Current and new strategies in immunotherapy for superficial bladder cancer

REVIEW

CURRENT AND NEW STRATEGIES IN IMMUNOTHERAPY FOR SUPERFICIAL BLADDER CANCER FRANK G. E. PERABO

A

pproximately 54,400 new cases of transitional cell carcinoma (TCC) were reported in the United States in 1999, and an estimated 12,500 deaths were attributed to it.1,2 The prevalence of TCC comprises at least a total of 400,000 cases. At initial presentation, approximately 75% of cases are superficial, have papillary morphology, and derive from the urothelium. Additionally, 70% are Stage Ta (papillary) tumors confined to the mucosa (epithelium), Stage Tis (carcinoma in situ) and 30% are Stage T1 grade 3.2 In most patients with superficial bladder cancer, the tumor can be resected; however, despite complete tumor resection, two thirds of patients will develop tumor recurrence within 5 years. By 15 years, 88% of patients will have developed recurrence.3 In selected cases, the risk of progression to a muscleinvasive tumor is as much as 50% to 80%.4 As many as 20% of patients with diffuse Tis and as many as 10% of patients with focal Tis are found to have evidence of muscle invasion or occult regional metastases, respectively, on final pathologic examination when ultimately treated with radical cystectomy.5 INDICATIONS FOR INTRAVESICAL THERAPY Tumor recurrence and potential progression provide reasons to institute prophylactic therapy. Therapeutic agents can be instilled into the bladder directly by catheter, thereby avoiding the morbidity of systemic administration. The suspected biologic behavior of a specific patient’s tumor remains an important determinant factor in the decision to use intravesical therapy. In the absence of risk factors for progression, intravesical therapy is not required for grade 1, Ta lesions, because these have a progression rate of only 2% to 4%.6 However, mulFrom the Department of Urology, University Hospital, Bonn, Germany Reprint requests: Frank Perabo, M.D., P.O. Box 1906, Starnberg D 82309, Germany Submitted: January 30, 2004, accepted (with revisions): April 19, 2004 © 2004 ELSEVIER INC. ALL RIGHTS RESERVED

AND

STEFAN C. MU¨LLER

tifocal Ta disease, irrespective of grade, is also associated with an increased risk of tumor recurrence and progression and constitutes an indication for adjuvant intravesical therapy. The presence of even small foci of Tis should be considered a definite indication for intravesical therapy. Other indications for intravesical therapy include low-grade Ta disease recurring within 2 years, persistent positive urine cytology localized to the bladder, and severe atypia. The most common immunotherapeutic agent used to date is bacille Calmette-Gue´rin (BCG), an attenuated strain of Mycobacterium bovis, with proven efficacy both therapeutically and prophylactically. Although BCG has been studied intensely, and its dosing, scheduling, and administration have been optimized for years, it is not free of side effects, which can restrict the quality of life considerably. Furthermore, limitations in its efficacy have been found (eg, in the case of Tis and refractory tumors). Therefore, the search for new and effective immunotherapeutic agents for the management of superficial TCC continues. The goal of this review was to highlight the trends and approaches that have been undertaken in the search for new immunotherapeutic agents and to assess their future relevance in the treatment of superficial bladder cancer. IMMUNOLOGIC AGENTS INTERFERON Interferons (IFNs) are host-produced glycoproteins that act to mediate immune responses through antiviral, antiproliferative, and immunoregulatory activities. Because IFN is clearly one of the end products of successful BCG treatment of superficial TCC, it would seem logical that direct instillation of IFN into the bladder might be used for treatment. Various subtypes of IFN have, in fact, been used, unfortunately with only limited effects. In various studies, the efficacy of IFN was judged optimistically by the investigators; however, most of the conducted studies were of poor design and the results hardly comparable. The apUROLOGY 64: 409 – 421, 2004 • 0090-4295/04/$30.00 doi:10.1016/j.urology.2004.04.026 409

TABLE I. Compilation of clinical studies with interferons (studies with incomplete data excluded) Clinical Phase

Patients

Response

Phase II

TUR vs. TUR ⫹ adjuvant 0.7 mg/wk IFN-␥ for 8 weeks

54 patients (group 1, 28, group 2, 26), only recurrent Ta G2, T1, and Tis; Ta G1 was excluded

Phase II

TUR vs. TUR ⫹ 50 mU IFN␣2b vs. TUR ⫹ 100 mg epirubicin immediately after TUR

200 patients primary Ta– T1, G1–G3 randomized into 3 groups

Phase I–II

60 mg BCG (Danish 1331) combined with 5 mU/wk IFN-␣2b for 8 wk, fortnightly for 8 wk, monthly for 8 wks, followed by maintenance dose at end of 9, 12, 18, and 24 mo IFN-␣2b (30, 50, and 80 mU) once weekly for 12 wk vs. MM-C (40 mg) once weekly for 8 wk

