Outpatient treatment with subcutaneous histamine dihydrochloride in combination with interleukin-2 and interferon-alpha in patients with metastatic renal cell carcinoma: results of an open single-armed multicentre phase II study

Histamine in cancer immunology and immunotherapy. Current status and new perspectives

Cancer is the second leading cause of death globally and its incidence and mortality are rapidly increasing worldwide. The dynamic interaction of immune cells and tumor cells determines the clinical outcome of cancer. Immunotherapy comes to the forefront of cancer treatments, resulting in impressive and durable responses but only in a fraction of patients. Thus, understanding the characteristics and profiles of immune cells in the tumor microenvironment (TME) is a necessary step to move forward in the design of new immunomodulatory strategies that can boost the immune system to fight cancer. Histamine produces a complex and fine-tuned regulation of the phenotype and functions of the different immune cells, participating in multiple regulatory responses of the innate and adaptive immunity. Considering the important actions of histamine-producing immune cells in the TME, in this review we first address the most important immunomodulatory roles of histamine and histamine receptors in the context of cancer development and progression. In addition, this review highlights the current progress and foundational developments in the field of cancer immunotherapy in combination with histamine and pharmacological compounds targeting histamine receptors.

Addition of histamine to subcutaneously injected Plasmodium berghei sporozoites increases the parasite liver load and could facilitate whole-parasite vaccination

BACKGROUND

Whole-parasite immunization remains the benchmark in malaria vaccine development. A major bottleneck in the translation of whole-parasite immunization towards routine vaccination is the mode of administration, since high degrees of protection are currently only achieved by intravenous, and not by intradermal or subcutaneous injection of viable parasites. It is known that only a small proportion of subcutaneously administered parasites reach the subsequent liver stage and low parasite liver load was shown to be associated with low protective efficacy. The objective of this analysis was to evaluate whether the liver load following subcutaneous parasite injection could be augmented by co-administration of pro-inflammatory or anti-coagulatory drugs.

METHODS

In the C57BL/6 Plasmodium berghei ANKA model, the clinical outcome (time to patent blood stage infection and survival) and relative parasite liver load was assessed in mice infected by subcutaneous or intramuscular sporozoite (SPZ) administration in the presence or absence of histamine and heparin supplementation in comparison to intravenously administered SPZ. In addition, a vaccination experiment was carried out to assess the protective efficacy of an improved, histamine-supplemented subcutaneous immunization regimen.

RESULTS

The parasite liver load following subcutaneous SPZ administration can be significantly increased by co-administration of histamine and heparin. A dose-dependent relation between parasite liver load and histamine dosage was observed. However, despite a relatively high parasite liver load, the protective efficacy of histamine-supplemented subcutaneous immunization remains inferior as compared to intravenous SPZ administration.

CONCLUSIONS

Histamine supplementation might facilitate the future development of a non-intravenous whole-parasite vaccine. Further investigations are needed to reveal the effect of histamine supplementation and subcutaneous SPZ administration on the acquisition of protective immunity.

Interferon-α-based immunotherapy in metastatic renal cell carcinoma patients with the primary tumor in situ

OBJECTIVE

We reviewed the outcomes of metastatic renal cell carcinoma patients with the primary tumor in situ who initially underwent interferon-α-based immunotherapy to evaluate the effect of this therapy on metastatic sites as well as primary kidney tumor and survival.

METHODS

Thirty-one patients, for whom upfront cytoreductive nephrectomy was considered to be inappropriate because of poor performance status and far-advanced disease, were the subject of the present study. Tumor response and reduction in the size of metastatic sites and primary kidney tumor were assessed. Overall survival distributions were estimated using the Kaplan-Meier method with the significance determined using the log-rank test.

RESULTS

Partial response was observed in 11 patients, yielding an overall response rate of 35%. Seventeen patients had regression or stabilization of metastatic sites, while progression of metastatic sites was observed in the remaining 14 patients. Regarding the maximum response of primary kidney tumor, a reduction in kidney primary tumor size was observed in 42% of the patients and the mean reduction rate in these patients was 18.2% (range: 3-36%). Furthermore, the reduction in the size of metastatic sites was significantly associated with that in the size of primary kidney tumor (R(2)= 0.432, P< 0.0001). The median survival for the 31 patients was 17 months. The median survival was 42 months in patients with regression or stabilization of metastatic sites and 7 months in those without (P< 0.001).

