Treatment of transitional cell carcinoma of the bladder with intravesical interleukin-2: a pilot study

The past, present, and future of immunotherapy for bladder tumors

Bladder cancer is a prominent cancer worldwide with a relatively low survival rate for patients with increased stage and metastasis. Current treatments are based on surgical removal, bacillus Calmette-Guerin (BCG) Immunotherapy, and platinum-based chemotherapy. However, treatment resistance due to genetic instability of bladder tumors, as well as intolerance to treatment adverse effects leads to the necessity to further treatment options. New advancements in immunotherapy are on the rise for treatment of various cancers and specifically has shown promise in the treatment of bladder cancer. This review summarizes these new advancements in treatment options involving cytokines and cytokine blockade. Such a study might be helpful for urologists to manage patients with bladder cancer more effectively.

The Impact of a New Interleukin-2-Based Immunotherapy Candidate on Urothelial Cells to Support Use for Intravesical Drug Delivery

(1) Background: The intravesical instillation of interleukin-2 (IL-2) has been shown to be very well tolerated and promising in patients with bladder malignancies. This study aims to confirm the use of a new IL-2 containing immunotherapy candidate as safe for intravesical application. IL-2, produced in mammalian cells, is glycosylated, because of its unique solubility and stability optimized for intravesical use. (2) Materials and Methods: Urothelial cells and fibroblasts were generated out of porcine bladder and cultured until they reached second passage. Afterwards, they were cultivated in renal epithelial medium (REM) and Dulbecco’s modified Eagles medium (DMEM) with the IL-2 candidate (IMS-Research) and three more types of human interleukin-2 immunotherapy products (IMS-Pure, Natural IL-2, Aldesleukin) in four different concentrations (100, 250, 500, 1000 IU/mL). Cell proliferation was analyzed by water soluble tetrazolium (WST) proliferation assay after 0, 3, and 6 days for single cell culture and co-culture. (3) Results: Proliferation assays showed that all IL-2 products induced very similar cultivation results and none of the IL-2 variants had a negative impact on the proliferation of urothelial cells and fibroblast in either concentration. (4) Conclusion: Human recombinant glycosylated IL-2 as well as human non-glycosylated IL-2 have no negative influence on the tissue cell proliferation of porcine urothelial cells and fibroblasts in vitro and represent a promising and innovative potential intravesical therapy candidate for patients in high need.

Quadruple immunotherapy of Bacillus Calmette-Guérin, interferon, interleukin-2, and granulocyte-macrophage colony-stimulating factor as salvage therapy for non-muscle-invasive bladder cancer

BACKGROUND

Bacillus Calmette-Guérin (BCG) is the most effective initial intravesical therapy for high-grade non-muscle invasive bladder cancer, but many patients still fail. Combination intravesical BCG and interferon (IFN) will salvage some patients but results remain suboptimal.

OBJECTIVE

We hypothesized that further immunostimulation with intravesical interleukin-2 and subcutaneous granulocyte-macrophage colony-stimulating factor may improve response to intravesical BCG and IFN in patient with prior BCG failure(s).

METHODS

A retrospective review was performed. Patients received 6 treatments of quadruple immunotherapy (intravesical solution with one-third dose BCG, 50 million units IFN, and 22 million units interleukin-2, along with a 250-mcg subcutaneous sargramostim injection). Surveillance began 4 to 6 weeks after treatment completion. Patients received maintenance if recurrence-free. Success was defined as no recurrence (bladder or extravesical) and bladder preservation. Analysis was performed by Kaplan-Meier method (P<0.05).

RESULTS

Fifty-two patients received treatment with a median recurrence follow-up of 16.3 months and overall follow-up of 41.8 months. All patients had at least 1 prior BCG failure and 13% had 2 or more prior failures. Only 3 patients (6%) were unable to tolerate full induction. Treatment success was 55% at 1 year, and 53% at 2 years. Thirteen patients (25%) underwent cystectomy at a median time of 17.3 months with disease progression to T2 in 1 patient and T3 in 2 patients. No patients had positive surgical margins or positive lymph nodes.

CONCLUSIONS

In patients with non-muscle-invasive bladder cancer with prior BCG failure, quadruple immunotherapy demonstrated good treatment success in some patients and warrants further evaluation.