37 patients, Ta and T1

Mean follow-up of 12.1 mo; tumor recurrence detected in 24 controls (86%) and 16 (62%) of IFN group (P ⫽ 0.043); comparison of diseasefree survival between groups showed continuous protective effect to those who received IFN (P ⫽ 0.0237) At median follow-up of 72 mo, sustained effect of single epirubicin instillation compared with other treatments observed; only 46% of patients in group 3 experienced recurrence in contrast to 73% and 68% in group 1 and 2, respectively (P ⫽ 0.002); at 72 mo, diseasefree survival rate 24%, 31%, and 51% in groups 1–3, respectively (P ⫽ 0.002); multivariate model revealed ⬎2-fold relative risk of recurrence in group 1 vs. group 3 (P ⬍0.001) Average follow-up 60 mo; at end of 1 yr, 84% had no tumor recurrence; which dropped to 36% at end of 5 yr; 20% had disease progression within 5-yr interval

Phase II

Phase I–II

Phase II

Dose/Schedule

1/3 dose (27 mg) BCG ⫹ 50 mU IFN-␣2b for 6–8 weekly treatments 81 mg BCG on wk 1, 3, 5, and 7 and IFN-␣2b 100 mU on wk 2, 4, 6, and 8.

115 patients, Ta–T1, G1–G2

IFN at doses of 30, 50, and 80 mU gave response rate at 13 weeks of 19%, 33%, and 41%, respectively; although responses better for 50 and 80 mU than 30 mU, differences not statistically significant; all 3 IFN groups had lower response rates than MM-C group (72%)

40 patients in whom previous BCG failed; Ta, T1, Tis, G1–G3 37 patients Ta–T1 G1– G3, Tis

At median follow-up of 30 mo, 63% and 53% of patients were disease free at 12 and 24 months, respectively At median follow-up of 26.2 mo, 22 (59%) failed therapy; median time to treatment failure 7 mo

Toxicity

Investigator

No serious side effects noted

Stavropoulos et al.,7 2002

Mild and transient

Rajala et al.,8 2002

Drug tolerance excellent, with very low incidence of toxicity

Mohanty et al.,9 2002

AEs experienced by 37%, 37%, and 48% receiving 30, 50, and 80 mU IFN, respectively, and 55% receiving MM-C; severe AEs occurred in 9% of IFN and 10% of MM-C groups Well tolerated

Malmstrom,10 2002

No grade 3–4 toxicity encountered

Bazarbashi et al.,12 2000

O’Donnell et al.,11 2001

TUR (group 1) vs. TUR ⫹ 50 mU IFN-␣2b (group 2) vs. TUR ⫹ 100 mg epirubicin (group 3) immediately after TUR TUR (group A) vs. 40 mU of IFN-␣2b (group B) vs. 60 mU of IFN-␣2b (group C) vs. 80 mU of IFN-␣2b (group D) started 48–72 hr after TUR, given weekly for 2 mo, bimonthly for 4 mo, and monthly for 6 mo

283 patients, Ta–T1, G1– G3; 200 eligible for final analysis; 66, group 1; 66, group 2; 68, group 3 89 patients with primary or recurrent Ta–T1, G2; after TUR randomly allocated to group A (n ⫽ 20), group B (n ⫽ 22), group C (n ⫽ 24), and group D (n ⫽ 23)

Phase II

150 mg BCG (group 1) vs. 54 mU IFN-␣2a (group 2): administration weekly during first month, biweekly for 2 mo, and monthly for 9 mo

122 patients, recurrent T1, G1–G3

Phase II

60 mU IFN-␣2b (group 1) vs. double-distilled water (group 2): weekly instillation for 12 wk, once monthly for 1 yr

90 patients divided into 2 groups of 45 patients; only 78 patients evaluated

Phase I–II

60 mg low-dose BCG ⫹ IFN␣2b weekly for 6 wk; 3 patients assigned 10, 30, 60, or 100 ⫻ 106 U IFN␣2b ⫹ BCG

12 patients, Ta, T1, Tis, G2–G3

Phase II

Phase II

Group 3 had most favorable outcome, 45 (66%) of 68 without recurrence after 2 yr vs. 24 (37%) of 66 in group 2 and 26 (40%) of 66 in group 1 (log-rank test, P ⬍0.001)

Side effects mostly mild and transient, no differences among groups

Rajala et al.,13 1999

Follow-up of 36 mo. 33 patients had recurrence (13, 8, 7, and 5 in groups A–D). Recurrence rate was 65% for group A, compared with 36% (P ⫽ 0.06), 29% (P ⬍0.05), and 22% (P ⬍0.01) for groups B, C, and D, respectively. Differences in recurrence rates between the groups treated with IFN were not significant. 11 patients experienced progression in stage. The disease-free interval was 15 mo for group A, compared with 21.4 (P ⬍0.05), 26.1 (P ⬍0.001), and 30 mo (P ⬍0.001) for groups C– D, respectively. Disease-free intervals were different between all patients in groups B and D (P ⬍0.01) and for those with T1 in groups C and D (P ⬍0.01). 61 assessable in BCG group, 49 in IFN group; tumor recurred in 34 (69.4%) of 49 in IFN group and 24 (39.3%) of 61 in BCG group; differences in total number of recurrences (28 for BCG, 47 for IFN), disease-free interval (mean 19.3 mo for BCG, 15.3 mo for IFN), and index of recurrence (2.2 for BCG, 5.5 for IFN) statistically significant (P ⫽ 0.001) in favor of BCG; progression to invasive carcinoma similar in both study arms At 12 mo follow-up, relapse rate 28.2% (11 of 39) for IFN and 35.8% (14 of 39) for control group (P ⫽ NS); at 43 mo (range 9–67), relapse rate 53.8% (21 of 39) and 51.2% (20 of 39), respectively (P ⫽ NS); progression and mortality similar in both groups At 12 mo after treatment, no tumor progression; 6 had CR, 2 PR, and 1 treatment failure