CONCLUSIONS

The present study suggests that metastatic sites as well as primary kidney tumor respond to interferon-α-based immunotherapy in metastatic renal cell carcinoma patients with primary tumor in situ.

Results of a multicenter randomized study to evaluate the safety and efficacy of combined immunotherapy with interleukin-2, interferon-{alpha}2b and histamine dihydrochloride versus dacarbazine in patients with stage IV melanoma

BACKGROUND

The safety and efficacy of immunotherapy with histamine dihydrochloride (HDC), interleukin-2 (IL-2) and interferon-alpha2b (IFN) compared with dacarbazine (DTIC) in adult patients with stage IV melanoma was evaluated.

PATIENTS AND METHODS

Two hundred and forty-one patients were randomized to either receive repeated 4-week cycles of IFN [3 MIU, s.c., once daily for 7 days], IL-2 (2.4 MIU/m(2), s.c., twice a day for 5 days) and HDC (1 mg, s.c., twice a day for 5 days) or DTIC 850 mg/m(2) i.v. every 3 weeks. The primary endpoint was overall survival.

RESULTS

Median survival was longer for patients receiving HDC/IL-2/IFN (271 days) than for patients receiving DTIC (231 days), but this did not achieve statistical significance. Four patients receiving HDC/IL-2/IFN and nine receiving DTIC experienced at least one grade 4 adverse event. Striking differences in overall survival were observed between countries participating in the study.

CONCLUSION

Treatment with HDC/IL-2/IFN was safely administered on an outpatient basis, but this immunotherapeutic regimen did not improve upon the response rate and overall survival seen with DTIC.

Impact of immune parameters on long-term survival in metastatic renal cell carcinoma

PURPOSE

The purpose of this study was to evaluate the impact of immunologic prognostic factors in combination with established clinical prognostic factors in patients with metastatic renal cell carcinoma (mRCC).

PATIENTS AND METHODS

A total of 120 consecutive patients with mRCC received interleukin-2 (IL-2) -based immunotherapy. Baseline tumor biopsies were available from 85 of these patients. Potential prognostic factors were analyzed by univariate and multivariate analyses.

RESULTS

Multivariate analysis (N = 120) identified high lactate dehydrogenase, lymph node metastases, low hemoglobin, low Karnofsky performance status, and bone metastases as independent poor prognostic clinical factors. The impact of these clinical factors has been demonstrated by others. Multivariate analysis (n = 85) also identified a high blood neutrophil count (> 6.0 x 10(9)/L; hazard ratio, 2.0; P = .015), the presence of intratumoral neutrophils (> 0 cells/mm2 tumor tissue; hazard ratio, 2.3; P = .001), and low intratumoral CD57+ natural killer cell count (< 50 cells/mm2 tumor tissue; hazard ratio, 2.1; P = .01) as independent poor prognostic immunologic factors. These three independent immunologic parameters had significant discriminatory power as supplemental risk factors in prognostic models based on the clinical risk factors, identifying subgroups within the favorable clinical group with estimated 5-year survival rates of 60%, 25%, and 0%, respectively. These findings were apparent in both our own prognostic model and in an extended Memorial Sloan-Kettering Cancer Center (New York, NY) prognostic model.

CONCLUSION

This study points on five clinical and three supplemental immunologic independent prognostic factors of survival in patients with mRCC receiving IL-2.

Monocytes and neutrophils as 'bad guys' for the outcome of interleukin-2 with and without histamine in metastatic renal cell carcinoma--results from a randomised phase II trial

