active in metastatic melanoma, with overall response rates of about 20%, and both biological agents were found to have an additive efficacy in combination. Several combined regimens of interferon alpha, interleukin-2, and polychemotherapy have been described in metastatic melanoma, and overall response rates higher than 50% were found with these combined treatment modalities. Interferon alpha and beta were also intralesionally injected into basal cell carcinomas and other epithelial skin cancers, and complete responses were found in more than 80% of tumors treated. Local applications of interferons and interleukin-2 were likewise found to be effective in the treatment of cutaneous melanoma metastases and cutaneous manifestations of Kaposi's sarcoma. Cytokines and their combination with other treatment modalities has greatly enriched the treatment facilities in malignant skin tumors during recent years, and additional new cytokines will be introduced in skin cancer treatment in near future.

Combination therapy of cutaneous T cell lymphoma with interferon alpha-2a and photochemotherapy

The efficacy of a combination treatment with interferon alpha-2a and photochemotherapy was investigated in 16 patients with cutaneous T cell lymphoma. During the initial treatment, interferon alpha-2a was given subcutaneously at maximum dose of 9 million IU. Simultaneously, photo-chemotherapy with a maximum single dose of 3.0 J/cm2 was applied. After a complete or partial remission had been achieved, the dose of interferon was continued as permanent treatment at 3-9 million IU a week. Photochemotherapy was maintained twice a week for a minimum of 2 months and then stopped depending on the course of the disease. The combination treatment was well tolerated and all patients responded to the initial therapy. Three patients were withdrawn at an early stage of therapy, as they developed erythrodermia after photochemotherapy. The permanent treatment led to a complete remission in ten out of 13 patients and to a partial remission in three patients. During the follow-up period (now 10-40 months), therapy was stopped in four patients because of progression and in one patient because of newly diagnosed Hodgkin's disease. In another three patients, who developed local recurrences, a repetition of the initial treatment schedule was necessary to keep them in remission.

Interferon treatment of cutaneous T-cell lymphoma

In this report we have reviewed studies on the clinical effect of the interferon (IFN) treatment of 304 patients suffering from cutaneous T-cell lymphoma (CTCL). Intramuscular, subcutaneous or intralesional administration of recombinant IFN has been used as monotherapy or as part of combination therapy. In general, IFN has proved to be a relatively effective agent in the treatment of CTCL, and the best responses have been achieved in the early stages of the disease. In CTCL the overall response rate to IFN including complete, partial and minor responses is 70%. Neither the doses nor the routes of administration in these studies has any statistically significant influence on the clinical response to IFN treatment. Continuous low-dose IFN therapy, presumably in combination with psoralen and UVA light (PUVA), is recommended. This review concludes that the clinical stage of disease before treatment is the only known predictive parameter concerning the clinical response to IFN treatment in patients with CTCL.

Roferon-A (interferon alpha 2a) combined with Tigason (etretinate) for treatment of cutaneous T cell lymphomas

Many treatments are used for epidermotropic cutaneous T cell lymphomas (CTCL) such as mycosis fungoides (MF) and Sézary syndrome (SS). All pretend to be effective, but none is really curative. As single drug therapy provides a response rate of about 55% with interferon alpha and about 45% with etretinate, we studied the effectiveness of combining these two drugs for immunomodulatory therapy in epidermotropic CTCL. A review of four reports, including a multicenter study performed in 45 patients, indicates a response rate of 56%, with better results for MF than SS. Side effects are generally moderate when low doses are used. The mechanism of action of this combined therapy on cutaneous lesions remains unclear. In vitro, a synergistic effect of retinoids on interferon alpha antiviral activity has been demonstrated, and in vivo an immunohistochemical study showed that the combined therapy modulates antigens expressed by keratinocytes and increases cytotoxic cells in dermis without modifying the number of Langerhans cells in epidermis.

Intramuscular low dose alpha-2B interferon and etretinate for treatment of mycosis fungoides

BACKGROUND

Mycosis fungoides is a lymphoma of cutaneous origin characterized by a proliferation of cells with a T phenotype.

METHODS

In this pilot study, 13 men with mycosis fungoides in various stages were treated with alpha-2b interferon and etretinate.

RESULTS

In ten of them, such a therapy proved to be effective (7 complete responses, 3 partial responses), sometimes with prolonged remissions (up to 20 months, and still persistent) after suspension of the drugs.

CONCLUSIONS

We chose low-dose interferon administration in order to prevent side effects, which are said to be dose-dependent. In our experience this is not true, but this drawback seems to be overcome by the very good, sometimes spectacular, response to this combination therapy, particularly in low stage forms of the disease. This fact, compared with results provided by other groups, prompts us to plan new research protocols based on associations of retinoids with different interferon types (or even associations of different interferons), because we believe they will have an important place in treatment of cutaneous T-cell lymphoma in future.

