Sequential Administration of Interferon-γ, GM-CSF, and Interleukin-2 in Patients With Metastatic Renal Cell Carcinoma: Results of a Phase II Trial:

First-line Immune Checkpoint Inhibitor Combinations in Metastatic Renal Cell Carcinoma: Where Are We Going, Where Have We Been?

The combination of targeted therapy and immunotherapy in the treatment of metastatic renal cell carcinoma (mRCC) has significantly improved outcomes for many patients. There are multiple FDA-approved regimens for the frontline setting based on numerous randomized Phase III trials. Despite these efforts, there remains a conundrum of identifying a biomarker-driven approach for these patients and it is unclear how to predict which patients are most likely to respond to these agents. This is due, in part, to an incomplete understanding of how these drug combinations work. The use of tyrosine kinase inhibitors that have multiple 'off-target' effects may lend themselves to the benefits observed when given in combination with immunotherapy. Further, targeting multiple clones within a patient's heterogenic tumor that are responsive to targeted therapy and others that are responsive to immunotherapy may also explain some level of improved response rates to the combination approaches compared to monotherapies. This review highlights the 5 FDA-approved regimens for mRCC in the frontline setting and offers insights into potential mechanisms for improved outcomes seen in these combination approaches.

Granulocyte macrophage-colony stimulating factor plus interleukin-2 plus alpha-interferon plus 5-fluorouracil in the treatment of metastatic renal cell cancer: induction of CD80/86+ T cells indicates adverse outcome

Even in the era of multitargeted therapies, cytokines remain at least one of different treatment options in renal cell cancer (RCC), particularly for patients belonging to the good prognostic risk category according to Memorial Sloan Kettering Cancer Center criteria. Granulocyte macrophage-colony stimulating factor plays a central role in the differentiation and activation of antigen presenting cells. This clinical phase 1/2 chemoimmunotherapy trial in metastatic RCC used sequential application of alpha-interferon /5-fluorouracil followed by granulocyte macrophage-colony stimulating factor/interleukin-2. The study was performed before multikinase inhibitors were available for routine use. Twenty patients with metastatic RCC were enrolled into this phase 1/2 protocol. Sequential chemoimmunotherapy was feasible and safe on an outpatient basis. The regimen had only modest antitumor activity with 4 mixed responses and 4 stable diseases being documented after 4 treatment cycles. Enhanced proliferative and stimulatory capacity of peripheral blood mononuclear cells was only observed in patients with mixed responses/stable diseases whereas patients with progressive disease did not show any change. Most interestingly, there was a significant increase of T cells expressing the costimulatory molecules CD80/86 in patients with progressive disease. This finding is reported here for the first time under chemoimmunotherapy of RCC. In conclusion, clinical response rates of this cytokine-based regimen do not justify further clinical evaluation. However, the study suggests that CD80/86+ T cells might have negative regulatory function under cytokine treatment and are possibly useful as a negative predictive marker for clinical response.

The role of sargramostim (rhGM-CSF) as immunotherapy

GM-CSF stimulates the differentiation of hematopoietic progenitors to monocytes and neutrophils, and reduces the risk for febrile neutropenia in cancer patients. GM-CSF also has been shown to induce the differentiation of myeloid dendritic cells (DCs) that promote the development of T-helper type 1 (cellular) immune responses in cognate T cells. This review summarizes some of the immunological effects of GM-CSF relevant to antitumor immunity in cancer patients. GM-CSF has been used to augment the activity of rituximab in patients with follicular lymphoma and to induce autologous antitumor immunity in patients with hormone-refractory prostate cancer. GM-CSF causes upregulation of costimulatory molecule expression on leukemia blasts in vitro, enhancing their ability to present antigen to allogeneic T cells, and, in combination with interferon-alpha, can induce antitumor immune responses in patients whose acute leukemia has relapsed following allogeneic hematopoietic progenitor cell transplant. Tumor cells engineered to secrete GM-CSF are particularly effective as antitumor vaccines, and the addition of GM-CSF to standard vaccines may increase their effectiveness by recruiting DCs to the site of vaccination. However, a significant limitation in the use of GM-CSF as an immunostimulatory agent is that objective antitumor responses are infrequent, and are often not durable. Effective and durable antitumor immunity will likely require novel methods to eliminate counterregulatory immune responses that limit activation and expansion of cytotoxic T cells with antitumor activity.