Histamine (HDC) inhibits formation and release of phagocyte-derived reactive oxygen species, and thereby protects natural killer (NK) and T cells against oxidative damage. Thus, the addition of histamine may potentially improve the efficacy of interleukin-2 (IL-2). We have explored this potential mechanism clinically in two randomised phase II trials in metastatic renal cell carcinoma (mRCC). In parallel with the clinical trial in Denmark (n=63), we obtained serial blood samples and tumour biopsies searching for a potential histamine effect in situ. At baseline and on-treatment weeks 3 and 8, we monitored the ‘good guys’ (i.e. NK and T cells) and ‘bad guys’ (i.e. monocytes/macrophages and neutrophils) simultaneously in blood (n=59) and tumour tissue (n=44). Patients with high number of monocytes and neutrophils in peripheral blood had very poor survival, with apparently no benefit from either IL-2 alone or IL-2/HDC treatment. Blood monocytes (r=−0.36, P=0.01) and neutrophils (r=−0.46, P=0.001) were negatively correlated with cytotoxicity, whereas blood NK cells were positively correlated with cytotoxicity (r=0.39, P=0.002). Treatment with IL-2 alone resulted in a significantly higher number of circulating monocytes (P=0.037) and intratumoral macrophages (P=0.005) compared with baseline. In contrast, IL-2/HDC resulted in an unchanged number of circulating monocytes and intratumoral macrophages, and in addition, a significantly increased number of intratumoral CD56⁺ NK cells (P=0.008) and CD8⁺ T cells (P=0.019) compared with baseline. The study provides evidence that circulating monocytes and neutrophils are powerful negative prognostic factors for IL-2-based immunotherapy and establishes a biological rationale for the potential use of histamine in conjunction with IL-2 in mRCC.

Two randomised phase II trials of subcutaneous interleukin-2 and histamine dihydrochloride in patients with metastatic renal cell carcinoma

Histamine inhibits formation and release of phagocyte-derived reactive oxygen species, and thereby protects natural killer and T cells against oxidative damage. Thus, the addition of histamine may potentially improve the efficacy of interleukin-2 (IL-2). Two randomised phase II trials of IL-2 with or without histamine dihydrochloride (HDC) in patients with metastatic renal cell carcinoma (mRCC) were run in parallel. A total of 41 patients were included in Manchester, UK and 63 in Aarhus, Denmark. The self-administered, outpatient regimen included IL-2 as a fixed dose, 18 MIU s.c. once daily, 5 days per week for 3 weeks followed by 2 weeks rest. Histamine dihydrochloride was added twice daily, 1.0 mg s.c., concomitantly with IL-2. A maximum of four cycles were given. The Danish study showed a statistically significant 1-year survival benefit (76 vs 47%, P=0.03), a trend towards benefit in both median survival (18.3 vs 11.4 months, P=0.07), time to PD (4.5 vs 2.2 months, P=0.13) and clinical benefit (CR+PR+SD) (58 vs 37%, P=0.10) in favour of IL-2/HDC, whereas the UK study was negative for all end points. Only three patients had grade 4 toxicity; however, two were fatal. A randomised phase III trial is warranted to clarify the potential role of adding histamine to IL-2 in mRCC.

Fas ligand expression in metastatic renal cell carcinoma during interleukin-2 based immunotherapy: no in vivo effect of Fas ligand tumor counterattack

PURPOSE

It has been hypothesized that tumor cells expressing Fas ligand (FasL) might be able to counterattack and neutralize tumor-infiltrating lymphocytes. We assessed the effect of FasL tumor counterattack on the clinical outcome of interleukin-2 (IL-2)-based immunotherapy in metastatic renal cell carcinoma.

EXPERIMENTAL DESIGN

Tumor core needle biopsies were obtained before IL-2-based immunotherapy in 86 patients and repeated within the first cycle in 57 patients. Tumor cells expressing FasL and intratumoral lymphocyte subsets expressing CD4, CD8, CD56, and CD57 were analyzed by immunohistochemistry.

RESULTS

At baseline, negative FasL staining in tumor cells was seen in 10 of 86 (12%) biopsies, whereas intense FasL staining was seen (a) in fewer than 10% of tumor cells in 26 (30%) biopsies; (b) in 11 to 50% of tumor cells in 25 (29%) biopsies; (c) in 51 to 90% of tumor cells in 18 (21%) biopsies; and (d) in >90% of tumor cells in 7 (8%) biopsies. On treatment, tumor FasL expression did not change from baseline levels. Moreover, tumor FasL expression was not correlated with objective response or survival whereas the absolute number of CD4(+), CD8(+), CD56(+), and CD57(+) cells per mm(2) tumor tissue at baseline was significantly higher in responding patients compared with nonresponding patients (P = 0.01, P = 0.008, P = 0.015, and P < 0.001, respectively). During the first course of immunotherapy, the absolute number of CD4(+), CD8(+), and CD57(+) cells per mm(2) tumor tissue was significantly higher in responding patients compared with nonresponding patients (P = 0.034, P < 0.001, and P < 0.001, respectively). However, no correlation was observed between the number of intratumoral lymphocytes and tumor FasL expression level.