No side effects of drug noted, nor was any adverse reaction reported by any patient

Giannakopoulos et al.,14 1998

Neither systemic nor local side effects seen in IFN group

Jimenez-Cruz et al.,15 1997

Local or systemic toxicity similar in both groups; toxicity virtually absent

Portillo et al.,16 1997

Safe and well tolerated; AEs mild to moderate and resolved at end of treatment

Stricker et al.,17 1996

TABLE I. (continued). Clinical Phase

Dose/Schedule

Patients

TUR only (group 1) vs. 50 mg epirubicin (group 2) vs. 50 mg epirubicin ⫹ 10 mU IFN␣2b (group 3): started 1 wk after TUR, weekly during first month and once a month for 1 yr 60 mU IFN-␣2b vs. 100 mU IFN-␣2b 7–15 days after TUR, weekly for 8 wk, bimonthly for 4 mo, monthly for 6 mo

81 patients, Ta–T1, G1– G2 randomized into three groups

Phase II

107 mU IFN-␣2b vs. 120 mg BCG (Connaught): 12 intravesical instillations for 1 yr starting 6 wk after TUR

78 patients prospectively randomized to 2 groups; Ta G2–G3, T1 G1–G3, Tis

Phase II

IFN-␣2b (50 ⫻ 106 IU) vs. mitomycin (40 mg): 8 instillations once weekly

287 patients, TaG2, T1G1–G2

Phase II

10 mU IFN-␣2b vs. 10 mU IFN-␣2b ⫹ 20 mg MM-C vs. 20 mg MM-C

Phase I–II

54 mU IFN-␣2a started 3–7 days after TUR, daily for 5 days for 2 wk High-dose IFN-␣2b (100 ⫻ 106 U) vs. low-dose IFN␣2b (10 ⫻ 106 U) vs. ethoglucid 1.13 g: 36 h after TUR, weekly treatment for 10 wk, monthly for 1 yr

67 patients, recurrent pTa–pT1 G1–G3 tumors randomized to 3 groups 20 patients, Ta–T1, G1– G2

Phase II

Phase II

Phase I–II

127 patients, Ta T1, all grades, no Tis (64 in 60-mU regimen, 63 in 100-mU regimen)

44 patients, Ta and T1 G1–G2 (13 in low-dose group, 11 in high-dose group, 10 in ethoglucid group)

Response

Toxicity

Patients followed up for mean 20 mo; 19 (63%) receiving intravesical chemoimmunotherapy (group 3) free of recurrence by end of first year and had longest disease-free interval compared with 3 of 19 in group 1 and 14 (44%) in group 2; difference in recurrence rates between groups in year 2 not statistically significant Of 64 receiving 60 mU, 26 had recurrence (33 at follow-up of 2.5 mo); of 63 receiving 100 mU, 21 had recurrence (26 recurrences at follow-up of 2.3 mo); recurrence rate per year for 60 mU and 100 mU, 0.13 and 0.11 and tumor rate per year 0.34 and 0.36, respectively After mean observation period of 24 mo (range 13–31) in BCG and 25 mo (6–32) in IFN group, 5 (15.6%) of 32 and 21 (60%) of 35 in BCG vs. IFN group had recurrence (P ⬍0.0003), respectively

Side effects mostly mild and transient; no differences found among groups

Raitanen et al.,18 1995

No side effects

da Silva et al.,19 1995

In IFN group, 18.4% had dysuria and 2.6% fever; in BCG group, 35% had fever, 60% cystitis, 1 patient each granulomatous epididymo-orchitis and pneumonitis with granulomatous prostatitis Treatment well tolerated in both arms

Kalble et al.,20 1994

MM-C superior to IFN with respect to time to recurrence and relative recurrence rate; difference particularly evident in patients with pTa G2 tumor After mean follow-up of 6.2 mo, no tumor recurrence seen in group receiving combined therapy; 4 of 22 in IFN group and 5 of 23 in MM-C group had recurrence After median follow-up of 98 wks, 15 (79%) of 19 evaluated patients (CI 60–91) disease-free; median relapse time 39.9 wk Median follow-up 36.5 mo (total follow-up 3 yr); recurrence rate 4.4% in low-dose and 2.76 in high-dose IFN group and 3.08 in ethoglucid group; low-dose IFN group, time to first recurrence 22.23 mo vs. 22.36 mo in high-dose group and 21.76 mo in ethoglucid group; progression occurred in 5 in IFN groups and none in ethoglucid group

Investigator

Boccardo et al.,21 1994

Side effects slight

Engelmann et al.,22 1992

No systemic adverse effects observed

Bartoletti et al.,23 1991

Neither systemic nor local side effects seen in IFN group; 3 patients withdrawn from ethoglucid because of severe chemocystitis