Symptom burden among patients with renal cell carcinoma (RCC): content for a symptom index

BACKGROUND

Renal cell carcinoma (RCC) has multiple symptoms stemming from disease and treatments. There are few validated scales for evaluating RCC symptoms.

METHODS

A national cross-sectional study of adult RCC patients was conducted from October to December 2003 to define patient-reported RCC symptomology. Participants were asked open-ended questions regarding their signs and symptoms and completed an 86-item pilot questionnaire of physical and psychological symptoms. Patients were asked to rate the relevancy and clarity of each pilot question using a 5-point Likert scale. Subsequent open-ended caregiver interviews and a provider panel relevance ranking contributed additional information.

RESULTS

The average age of the participants (n = 31) was 55 years; 55% of patients were male, 74% had attended college, and 97% were Caucasian. The five most frequent symptoms among localized-stage patients (n = 14) were irritability (79%), pain (71%), fatigue (71%), worry (71%), and sleep disturbance (64%). Among metastatic patients (n = 17), the five most frequent symptoms were fatigue (82%), weakness (65%), worry (65%), shortness of breath (53%), and irritability (53%). More than 50% of localized and metastatic-stage patients reported pain, weakness, fatigue, sleep disturbance, urinary frequency, worry, and mood disorders as being moderately to highly relevant.

CONCLUSION

A brief, self-administered RCC Symptom Index was created that captures the relevant signs and symptoms of both localized and metastatic patients. Pending additional content validation, the Index can be used to assess the signs and symptoms of RCC and the clinical benefit resulting from RCC treatment.

Immunomodulatory effects of human recombinant granulocyte-macrophage colony-stimulating factor (rhuGM-CSF): evidence of antitumour activity

Human recombinant granulocyte-macrophage colony-stimulating factor (rhuGM-CSF) is traditionally used as supportive care for patients undergoing cytotoxic chemotherapy or haematopoietic cell progenitor mobilisation. Emerging evidence suggests rhuGM-CSF, through activity on monocytes and dendritic cells, acts as a potent modulator of immune responses and has the ability to recruit inflammatory cells and cytokines to local and systemic sites of infection. The immunomodulatory effects of rhuGM-CSF suggest the potential to enhance innate and acquired immune responses against tumour-related antigens. Enhancement of innate antitumour immunity, especially in the context of minimal residual disease, is of central importance and presents the potential for meaningful contributions to long-term disease survival. This article discusses the immunomodulatory effects of rhuGM-CSF in the context of single-agent therapy in solid tumours, as well as combination therapy in lymphoma. In addition, dendritic cell modulation with rhuGM-CSF in haematopoietic progenitor grafts and rhuGM-CSF-transduced tumour vaccines will be discussed.

A Phase 2 Study of Moderate Dose Interleukin-2 and Granulocyte-Macrophage Colony-Stimulating Factor in Patients With Metastatic or Unresectable Renal Cell Carcinoma