CONCLUSION

These observations do not support the hypothesis that FasL tumor "counterattack" has an effect on the clinical outcome in metastatic renal cell carcinoma during IL-2-based immunotherapy.

Histamine improves survival and protects against interleukin-2-induced pulmonary vascular leak syndrome in mice

The therapeutic efficacy in the treatment of metastatic cancer with high doses of interleukin-2 (IL-2) has been limited by the onset of vascular leak syndrome (VLS) and related toxicities. VLS is characterized by an increase in vascular permeability and severe hypotension resulting in interstitial edema and organ failure. This study explores the protective effects of histamine dihydrochloride (HDC) against IL-2-induced toxicities in mice. Treatment with HDC administered before or after IL-2 (1.25 x 10(6) IU, BID) was shown to protect mice from VLS-related toxicities and mortality in a dose-dependent manner. Survival rates when HDC was added were 56, 75 and 81% at doses of 0.47, 4.7 and 47.0 mg/kg, respectively, compared to 42% survival with IL-2 alone. HDC protected against IL-2-induced macroscopic pulmonary lesions, reduced edema (up to 62% reduction in lung wet/dry weight ratio) and reduced capillary leakage into the lungs as measured by a reduction in Evans Blue dye content. In addition, the systemic effect on serum cytokine levels showed that HDC only moderately lowered IL-2 induced IFN-gamma, IL-6, IL-10, IL-18 and TNF-alpha. Serum levels of IL-1beta, IL-4 and IL-12 were not measurably induced by IL-2 treatment. HDC modulates many cellular functions including regulating cytokines and blocking immune-suppression caused by reactive oxygen species (ROS) generated by the NADPH oxidase. However, the protective effect of HDC on alleviating IL-2-induced pulmonary edema was not related to ROS inhibition. Our data indicate that HDC treatment improves survival and protects against IL-2 induced VLS independent of ROS regulation in mice.

In vivo assessment of the antiproliferative properties of interferon-alpha during immunotherapy: Ki-67 (MIB-1) in patients with metastatic renal cell carcinoma

The aim of the present study was to investigate the in vivo antiproliferative effect of interferon alpha (IFN-α) in patients with metastatic renal cell carcinoma (mRCC). Core needle biopsies of metastatic and/or the primary kidney cancer were obtained before interleukin-2 (IL-2)- and IFN-α-based immunotherapy in 34 patients and repeated after 5 weeks in 25 patients. Tumour proliferation was assessed by use of the anti-Ki-67 antibody MIB-1 and evaluated in multiple, random systematic sampled fields of vision. Ki-67 labelling index (LI) at baseline was median 13.6% (range 1.2–85.0) and median 10.6% (range 1.3–48.6%) at week 5 with a median overall decline of 15.2% (range −95 to +258%) from baseline to week 5. There was no difference between responding and nonresponding patients. Ki-67 LI at week 5 was significantly correlated to survival. Thus, median survival of patients with Ki-67 LI ⩽10.6% at week 5 was 25.1 months compared to 11.5 months for patients with Ki-67 LI >10.6% (P=0.016). Baseline or change in Ki-67 LI did not correlate to survival. These data suggest that IFN-α in vivo has only modest effect on tumour proliferation in patients with mRCC. Tumour Ki-67 (MIB-1) reactivity after 1 month of immunotherapy appears to be a significant predictor of patient survival.

A phase II study of outpatient subcutaneous histamine dihydrochloride, interleukin-2 and interferon-alpha in patients with metastatic melanoma

BACKGROUND

Experimental data had suggested a synergistic effect of histamine with interleukin-2 (IL-2) and interferon-alpha (IFN-alpha).

PATIENTS AND METHODS

Forty-one patients with metastatic melanoma received IL-2 9 MU subcutaneously (s.c.) twice daily on days 4-8 and 25-29, and once daily on days 11-15 and 32-36. IFN-alpha-2b was given as 5 MU s.c. on days 1-3 and then daily to day 43. Histamine 1 mg s.c. was administered twice daily, following IL-2 and IFN injections starting on day 4. Efficacy and toxicity were compared with those of 42 patients included on exactly the same criteria and receiving the same regimen but without histamine.