Immunotherapy for urothelial cancer: from BCG to checkpoint inhibitors and beyond

Since its introduction almost 40 years ago, intravesical BCG for non-muscle invasive bladder cancer remains one of the most successful cancer immunotherapies. However, up to 40% of patients will progress after BCG therapy and develop invasive bladder cancer. Despite its extensive clinical use, we are only beginning to understand how BCG works. Here we review preclinical and clinical data that implicate BCG-induced Th1 and cytotoxic cellular immune responses in cancer regression. We propose that future immunotherapies should aim to augment Th1 and/or cellular responses in those that fail BCG therapy. We review clinical trials of immunotherapy in bladder cancer with a focus on the promising role of checkpoint blockade inhibitors that target the programmed cell death 1/programmed death-ligand 1 (PD-L1) axis and/or cytotoxic T lymphocyte antigen 4.

Bladder Cancer Immunotherapy: BCG and Beyond

Mycobacterium bovis bacillus Calmette-Guérin (BCG) has become the predominant conservative treatment for nonmuscle invasive bladder cancer. Its mechanism of action continues to be defined but has been shown to involve a T helper type 1 (Th1) immunomodulatory response. While BCG treatment is the current standard of care, a significant proportion of patients fails or do not tolerate treatment. Therefore, many efforts have been made to identify other intravesical and immunomodulating therapeutics to use alone or in conjunction with BCG. This paper reviews the progress of basic science and clinical experience with several immunotherapeutic agents including IFN-α, IL-2, IL-12, and IL-10.

Local therapy of cancer with free IL-2

This is a position paper about the therapeutic effects of locally applied free IL-2 in the treatment of cancer. Local therapy: IL-2 therapy of cancer was originally introduced as a systemic therapy. This therapy led to about 20% objective responses. Systemic therapy however was very toxic due to the vascular leakage syndrome. Nevertheless, this treatment was a break-through in cancer immunotherapy and stimulated some interesting questions: Supposing that the mechanism of IL-2 treatment is both proliferation and tumoricidal activity of the tumor infiltrating cells, then locally applied IL-2 should result in a much higher local IL-2 concentration than systemic IL-2 application. Consequently a greater beneficial effect could be expected after local IL-2 application (peritumoral = juxtatumoral, intratumoral, intra-arterial, intracavitary, or intratracheal = inhalation). Free IL-2: Many groups have tried to prepare a more effective IL-2 formulation than free IL-2. Examples are slow release systems, insertion of the IL-2 gene into a tumor cell causing prolonged IL-2 release. However, logistically free IL-2 is much easier to apply; hence we concentrated in this review and in most of our experiments on the use of free IL-2. Local therapy with free IL-2 may be effective against transplanted tumors in experimental animals, and against various spontaneous carcinomas, sarcomas, and melanoma in veterinary and human cancer patients. It may induce rejection of very large, metastasized tumor loads, for instance advanced clinical tumors. The effects of even a single IL-2 application may be impressive. Not each tumor or tumor type is sensitive to local IL-2 application. For instance transplanted EL4 lymphoma or TLX9 lymphoma were not sensitive in our hands. Also the extent of sensitivity differs: In Bovine Ocular Squamous Cell Carcinoma (BOSCC) often a complete regression is obtained, whereas with the Bovine Vulval Papilloma and Carcinoma Complex (BVPCC) mainly stable disease is attained. Analysis of the results of local IL-2 therapy in 288 cases of cancer in human patients shows that there were 27% Complete Regressions (CR), 23% Partial Regressions (PR), 18% Stable Disease (SD), and 32% Progressive Disease (PD). In all tumors analyzed, local IL-2 therapy was more effective than systemic IL-2 treatment. Intratumoral IL-2 applications are more effective than peritumoral application or application at a distant site. Tumor regression induced by intratumoral IL-2 application may be a fast process (requiring about a week) in the case of a highly vascular tumor since IL-2 induces vascular leakage/edema and consequently massive tumor necrosis. The latter then stimulates an immune response. In less vascular tumors or less vascular tumor sites, regression may require 9-20 months; this regression is mainly caused by a cytotoxic leukocyte reaction. Hence the disadvantageous vascular leakage syndrome complicating systemic treatment is however advantageous in local treatment, since local edema may initiate tumor necrosis. Thus the therapeutic effect of local IL-2 treatment is not primarily based on tumor immunity, but tumor immunity seems to be useful as a secondary component of the IL-2 induced local processes. If local IL-2 is combined with surgery, radiotherapy or local chemotherapy the therapeutic effect is usually greater than with either therapy alone. Hence local free IL-2 application can be recommended as an addition to standard treatment protocols. Local treatment with free IL-2 is straightforward and can readily be applied even during surgical interventions. Local IL-2 treatment is usually without serious side effects and besides minor complaints it is generally well supported. Only small quantities of IL-2 are required. Hence the therapy is relatively cheap. A single IL-2 application of 4.5 million U IL-2 costs about 70 Euros. Thus combined local treatment may offer an alternative in those circumstances when more expensive forms of treatment are not available, for instance in resource poor countries.