Interleukin-2 (IL-2) has been shown to produce durable complete remission in patients with renal cell carcinoma (RCC). A phase 2 study was conducted to evaluate the potential therapeutic synergy as well as the toxic side effects of the concurrent administration of IL-2 and granulocyte-macrophage colony-stimulating factor (GM-CSF) in patients with advanced stage disease. Twenty-one patients with unresectable or metastatic RCC having an Eastern Oncology Cooperative Group performance status of 0 or 1 were enrolled. Six patients had received prior immunotherapy with interferon (IFN)-alpha, IFN-gamma, and IL-12, whereas the remaining 15 subjects were previously untreated. Thirteen patients were assigned to a moderate-dose bolus of IL-2 at 72,000 IU/kg every 8 hours on days 1 through 5 and days 15 through 19, whereas 8 patients were given IL-2 as an intravenous continuous infusion at a dose of 5 MU/m2/d on days 1 through 5 and days 15 through 19. Subcutaneous GM-CSF at 125 microg/d on days 1 through 21 was administered concomitantly with IL-2. The median number of IL-2 bolus doses was 23 of a scheduled 28 (85%), whereas with the continuous infusion, 93% of planned IL-2 was given. All patients received 100% of GM-CSF doses. There were no complete or partial responses in this study. Of 13 patients treated in the bolus IL-2 arm, 10 had systemic progression of disease at 4 to 8 weeks, 1 developed metastasis in the brain at 4 weeks, and 2 had stable disease for 4 and 17 months. Among the 8 subjects treated with continuous infusion IL-2, 3 progressed with brain lesions at 3 to 8 weeks and 5 had stable disease at 6+, 7, 8+, 15+, and 17+ months. The median survival for the whole group was 10 months, with a range of 0.5 to 40+ months. There were no regimen-related deaths, and most of the observed toxicities were grade 1 and 2. Serious toxicities (grade 3 and 4) included anemia, atrial fibrillation, oliguria, abnormal liver function, and neurologic events like agitation or confusion. The combination of recombinant IL-2 and GM-CSF administered in the designed schedule and doses was not effective in patients with metastatic RCC and may even interfere with the therapeutic potential of moderate-dose IL-2 and increase its adverse events.

Immunotherapy for urological malignancies

PURPOSE

For decades urologists have successfully used immunotherapy in the battle against cancer. Interleukin-2 in renal cell carcinoma and bacillus Calmette-Guerin in bladder cancer are standard primary and/or adjunctive therapies for these diseases. Recent advances in our understanding of mechanisms governing immune system activation have fostered a myriad of novel immunotherapeutic approaches that show great promise in vivo but have had limited success in human trials to date. This review highlights current immunotherapy strategies that may prove to be successful treatments for urological cancers.

MATERIALS AND METHODS

We performed a MEDLINE literature search for articles relating to immunotherapy in bladder, prostate and renal cell carcinoma in animals and humans. We included the most promising developments in this review.

RESULTS

In addition to combining existing therapies to improve their efficacy, novel approaches that attempt to exploit the immune system ability to identify, target and eradicate malignancies are now being developed. These therapies include the use of antitumoral monoclonal and bi-specific antibodies, manipulation of T-lymphocyte costimulatory molecules and the administration of newly discovered cytokines as well as the development of antitumor vaccines.

CONCLUSIONS

To date the full potential of immunotherapy for the treatment of urological malignancies has not been recognized. As our knowledge of the immune system expands, so too may our ability to manipulate it to affect tumor regression. This review describes the most recent and most promising developments in immunotherapy for urological malignancies.

Immunotherapy for renal cell carcinoma

Renal cell carcinoma (RCC) is the most prevalent malignancy within the kidney and the incidence is rising. Due to improved radiological evaluation over 50% of the renal cancers are found incidentally. Despite the fact that these incidentalomas are often confined to the kidney, around 50% of all patients diagnosed with kidney cancer will develop systemic disease. Metastatic RCC has a poor prognosis. Traditional treatment modalities like chemo- and radiotherapy show overall response percentages of 2-6%. In view of the observed spontaneous remissions of advanced renal cancer, immune mechanisms have been suggested to play a role in the natural disease course of RCC. At present, several non-specific cytokine regimens are used in the treatment of mRCC, e.g. interleukin-2 and interferon-alpha, in combination or as monotherapy or in combination with substances like 13-cis-retinoic acid and/or 5-fluorouracil. Collective data of trials evaluating cytokine-based therapies for mRCC show an overall response rate of approximately 15%, with 5% of the patients showing complete responses. More importantly, cytokine treatment clearly translates into a significant survival benefit in a subset of patients. Nevertheless, the toxicity profile of these cytokine regimens is significant. With the enhanced knowledge of tumor-immunology, the identification of immunogenic tumor proteins, and antibodies recognizing tumor-associated antigens, new treatment strategies with increased specificity and fewer side effects are of interest. Here we review the different immunotherapeutical modalities currently used as well as new approaches for the treatment of advanced RCC.