Hoeltl et al.,24 1991

Phase I–II

Low-dose IFN-␣2a (10 mU) vs. high-dose IFN-␣2a (100 mU): weekly for 12 wks, monthly for maximum of 1 yr

87 patients with Tis

Phase I–II

High-dose IFN-␣2b (100 ⫻ 106 U) vs. low-dose IFN␣2b (10 ⫻ 106 U): 8 doses in weekly intervals

19 patients with Tis

Phase I

Escalating doses of IFN-␣2b administered weekly for 8 wk: initial dose 50 ⫻ 106 IU, dose escalation 100– 1000 ⫻ 106 IU in groups of 3 patients

35 patients with highgrade intraepithelial neoplasia (17 Tis, 2 severe dysplasia, all cytology positive)

Phase I–II

54 ⫻ 106 IFN-␣2a, 8 weekly instillations

12 patients, Ta G1–G3, Tis

Of 47 high-dose and 38 low-dose patients, 20 (43%) and 2 (5%), respectively, achieved CR; PR (cytology results positive with no histologic evidence of Tis) noted in 23% of high-dose group; 6 of 9 with failure of prior intravesical BCG responded to IFN; among complete responders, 18 (90%) of 20 in high-dose group maintained responses for at least 6 mo after treatment (10 for ⬎12 mo); 7 in each treatment group underwent radical cystectomy; all 14 patients had progressive disease; median interval from initial treatment to cystectomy was 18 and 32 wk in low and high-dose groups, respectively; 100 mU produced significantly greater response rate (43% CR, P ⬍0.0001) than 10 mU (5% CR) Patients exhibited significantly greater CR at high dose than low dose(45% vs. 6%, respectively, P ⬍0.0001); 9 of 19 in high-dose CR group maintained CR for at least 6 mo; 5 patients in high-dose and 5 in low-dose group subsequently underwent cystectomy; median time to surgery was 33.5 wk for high-dose vs.18 wk for low-dose group Of 19 patients, 6 (32%) had complete resolution of all histologic and cytologic evidence of disease; additional 3 (16%) had complete resolution of Tis, but interval appearance of low-grade tumor recurrence; 5 (26%) had complete resolution of all evidence of Tis on bladder biopsies but persistently positive cytology; of 16 with recurrent tumors and extensive prior therapy, 4 (25%) had CR 2 PR, 1 no change, and 2 progressive disease in 5 patients with Ta tumors; of 4 patients with Tis, 1 CR, 1 PR, and 2 no change observed; of 3 with Tis and superficial papillary tumors, 1 had CR of Tis but no change of Ta tumor, other 2 had progressive disease

Local irritation or toxicity did not occur; other AE rare, except for mild to moderate flu-like symptoms (8% in lowdose and 17% in highdose group); none discontinued therapy because of treatmentrelated adverse effects

Glashan,25 1990

Intravesical IFN generally well tolerated

Chodak,26 1989

Minimal local and systemic toxicity

Torti et al.,27 1988

No systemic or local toxicity noted

Ackermann et al.,28 1988

KEY: TUR ⫽ transurethral resection; IFN ⫽ interferon; ␥ ⫽ gamma; ␣ ⫽ alpha; BCG ⫽ bacille Calmette-Gue´rin; MM-C ⫽ mitomycin-C; AEs ⫽ adverse events; CR ⫽ complete response; PR ⫽ partial response; CI ⫽ confidence interval; NS ⫽ not statistically significant.

propriate intravesical dosage seems to be in the range of 50 to 100 mU administered weekly for 6 weeks, as shown in an earlier multicenter randomized study considering the dose of IFN-alpha-2b. Patients treated with a high dose (100 mU) seemed to have a superior response compared with those given a low dose (10 mU). Durable responses to IFN, however, have been less clearly impressive than with BCG, possibly indicating that some other factor or combination of factors, such as the cellmediated cascade, is necessary for maximal beneficial effect. Also, intravesical IFN-alpha-2b seems to be more effective when used as the initial treatment, rather than as a salvage regimen in patients who have not responded to BCG. Combinations with mitomycin-C have been tested and have seemed to yield an advantageous response. Adverse reactions after intravesical IFN-alpha therapy have been relatively mild and include flu-like symptoms of fever, chills, fatigue, and myalgia, which occur in up to 27% of patients. Comparisons of adverse reactions with other, mostly chemotherapeutic, agents have shown a similar spectrum and percentage of side effects; however, because of study design limitations, statistical analysis has been difficult. In general, the results have not been encouraging and seem to indicate that BCG or chemotherapeutic agents are superior to IFN in the prevention of recurrence. A compilation of the available scientific data7–28 is shown in Table I. INTERLEUKIN-2 Recombinant human interleukin-2 (IL-2) administered systemically can mediate the regression of solid tumors in some patients. As is the case with IFNs, the principal idea of a possible IL-2 action on bladder cancer cells is derived from the role cytokines play during BCG treatment. At present, the major problem is determining the dose and scheduling. A broad range of schedules has been tried, and the study design has varied considerably. Most of the studies were poorly designed, lacked longterm results, and were hardly comparable. A compilation of the scientific data29 –32 is shown in Table II. INTERLEUKIN-12 Recombinant human IL 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. To date, only one Phase I study has evaluated intravesical recombinant human IL-12 administration in patients with Tis, Ta, or T1 tumors. Cohorts of 3 patients received 5, 20, 50, 100, and 200 ␮g intravesical recombinant human IL-12 weekly for 6 weeks. No patient experienced any systemic tox414