Current state of immunotherapy for bladder cancer

Bacillus Calmette-Guerin (BCG) has been shown to be the most effective agent for the treatment of superficial bladder cancer since its approval by the US Food and Drug Administration for the treatment of carcinoma in situ of the bladder in 1990. Recently, augmentation of BCG immunotherapy with interferon-alpha2b and other agents is emerging as salvage therapy for those patients who fail initial treatment. This review summarizes the role of various immunotherapeutic agents in the treatment of bladder cancer, with special emphasis on the appropriate administration and schedule of BCG therapy as well as salvage with the combination of BCG with interferon-alpha2b.

Phase 1 study of the intravesical administration of recombinant human interleukin-12 in patients with recurrent superficial transitional cell carcinoma of the bladder

Superficial transitional cell carcinoma (STCC) of the bladder is usually managed with intravesical bacille Calmette-Guerin. Recombinant human interleukin-12 (rhIL-12) is a heterodimeric cytokine that induces T-cell and natural killer cell proliferation/activation and production of IFNgamma. It has demonstrated preclinical in vivo bladder antitumor activity and no systemic toxicity. This phase 1 study evaluated intravesical rhIL-12 administration in patients with STCC (Tis, Ta, or T1) who had failed at least one prior intravesical therapy or had at least two recurrences of low-grade tumors. Eligible patients had adequate hematologic, renal, and hepatic function and Karnofsky performance status at least 70%. Cohorts of three patients received 5, 20, 50, 100, and 200 microg rhIL-12 (treated n = 15). Each patient received intravesical rhIL-12 weekly for 6 weeks, with a 2-hour bladder dwell. No patient experienced moderate, severe, or life-threatening systemic toxicity. Treatment-related adverse events included dysuria, urinary frequency, urinary urgency, asthenia, pain, hematuria, bladder spasms, and chills. Specific AE incidences were not dose-related. Among 12 patients without visible pretreatment lesions, 7 remained disease-free and 5 experienced recurrence of STCC within the 4-week follow-up period. Three patients with pretreatment Tis or Ta/T1 lesions had persistent disease at posttreatment follow-up. No patients with persistent tumor manifested antitumor response to rhIL-12. Two-hour dwell urine samples and 24- to 30-hour postdose serum samples showed negligible induction of IFNgamma. In summary, intravesical rhIL-12 was well tolerated by patients with recurrent STCC but showed no clinically relevant evidence of antitumor or immunologic effects.

Role of Th1 and Th2 cytokines in BCG-induced IFN-gamma production: cytokine promotion and simulation of BCG effect

Induction of a T-helper-type 1 (Th1) immune response is indispensable for successful treatment of superficial bladder cancer with BCG. In this study possible involvement of various cytokines in BCG action as well as their potential roles in enhancing and mimicking BCG effect were explored. In immunocompetent cell cultures, IFN-gamma, a major Th1 cytokine, appears to be a late responsive cytokine to BCG stimulation. Its induction requires involvement of various endogenously produced Th1 and Th2 cytokines. Functional abolishment of any one of these cytokines (IL-2, IL-6, IL-12, IL-18, GMCSF, TNF-alpha, or IFN-alpha, except IL-10) by neutralizing antibodies leads to reduced IFN-gamma production (19-82% inhibition in mouse and 44-77% inhibition in human systems, respectively). In mice cytokines IL-2, IL-12, IL-18, and GMCSF are observed to synergize with BCG for IFN-gamma production, whereas in human cytokines IL-2, IL-12, TNF-alpha, and IFN-alpha exhibit similar synergistic effects. Rational combinations of these Th1-stimulating cytokines (IL-12 plus IL-18 in mice and IL-2 plus IL-12 in humans, respectively) dramatically up-regulate IFN-gamma production that is incomparably superior to BCG for induction of this cytokine. These results suggest that combined Th1-stimulating cytokines and combinations of BCG plus selected Th1-stimulating cytokines are rational candidates for further study in the treatment of bladder cancer patients.