RESULTS

Two patients achieved a partial response (PR) for an objective response rate of 5% [95% confidence interval (CI) 1% to 17%]. Median overall survival was 7.8 months (95% CI 6.4-9.1). In the control group, two complete responses and one PR were achieved. Median overall survival was 7.1 months (95% CI 5.4-8.9).

CONCLUSIONS

This IL-2 and IFN regimen was well tolerated on an outpatient basis. However, the applied regimen cannot be recommended because of the low clinical efficacy. Histamine did not add efficacy or toxicity in combination with this moderate-dose schedule of IL-2 and IFN.

A multicentre, randomized study to evaluate the safety and efficacy of histamine dihydrochloride and interferon-alpha-2b for the treatment of chronic hepatitis C

Interferon- (IFN-)alpha is currently the standard of care treatment for patients with chronic hepatitis C virus (HCV) infection. A significant part of the benefit of IFN-alpha in chronic hepatitis C is believed to be related to the activation of lymphocytes such as T cells and natural killer (NK) cells, which participate in the elimination of infected cells. Histamine dihydrochloride (HDC) has been shown to potentiate the IFN-alpha-induced activation of T cells and NK cells by a mechanism that involves the protection of these lymphocytes against oxygen radical-induced functional inhibition and apoptosis. This study was designed to examine the efficacy and safety of HDC in combination with IFN-alpha-2b in treatment-naïve patients with chronic HCV infection. All patients received IFN-alpha-2b, 3 MIU, three times weekly via subcutaneous injection, and were randomized to one of four HDC regimens (1 mg of either: once a day, three times a week; once a day, five times a week; twice a day, three times a week or; twice a day, five times a week). The doses of HDC in combination with IFN-alpha-2b resulted in sustained viral response rates ranging from 31% to 38%. Sustained biochemical response rates ranged from 28% to 41% across the four treatment groups. Patients infected with HCV genotype 1, and those with high baseline viral levels, which are characteristics associated with poor prognosis, had sustained virologic response rates ranging from 18% to 42% and 15% to 39%, respectively. Combination treatment was generally well tolerated. We propose that the potential benefit of HDC + IFN therapy for chronic HCV infection should be the focus of further investigation.

Intratumoural and peripheral blood lymphocyte subsets in patients with metastatic renal cell carcinoma undergoing interleukin-2 based immunotherapy: association to objective response and survival

The aim of the present study was to analyse lymphocyte subsets in consecutive peripheral blood samples and consecutive tumour tissue core needle biopsies performed before and during interleukin-2 based immunotherapy, and to correlate the findings with objective response and survival. Twenty-six patients with metastatic renal cell carcinoma were treated with low dose s.c. interleukin-2, interferon-alpha and histamine. A total of 250 blood samples and 62 core needle biopsies from 23 and 19 of these patients, respectively, were analysed. After 2 weeks of treatment, a significant positive correlation between absolute number of peripheral blood lymphocytes (P=0.028), CD3 (P=0.017), CD57 (P=0.041) and objective response was demonstrated. There was no correlation between any peripheral blood leukocyte subsets and survival. Cytotoxicity of peripheral blood mononuclear cells was not correlated to objective response or survival. Within the tumour tissue at baseline, a significant positive correlation between CD4 (P=0.027), CD8 (P=0.028), CD57 (P=0.007) and objective response was demonstrated. After one month of immunotherapy, a significant positive correlation between intratumoral CD3 (P=0.026), CD8 (P=0.015), CD57 (P=0.009) and objective response was demonstrated. A significant positive correlation between intratumoral baseline CD4 (P=0.047), baseline CD57 (P=0.035), CD3 at one month (P=0.049) and survival was demonstrated. These data provide novel in vivo evidence of the possible contribution of lymphocyte subsets in the tumour reduction in responding patients during interleukin-2 based immunotherapy. Confirmation of the results requires further studies including a larger number of patients.