icity; the local adverse events included dysuria, urinary frequency and urgency, pain, hematuria, bladder spasms, and chills. Of the 12 patients without pretreatment lesions, 7 remained disease free and 5 experienced tumor recurrence within the 4-week follow-up period. Three patients with pretreatment Tis or Ta/T1 lesions had persistent disease during the post-treatment follow-up period.33 TUMOR NECROSIS FACTOR-ALPHA Several clinical trials were conducted to evaluate the efficacy of tumor necrosis factor-alpha in the treatment of superficial bladder cancer. The clinical use of recombinant tumor necrosis factor-alpha is strongly limited by its severe toxicity, mainly cardiovascular, when systemically administered. However, topical administration is free of significant toxicity and the systemic and local tolerability were excellent, even at the highest dose. Evaluation of Phase I and I-II studies suggested efficacy even in refractory superficial bladder cancer. However, the small trial sizes precluded extensive statistical assessment of the data. Most of the studies lacked long-term results and were hardly comparable. A compilation of the scientific data34 –37 is shown in Table III. KEYHOLE LIMPET HEMOCYANIN Keyhole-limpet hemocyanin (KLH), a highly antigenic respiratory pigment of the mollusc Megathura cranulata, is a nonspecific immune stimulator that has also been investigated as an intravesical agent. Jurincic-Winkler et al.38 reported on 13 patients with Tis who were treated with intravesical instillations of KLH, 20 mg for 6 weeks, and then monthly for 1 year and bimonthly for 2 subsequent years. Patients not responding to two courses of KLH were treated with BCG (81 mg, Connaught strain). Two patients were free of tumor after KLH instillations at a follow-up of 66 and 82 months. In their study, most patients with Tis had disease progression whichever substance was instilled, KLH or BCG. In another study, the investigators examined whether KLH was better than mitomycin-C in the prevention of superficial TCC recurrence.39 Lamm et al.40 reported a complete response in 50% of patients with Tis, 20% of patients with residual Ta and T1, and 33% of patients with both Tis and residual Ta-T1 treated with escalating doses of 2, 10, or 50 mg of intravesical KLH for 6 weeks. Flamm et al.41 compared KLH to ethoglucid for prophylaxis in 161 patients in whom other intravesical chemotherapeutic agents had failed and reported no difference in the mean disease-free interval and progression rate. These findings were, in part, confirmed in a study by Kalble et al.,42 who found that intravesical instillaUROLOGY 64 (3), 2004

TABLE II. Compilation of clinical studies with interleukin-2 (studies with incomplete data excluded) Clinical Phase

Patients

Response

Phase I–II

3 ⫻ 106 IU rIL-2 instilled on 5 consecutive days

10 patients, T1 after incomplete TUR

No toxic effects noted

Den Otter et al.,29 1998

Phase I–II

Continuous perfusion of rIL-2 in 3 different dose levels: 3 ⫻ 106 IU/day (3 patients), 9 ⫻ 106 IU/day (3 patients) and 27 ⫻ 106 IU/day (3 patients) Induction course of rIL-2 (10 daily instillations) with tumor in place using interpatient dose escalation scheme, 3– 18 ⫻ 106 IU/day; 7–14 days after end of induction course, 4 maintenance courses (10 daily instillations) started 1 mo after surgery, and done every 4 mo at dose of 6 ⫻ 106 IU/day 12 ⫻ 106 IU rIL-2, 8 weekly instillations

9 patients, Ta, T1G1–G3

8 (80%) of 10 marker lesions had completely regressed, no tumor cells on repeat biopsy; 4 patients remained tumor free after 30–54 mo At 6–12 mo of follow-up, all patients but 1 (with recurrence after 5 mo) were disease free; follow-up continued for another 12 mo, at which point 3 of 9 had relapsed Significant reduction in tumor diameters (staging done by sonography, CT scan, cytoscopy) observed in 5 of 25 interpreted as sign of biologic activity of rIL-2 regimen

AEs absent

Ferlazzo et al.,30 1996

No evidence of laboratory, local, or systemic toxicity

Tubaro et al.,31 1995

3 CR (duration of response of 9⫹, 3, 9 mo); 11 nonresponders for an overall response rate of 21%

1 had malaise for 24 hr after each treatment and 2 developed asymptomatic UTI

Gomella et al.,32 1993

Phase I–II

Phase I–II

Dose/Schedule

25 patients, Ta–T1N0M0, G1– G2, tumor left in place

14 patients, (13 Tis, Ta, T1, 1 Stage T2)

KEY: rIL-2 ⫽ recombinant interleukin-2; UTI ⫽ urinary tract infection; other abbreviations as in Table I.