Site-specific PEGylation of a lysine-deficient TNF-alpha with full bioactivity

Addition of polyethylene glycol to protein (PEGylation) to improve stability and other characteristics is mostly nonspecific and may occur at all lysine residues, some of which may be within or near an active site. Resultant PEGylated proteins are heterogeneous and can show markedly lower bioactivity. We attempted to develop a strategy for site-specific mono-PEGylation using tumor necrosis factor-alpha (TNF-alpha). We prepared phage libraries expressing TNF-alpha mutants in which all the lysine residues were replaced with other amino acids. A fully bioactive lysine-deficient mutant TNF-alpha (mTNF-alpha-Lys(-)) was isolated by panning against TNF-alpha-neutralizing antibody despite reports that some lysine residues were essential for its bioactivity. mTNF-alpha-Lys(-) was site-specifically mono-PEGylated at its N terminus. This mono-PEGylated mTNF-alpha-Lys(-), with superior molecular uniformity, showed higher bioactivity in vitro and greater antitumor therapeutic potency than randomly mono-PEGylated wild-type TNF-alpha. These results suggest the usefulness of the phage display system for creating functional mutant proteins and of our site-specific PEGylation approach.

Novel therapies for renal cell carcinoma--an update

This article reviews the recent progress in the search for new treatments for renal cell cancer (RCC), based on a variety of preclinical models or strategies. Some recent clinical trials addressing migrating treatments from other cancers onto RCC and novel agents are discussed, as well as the molecular targets for some of the novel agents. Drugs oriented to histologically definable RCC features, such as the G250 antigen, and the receptor tyrosine kinases, such as epidermal growth factor receptor, are reviewed. Drugs aimed at antiangiogenesis and perturbing features of the cell cycle are also mentioned, including preclinical and empirical experience. Molecular techniques in the study of von Hippel Lindau-related pathways and mRNA expression analyses are cited. Within the immune model of therapy, progress in the application of immune-related drugs including older cytokines (IL-2, IFN-alpha) and of newer cytokine-variant and other cytokines are discussed. Finally, cell-based therapies such as lymphocyte infusions, tumour-cell vaccines, dendritic cell vaccines and allogeneic mini-transplant are outlined. Although high percentage improvements in outcomes for metastatic RCC are not yet realised, the many fronts for scientific and clinical advances form some basis for optimism in the coming years.

Immunotherapy of metastatic renal cell cancer

BACKGROUND

The management of metastatic renal cancer remains a therapeutic challenge. Conventional cytotoxic chemotherapy is rarely effective, and the most promising approaches appear to lie in the field of immunotherapy.

METHODS

The authors review the literature regarding current and investigational immunotherapy approaches to the management of metastatic renal cancer.

RESULTS

The mechanism of action, methods of delivery, efficacy, and side effect profile of the cytokines IL-2 and interferon alfa are discussed. The role of investigational approaches such as tumor vaccines, antibody-based therapy, lymphocyte infusions, and bone marrow transplantation is addressed. The rationale for nephrectomy as an adjunctive procedure to immunotherapy is also discussed.

CONCLUSIONS

Ongoing laboratory investigation of the cause of the immune deficit in patients with metastatic renal cell cancer will result in the development of novel therapies to enhance tumor cell recognition as well as host antitumor response. Translation of laboratory findings into the clinic will be facilitated by the presence of an already well-developed infrastructure for the performance of clinical trials for patients with this difficult diagnosis.

Effect of coadministration of M-CSF and IFN-alpha on NK1.1+ cells in mice

The purpose of this study was to evaluate the effect of coadministration of macrophage colony-stimulating factor (M-CSF) and interferon-alpha (IFN-alpha) on NK1.1(+) cells in mice. Administration of M-CSF, but not IFN-alpha, increased the number of NK1.1(+) cells and CD11b(+) cells in spleen and blood. Coadministration of the two agents induced a greater increase in NK1.1(+) cells than did administration of M-CSF alone. Administration of M-CSF or IFN-alpha augmented the clearance activity of Yac-1 cells in lung, and coadministration of these agents further augmented this effect. The combination of M-CSF and IFN-alpha effectively reduced the formation of tumor nodules in lung and liver in an experimental metastasis model using B16 melanoma. The combination of M-CSF and IFN-alpha induced the increase and activation of NK1.1(+) cells more than either agent alone. These effects may contribute to the antimetastatic reaction by NK1.1(+) cells in vivo.