Therapeutic alternatives in cutaneous T-cell lymphoma

Mycosis fungoides and Sézary syndrome, collectively referred to as cutaneous T-cell lymphoma, are non-Hodgkin's lymphomas that initially appear in the skin. Early-stage disease, limited to the skin, is best treated with sequential topical therapies such as topical nitrogen mustard, psoralen phototherapy (PUVA), or total-skin electron beam therapy. Photopheresis is the first line of therapy for the patient with erythroderma. Systemic therapy is generally reserved for patients with refractory disease and patients who initially present with extracutaneous involvement. Although there are several treatment options for cutaneous T-cell lymphoma, there have been few randomized comparative trials.

Retinoids in cancer prevention and therapy

Retinoids are a class of compounds structurally related to vitamin A. In preclinical studies, all-trans retinoic acid (tretinoin), 13-cis retinoic acid (isotretinoin) and the aromatic retinoids etretinate and acitretin have preventive and therapeutic effects on carcinogen-induced premalignant and malignant lesions. Clinically, chemoprevention with isotretinoin and etretinate has been tested with some degree of success in such indications as basal cell carcinomas, squamous cell carcinomas, superficial bladder tumors and second primary tumors in patients with squamous cell carcinoma of the head and neck. Limited therapeutic success has also been achieved with retinoid treatment of precancerous and cancerous conditions of the skin, oral cavity, larynx, lung, bladder and vulva. Dramatic therapeutic effects have been observed in the treatment of acute promyelocytic leukemia with tretinoin, which leads to very high rate of complete remission. Excellent results were recently reported in the treatment of squamous cell carcinomas of the skin and cervix with a combination of isotretinoin and recombinant interferon alfa-2a (rIFN alfa-2a, Roferon-A). The mechanism of action of retinoids is through modulation of cell proliferation and differentiation. Retinoids vary in their capacity to induce differentiation and to inhibit proliferation in a series of human transformed hematopoietic and epithelial cell lines. Some cytokines potentiate the retinoid-induced cell differentiation and act synergistically with retinoids to inhibit cell proliferation. The pattern of synergism is dependent upon the combination and tumor cell line tested. The discovery of nuclear retinoid receptors has contributed substantially to the understanding of the mechanism of action of retinoids at the molecular level. Further understanding of the molecular biology of retinoids is expected to contribute to a rational design of new retinoids in the future, which in turn may result in improvements in the prevention and therapy of cancer.

Combined treatment with oral etretinate and electron beam therapy in patients with cutaneous T-cell lymphoma (mycosis fungoides and Sézary syndrome)

BACKGROUND

Total skin irradiation for early-stage mycosis fungoides produces clinical remission in 90% of patients, but the median duration of remission is only 2 to 4 years. Etretinate has proven efficacy in advanced mycosis fungoides. Its potential as adjuvant therapy to radiation could be limited by toxicity from the combination.

OBJECTIVE

Our purpose was to determine whether oral etretinate at 1 mg/kg can be combined with 35 Gy of radiation without intensifying or prolonging the radiation reaction and to determine the relapse-free survival rate.

METHODS

Twenty-three patients began etretinate on day one of radiation and the dose was reduced for nose bleeds, dry skin, or hyperlipidemia. During the reaction skin toxicity questionnaires were completed weekly. Nine concurrent patients receiving only radiation completed identical forms.

RESULTS

Etretinate did not intensify the skin reaction but did prolong it by 2 weeks. At a median follow-up of 2 years the relapse-free survival rate in complete responders was similar to stage-matched concurrent and historic control subjects.

CONCLUSIONS

Both radiation and etretinate can be given together with acceptable toxicity and without compromising either therapy.

Inhibition of proliferation by retinoids, cytokines and their combination in four human transformed epithelial cell lines

Various combinations of retinoids and cytokines were examined for their synergistic effect on inhibition in proliferation of four human transformed epithelial cell lines, MCF7 (mammary carcinoma), SCC4, SCC15 and A431 (squamous cell carcinomas). Synergism depended on the cell line tested, to some degree on the specific retinoid but particularly on the type of cytokine used. IFN alpha had the widest spectrum of activity. IFN gamma, TNF-alpha, IL-1, EGF and TGF-beta also exerted a synergistic effect on proliferation inhibition in certain cell lines, whereas G-CSF was inactive. Association of retinoids and cytokines represents a new approach to antitumor chemotherapy.