Toxicity

Investigator

TABLE III. Compilation of clinical studies with tumor necrosis factor-alpha Clinical Phase

Dose/Schedule

Patients

Response

Phase I

Cohorts of 3 patients received 200, 400, and 1000 ␮g rTNF-␣ intravesically weekly for 11 wk (dwell time 2 hr)

9 patients, Ta, T1, Tis, ⱖ2 recurrences or within 6 mo of last TUR, ⱖ3 lesions

Not evaluated

Phase I

500 mg rTNF-␣ dissolved in 30 mL phosphate buffer (pH 7.6–7.8) plus 0.25% human albumin, administered weekly for 2 mo Increasing doses of rTNF-␣, 50–600 ␮g (group 1) and 500 ␮g rTNF-␣ continuously (group 2): 8 instillations at weekly intervals 400–1800 ␮g rTNF-␣: 8 ⫻ at single dose level twice a week for 4 wk

18 patients, Ta G1–G3

Of 15 assessable patients, 4 (26%) achieved CR

24 patients: group 1, toxicity and dosefinding (n ⫽ 11); group 2, efficacy (n ⫽ 13, Ta–T1 G1–G2) 20 patients (Ta, T1, Tis)

Phase I

Phase I–II

Toxicity

Investigator

MTD not achieved; 9 AEs, 8 of flu-like symptoms, 4 of headache, and 3 of chest tightness; hematologic and gastrointestinal toxicities were minor, no renal toxicity encountered; rTNF␣ was safe to administer up to 1000 ␮g Systemic and local tolerability excellent

Serretta et al.,35 1995

Group 2, 3 CR (23%) obtained; no change in 8; progression in 2

Tolerability excellent, even at highest dose

Serretta et al.,36 1992

Of 18 patients with marker lesion, 2 obtained CR for 8⫹ and 18 months; 2 had PR and were given other intravesical therapies after 5 and 7 mo; modest activity attained with intravesical TNF, even in pretreated patients

No or minimal systemic absorption of TNF observed by pharmacokinetic studies; well tolerated in doses up to 1800 ␮g; no systemic or local side effects observed

Sternberg et al.,37 1992

KEY: rTNF-␣ ⫽ recombinant tumor necrosis factor-alpha; MTD ⫽ maximal tolerated dose; other abbreviations as in Table I.

Glazier et al.,34 1995

tion therapy with KLH had only a slight prophylactic effect compared with BCG. The advantage of KLH is its apparent lack of toxicity. It seems to be an effective alternative immunotherapeutic agent. Therefore, it would appear to be an ideal treatment for patients with intermediate or even low-risk bladder tumors (Ta, grade 1-2), sparing many patients the side effects of BCG. Importantly, KLH would offer a therapeutic option in patients who are intolerant or refractory to BCG. However, additional research is necessary to identify the optimal dose and schedule of KLH immunotherapy. Additional research is also needed to determine whether KLH results in protection from disease progression, as seen with BCG therapy. A compilation of the scientific data38 – 42 is shown in Table IV. BROPIRIMINE Bropirimine is an aryl pyrimidine and augments endogenous IFN production. It possesses antiviral, antibiotic, anticancer, and immunomodulating activities by stimulating B-cell proliferation, natural killer cells, lymphokine-activated killer cells, and macrophage activity. A clinical Phase II study with bropirimine (U-54461S) orally administered at a dose of 750 mg every 2 hours, three times daily, for 3 consecutive days with a 4-day drug withdrawal was conducted in patients with Tis. Of 41 assessable patients, a complete response was observed in 17, no change in 18, and progressive disease in 6 patients; the overall efficacy rate was stated to be 41.5%. The frequently observed adverse drug reactions (Grade 2 or worse) were influenza-like symptoms such as fever and generalized malaise and gastrointestinal symptoms such as anorexia and nausea/vomiting. Additionally, abnormalities in laboratory tests, such as an elevation in glutamicoxaloacetic transaminase/glutamic-pyruvic transaminase, neutropenia, and leukopenia were observed. A follow-up investigation of these patients showed that the 1-year and 2-year recurrence-free rate was 70.3% and 61.5%, respectively (median follow-up 29.1 ⫾ 4.2 months).43 However, bropirimine was discontinued by the manufacturer in September 1996; the Food and Drug Administration Oncologic Drugs Advisory Committee voted against recommending approval of bropirimine owing to unresolved safety (significant cardiac-related toxicity) and efficacy concerns. A European Phase III clinical trial was closed prematurely by the sponsor. That study was originally designed to compare the effects of oral bropirimine with intravesical BCG in patients with newly diagnosed carcinoma in situ. A total of 55 BCG-naive patients with Tis were randomized to receive bropirimine (n ⫽ 27) or BCG (n ⫽ 28). Bropirimine was orally administered at a dose of 3 UROLOGY 64 (3), 2004