Pharmacokinetics of histamine dihydrochloride in healthy volunteers and cancer patients: implications for combined immunotherapy with interleukin-2

Recent clinical trials in melanoma and leukemia have demonstrated potential for increased survival time and improved remission when histamine dihydrochloride is added to cytokine monotherapy. In the present study, the pharmacokinetics of subcutaneous histamine (1 mg) in 21 healthy subjects and 12 melanoma patients was determined via model-dependent methods. Drug-drug interactions with subcutaneous interleukin-2 (1.1 mg) were evaluated in a combined cohort of patients with melanoma (n = 8) or renal cell carcinoma (n = 4). Histamine dihydrochloride administered over 10 minutes in healthy subjects peaked at 18 minutes (Cmax 38 nmol/L), attained a distribution volume of 59 L, and was eliminated at 6%/min. The results were similar in a 20-minute infusion in melanoma patients. No gender effects were observed (p > 0.05). Interleukin-2 injected either 10 minutes prior to or 10 minutes following histamine dihydrochloride had no effect on histamine kinetics. Histamine dihydrochloride administered 10 minutes prior to injection of interleukin-2 also had no effect on interleukin-2 kinetics. Maximal concentration of interleukin-2 (2,442 pg/ml) occurred at 2.5 hours with an elimination half-life of 1.7 hours, area under the curve (AUC) of 15,746 pg x h/ml, and volume of distribution and plasma clearance of 194 L and 74 L/h, respectively. However, interleukin-2 Cmax (1,758 pg/ml) and AUC (12,448 pg x h/ml) were reduced when histamine dihydrochloride was infused 10 minutes following interleukin-2, likely due to the pharmacodynamic effects of histamine, including increased heart rate and reduced blood pressure. It is concluded that histamine dihydrochloride and interleukin-2 can be safely coadministered with minimal interaction.

Therapeutic options in the management of renal cell carcinoma

Approximately 31,000 new cases of renal cell carcinoma (RCC) are diagnosed in the United States each year and 30% to 40% of these will eventually become metastatic disease. The primary tumor often grows to considerable size before symptoms are apparent, which could explain the high rate of metastatic RCC (mRCC). The median survival of mRCC after diagnosis is 8 to 12 months and the 5-year survival is less than ideal. Traditionally, surgery has been the treatment of choice for mRCC. Chemotherapeutic agents tested so far have been disappointing, perhaps because of a high expression of the multidrug resistance gene or the high content of glutathione in RCC cells. However, the spontaneous regression of mRCC in some cases suggests that these tumor cells are responsive to immunologic mechanisms. Initial interest has focused on two cytokines, interferon-alpha (IFN-alpha) and interleukin-2 (IL-2), with response rates ranging from 15% to 20%. Both IL-2 and IFN-alpha are pleiotropic compounds with specific effects on many leukocyte subsets, in addition to directly affecting tumor proliferation, angiogenesis, and antigen expression. The mechanisms by which these immunoenhancing cytokines exert antitumor effects are still unknown. However, many agree that activation of T cells and natural killer cells is a pivotal part of the antitumor efficacy. For example, some investigators have found that pretreatment levels of natural killer cells and T cells predict a response to IL-2 and IFN-alpha in mRCC. Others report a relationship between activation of peripheral blood lymphocytes and response to cytokine therapy. Expansion of activated T cells in blood during treatment with these two cytokines seems to relate to clinical efficacy in patients with RCC.

Histamine in cancer immunotherapy: a preclinical background

Natural killer (NK) cells and T cells are the primary targets of interleukin-2 (IL-2) and other cytokines used in cancer immunotherapy. However, these tumoricidal lymphocytes are frequently dysfunctional or apoptotic when residing within melanomas and other solid cancers. This phenomenon--tumor-induced immunosuppression--is poorly understood and conceivably limits the efficiency of strategies aiming at activating lymphocyte-mediated antitumor immunity. Recent studies imply that reactive oxygen species (oxygen radicals), produced by tumor-infiltrating monocyte/macrophages, may contribute to the state of lymphocyte inhibition in neoplastic tissue. Histamine, acting via H2-type histamine receptors on monocyte/macrophages, suppresses the activity of a key enzyme in oxygen radical formation, the NADPH oxidase. By this mechanism, histamine protects NK cells and T cells against oxygen radical-induced dysfunction and apoptosis, and also maintains their activation by IL-2 and other lymphocyte activators. In this review, these properties of histamine are discussed in relation to the current use of histamine as an adjunct to IL-2 in metastatic melanoma and other malignant diseases.