The treatment of 45 patients with cutaneous T-cell lymphoma with low doses of interferon-alpha 2a and etretinate

Forty-five patients with cutaneous T-cell lymphomas (CTCL), 32 with mycosis fungoides (MF) and 13 with Sézary syndrome (SS), were treated with interferon-alpha 2a (IFN-alpha 2a) (6-9 x 10(6) IU daily) for 3 months. Those responding to treatment were then treated with interferon-alpha alone (6-9 x 10(6) IU three times weekly), and non-responders received a combination of etretinate (0.5 mg/kg/day) and IFN-alpha 2a in similar concentrations. After 12 months of treatment, 28/45 patients (62.2%) were in complete or partial (greater than 50%) remission. Of these, 17 (60.7%) were receiving IFN-alpha alone and 11 the combined interferon-retinoid therapy. Of the patients with MF stage I and II, 20/25 were responders (12 receiving IFN-alpha alone and eight on combined therapy), whereas only 8/20 with stage IV or SS responded to treatment (five receiving IFN-alpha 2a alone and three combined therapy). These results suggest that the association of etretinate with low-dose recombinant IFN-alpha 2a is an effective means of treating epidermotropic CTCL, particularly in the early stages.

Is interferon alpha in cutaneous T-cell lymphoma a treatment of choice?

This study was designed to evaluate the therapeutic efficacy and toxicity of recombinant interferon alpha-2a (rIFN alfa-2a) given as initial systemic therapy in untreated mycosis fungoides and/or Sezary's syndrome patients, at a slowly escalating schedule up to the maximal tolerated dose. At the same time this schedule was administered in patients who had relapsed or were refractory to previous treatment; 28 newly diagnosed and 15 previously treated patients entered the study. IFN was given daily with dose escalation from 3 to 18 MU. The last follow-up in June 1990 indicates that 90% of previously untreated patients who obtained a complete remission remain in continuous complete remission after 18 to 40 months and that 75% of previously untreated patients who obtained partial remission remain in partial remission after 20-44 months. The event-free survival projected, calculated using the Kaplan and Meier product limit technique, was 21% of all patients at 54.7 months (40% in the previously untreated groups and 14% in the previously treated group: P = 0.12). In conclusion, interferon is very effective as a single agent in cutaneous T-cell lymphomas.

Interferon alpha in lymphoma

A number of studies are currently in progress to evaluate the use of interferon alpha, alone and in combination with conventional chemotherapy in patients with follicular lymphoma. The background to these is reviewed, together with currently available data about the potential role of interferon alpha in cutaneous T cell lymphoma.

Therapeutic use of cytokines in dermatology

Cytokines are glycoproteins produced by many different cells. Via binding to specific receptors on target cells they regulate the activation, differentiation, and proliferation of immune and nonimmune cells. After injury keratinocytes synthesize and release cytokines such as interleukins, colony stimulating factors, and growth factors. In addition, a network of interacting cytokines appears to be crucial to maintain proper balance. Dysregulation may contribute to certain diseases, particularly those of infectious and autoimmune origin. Therefore many of these mediators appear to be promising candidates to treat infectious and malignant diseases. This article briefly discusses the most important cytokines. Newly developed regimens with cytokines to treat cutaneous disorders will be reviewed.

Treatment of cutaneous T cell lymphoma with a combination of low-dose interferon alfa-2b and retinoids

In a pilot study the therapeutic effect and side effect profile of low-dose interferon alfa-2b in combination with a retinoid for the treatment of cutaneous T cell lymphoma were evaluated. Seven patients (four women, three men) with histologically confirmed cutaneous T cell lymphoma were included. Four patients had received therapy previously. The treatment schedule consisted of 2 million U of interferon alfa-2b administered subcutaneously three times per week and oral 13-cis-retinoic acid, 1 mg/kg/day, with subsequent dose reduction in case of response. The combination therapy produced two complete and two partial remissions. Responses were maintained by continuous therapy for up to 15 months even after dose reduction of both agents by 50%. Side effects were negligible and did not result in discontinuation of treatment in any patient.

A case of classical mycosis fungoides associated with human T-cell lymphotropic virus type I

A 72-year-old male patient from north-eastern Iran developed the typical clinical and histopathological features of mycosis fungoides with lymphadenopathy, but without any other systemic involvement. Human T-cell lymphotropic virus (HTLV-I) antibodies were detected in the patient's serum by two different ELISAs and by Western blot using purified viral particles from MT-2 culture supernatants. Cultured peripheral blood lymphocytes were positive for labelling with anti-HTLV-I serum. Southern blot hybridization of DNA extracted from a skin tumour and from an involved lymph node revealed integrated proviral DNA with identical restriction patterns. This case supports a relationship between mycosis fungoides and HTLV-I and may indicate a new region of endemic HTLV-I infection.

Interferon alpha and etretinate combination treatment of cutaneous T-cell lymphoma

Eleven patients suffering from cutaneous T-cell lymphoma (mycosis fungoides) were treated with recombinant interferon alpha-2A in combination (seven patients) or alone. Two patients, one in combined treatment, went into clinical complete remission, and five experienced partial remission. Two patients progressed during therapy, and two were nonevaluable because they stopped treatment early due to side effects. Dosages of interferon were from 3 to 36 million units daily for 3 months, and thereafter 3 times weekly. Etretinate (0.7 mg/kg) was given orally. The study showed that recombinant interferon alpha-2A in combination with etretinate or alone can induce remission of cutaneous T-cell lymphoma.