g/day for 3 consecutive days with a 4-day drug-free interval for up to 1 year. BCG instillations (Tice) were administered weekly for 2 ⫻ 6 weeks. The percentage of dropouts for all adverse events was 4% for bropirimine and 14% for BCG. The most frequently reported local events in the bropirimine-treated versus BCG-treated group were irritative complaints, 64% versus 89%, and hematuria, 24% versus 61%. The most frequently reported systemic events in the bropirimine-treated versus BCG-treated group were fever, 4% versus 21%; flulike syndrome, 24% versus 7%; headache, 28% versus 11%; and nausea, 24% versus 11%. Of the patients treated with bropirimine, 92% had a complete response, with a mean duration of 12.6 months. In the BCG group, all the patients had a complete response, with a mean duration of 12.3 months.44 To date, additional clinical investigation of bropirimine is pending. RUBRATIN (NOCARDIA RUBRA) Twelve patients with superficial bladder cancer were treated with intravesical instillations of Rubratin (ASTA Pharma AG, Frankfurt, Germany), a cell-wall preparation of Nocardia rubra. The objective was to compare the immunostimulating effect of Rubratin with that of BCG. Local immunostimulation was determined by cytokine induction in urine samples during the first 24 hours after each instillation, leukocyte influx into the urine, and phenotypic analysis of the lymphocyte fraction. The levels of Rubratin-induced IL1beta, IL-6, and tumor necrosis factor-alpha were significantly elevated compared with pretherapy levels. Rubratin induced leukocyte influx into the urine. It was shown to activate T cells and increase the CD4/CD8 cell ratio. Although local Rubratininduced immunostimulation occurred in a limited number of patients, the amount of immunocompetent cells attracted to the bladder seemed to be less than that associated with BCG therapy, resulting in lower levels of cytokine production.45 TRANSFORMING GROWTH FACTOR-ALPHAPSEUDOMONAS EXOTOXIN-40 Transforming growth factor-alpha-Pseudomonas exotoxin-40 (TP-40) is a hybrid fusion protein produced by recombinant technology that consists of a molecule of transforming growth factor-alpha fused to the Pseudomonas exotoxin PE-40. The protein selectively binds to cancer cells that express the epidermal growth factor receptor. TP-40 is then internalized and kills these cells by virtue of its Pseudomonas exotoxin-derived domains. In a clinical Phase I study, the safety and antitumor activity of intravesical TP-40 was evaluated in 43 patients with refractory superficial bladder cancer. 417

TABLE IV. Compilation of studies with keyhole limpet hemocyanin Clinical Phase Phase I–II

Phase I–II

Phase II

Phase II

Phase II

Dose/Schedule

Patients

Response

Toxicity

Investigator

20 mg KLH for 6 wk, monthly for 1 yr, bimonthly for 2 subsequent years; patients not responding to 2 courses of KLH treated with 81 mg BCG (Connaught strain) Escalating doses of 0.4, 2, 10, and 50 mg KLH weekly for 6 wk

13 patients with Tis

Follow-up 12–84 mo; 2 free of tumor after KLH instillations with follow-up of 66 and 82 mo; all patients who did not respond to primary KLH course, experienced recurrence 42, 48, 56, and 60 mo after first KLH instillation; 3 with recurrent Tis had recurrences after prolonged remission (4–5 yr)

No systemic or local side effects observed

Jurincic-Winkler et al.,38 2000

64 patients, Tis or residual Ta, T1

Toxicity of KLH minimal

Lamm et al.,40 2000

30 mg KLH weekly for 6 wk, monthly for 1 yr (group 1) vs. 0.565 g etoglucid (50 mL 1% solution) for 6 wk, monthly for 1 yr (group 2) 120 mg BCG (Connaught strain) vs. 10 mg KLH ⫹ immunized with 1 mg KLH intracutaneously weekly for 6 wk, 6–7 wk after TUR

161 patients, Ta– T1, G1–G3: group 1, 76; group 2, 85

Tolerability of KLH excellent

Flamm et al.,41 1994

1 had episode of fever, no other AEs

Kalble et al.,42 1991

10 mg KLH (group Ia and II [started later]): immunized with 1 mg KLH intracutaneously, monthly bladder instillations of 20 mg MM-C monthly (group Ib)

44 patients, Ta–T1, G0–G3

CR seen in 50% with Tis, 20% with residual Ta–T1, and 33% with both Tis and residual Ta–T1; responses occurred at all doses tested; no difference in response according to dose noted; optimal overall CR seen at 2 mg Mean follow-up 27.5 mo; no statistically significant differences found between two groups in percentage of recurrences (43.4% KLH vs. 53.9% etoglucid), recurrence rate (4.4 KLH vs. 3.9 etoglucid), mean disease-free interval (12.1 mo KLH vs. 13.6 mo etoglucid), or progression rate (6.5% KLH vs. 9.4% etoglucid) Mean follow-up 20 ⫾ 7 mo; 41.2% (7 of 17) of KLH and 14.3% (3 of 21) of BCG group developed recurrent bladder tumor; recurrence rate according to EORTC 1.95% in KLH group vs. 0.76 in BCG group; of 25 in BCG group, 15 (60%) had cystitis and 7 (28%) fever; only 1 (5.3%) of 19 in KLH group had cystitis Of 21 in KLH group Ia (mean follow-up 20.7 mo) 3 (14.2%) had recurrence compared with 9 (39.1%) of 23 in the MM-C group Ib (mean follow-up 18.3 mo); preventive effect better (P ⬍0.05) in KLH group than in MM-C group; of 81 in group II (mean follow-up 22.8 mo), 17 (20.9%) had recurrence; of KLH group, 20 (95.2%) of 21 in group Ia and 70 (86.4%) of 81 in group II had complete and partial prevention (downgrading) compared with 16 (69.5%) of 23 in group Ib

No adverse local or systemic side effects noted

Jurincic et al.,39 1988

42 patients, 38 of whom were evaluated, Ta G2–G3, T1 G1– G3, Tis

KEY: KLH ⫽ keyhole limpet hemocyanin; other abbreviations as in Table I.

The patients were treated with increasing dose levels of TP-40 at 0.15, 0.3, 0.6, 1.2, 2.4, 4.8, or 9.6 mg/wk for 6 weeks and evaluated by comparing the pretreatment and post-treatment cystoscopic examinations, cytology, and histopathologic findings. All TP-40 doses were well tolerated, and the maximal tolerated dose could not be determined. No evidence of antitumor activity was seen in any of the patients with Ta or T1 lesions. However, 8 of 9 patients with Tis exhibited a response based on the comparison of the pretreatment and post-treatment histopathologic analysis of multiple-site bladder biopsies after TP-40 therapy.46 Phase II studies have not been initiated. MISTLETOE LECTIN (PS76A2.13) Madaus (Cologne, Germany) is developing a recombinant form of mistletoe lectin as a potential cancer immunotherapeutic agent. In vitro, recombinant mistletoe lectin stimulates the release of cytokines and the expression of activation markers on lymphocytes and induces apoptosis of cancer cells.47 A study in a rat bladder cancer model provided evidence of an inhibitory effect of recombinant mistletoe lectin on experimental urothelial carcinogenesis.48 Phase I trials are presently being conducted in Germany. COMMENT Most studies evaluating instillation therapies in superficial bladder cancer have had patient cohorts that were remarkably heterogeneous concerning the panel of superficial bladder cancers. Stage Ta, grade 1-2 tumors commonly recur but rarely progress to lethal disease. The inclusion of T1 (invasive) cancers with Ta or Tis tumors in any study of intravesical chemotherapy or immunotherapy is problematic, because a T1 tumor in many cases shows a completely different biologic behavior concerning invasiveness and the ability to metastasize than a papillary tumor. In particular, Stage T1, grade 3 tumors are aggressive, and many centers decide to perform cystectomy before trying any instillation therapies, instead of risking tumor progression to a more advanced stage with all its consequences. The inclusion of patients with T1 cancer into clinical studies evaluating the efficacy of instillation therapy, who are more likely to have recurrence or progression because of incomplete resection, may dilute the effect seen in patients with Ta cancer. However, more problems exist with many intravesical treatment publications, including insufficient sample size, poor endpoints, poorly controlled or uncontrolled studies, and the grouping of grades 1 to 3 together, in addition to grouping the primary tumor stages of Ta, Tis, and UROLOGY 64 (3), 2004

T1 together. The interpretation of data from these clinical studies is difficult for even more reasons: (a) the studies contained patients with primary and recurrent bladder tumors without stratification on this parameter; (b) the studies contained patients with single or multiple bladder tumors; (c) the studies failed to calculate recurrence rates at specified endpoints (eg, 1 or 2 years after transurethral resection). Additionally, many potential variables exist in intravesical therapy, including the interval between starting intravesical therapy and performing transurethral resection, exposure period, volume of instillate, nature of the solvent, pH, and osmolality. Also, the dose and concentrations used in these studies were empirically derived and rarely tested systematically. An important unanswered question is when to start instillation therapy. A broad range of alternatives for starting instillation therapy, from 12 hours to 8 weeks after transurethral resection, has been applied, but most of them were also empirically derived. A comprehensive review of the published study by the American Urological Association Bladder Cancer Clinical Guidelines Panel49 found that only 181 of the 5712 reports examined met the minimal criteria, which included a study design with randomization of patients and an appropriate control group for inclusion into data analysis and extraction. Many negative studies did not have sufficient statistical power to identify differences in progression, further emphasizing the need to focus future evaluations on specific subgroups of patients with superficial bladder cancer who are at the greatest risk of experiencing adverse outcomes. The accuracy of endpoints in interpreting the results is contingent on the understanding of a disease, both at its initial presentation and in its ultimate capabilities. The efficacy of various treatments needs to be studied in this context, and the interpretations of outcomes need to be based on appropriate experimental designs, as well as the acquisition of meaningful endpoint data. However, the experience from these studies, comprising the understanding of complex immunologic context, permits future immunotherapies extending past the present “cytokine era.” Recent and future evolving approaches in biologic therapy with high-affinity antibodies, immunotoxins, peptide or protein vaccines, DNA vaccines, viral vaccines, dendritic cell vaccines, biologic molecules, tyrosine kinase modulators, or potent T-cell activators will enable targeted immunotherapies for (superficial) bladder cancer. CONCLUSIONS Intravesical BCG remains the most effective therapy in the management and prophylaxis of super419

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