Phase II trial of high-dose intermittent interleukin-2 in metastatic renal cell carcinoma: a Southwest Oncology Group study.

A phase II trial of intermittent high-dose recombinant interleukin-2 (rIL-2) was initiated to evaluate the response rate, remission duration, and toxic effects in patients with measurable metastatic renal cell carcinoma. The rIL-2 was administered as a bolus intravenous infusion at a dose level of 10.0 x 10(6) U/m2 three times weekly, preceded by indomethacin (50 mg orally). Dose reductions of rIL-2 for hypotension and other grade 3 or 4 toxic effects were permitted. Forty-four patients were entered and 41 were eligible. Previous treatment included nephrectomy (23 patients), radiation therapy (seven), and hormone therapy (three). Most toxic effects observed were moderate and included nausea, vomiting, anorexia (85%); hypotension (85%); fever, chills (78%); central nervous system changes (24%); myelosuppression (27%); and creatinine elevation (15%). Four instances of grade 4 toxicity were observed and included nausea, vomiting with dehydration; hypotension; and myocardial infarction. Thirty patients (73%) required dose adjustments because of toxicity. Five responses (12%) were seen, which included one complete and four partial. Sites of response included lung, liver, and soft tissue; the duration of response ranged from 2 to 20+ months. These results demonstrate that this schedule of rIL-2 can be administered in an outpatient setting, and can produce tumor regression in patients with metastatic renal cell carcinoma, including durable complete responses.

Phase I trial of spiromustine (NSC 172112) and evaluation of toxicity and schedule in a murine model.

Phase I evaluation of spiromustine was performed using an every-3-week schedule and a weekly X 3 schedule. Neurotoxicity was the dose-limiting toxicity presenting as alterations in cortical integrative functions (orientation, language, coordination), leading to a decrease in the level of consciousness. Traditional criteria for grading neurotoxicity poorly characterized these toxicities. The maximum tolerated dose was 6 mg/m2 every 3 weeks and 3 mg/m2 weekly X 3. Concurrent murine studies confirmed spiromustine as a schedule independent drug with toxicity correlating with peak plasma levels. Physostigmine had little effect on decreasing neurotoxicity in the murine model. The solvating agent used was not responsible for the neurotoxicity. Injection of spiromustine on a split-dose schedule decreased the acute neurological toxicity in mice and allowed a larger total dosage to be delivered (compared to single bolus dosage). Based on these results a split-dose schedule is suggested for future clinical trials.

Antitumor efficacy of interleukin-2 alone and in combination with adriamycin and dacarbazine in murine solid tumor systems.

Recombinant interleukin-2 (IL-2)/chemotherapy combinations have recently entered clinical trial. The rationale for sequencing has primarily been empiric or based on in vitro data. To establish in vivo models for chemoimmunotherapy trials, we investigated IL-2 alone and in combination with dacarbazine (DTIC) and adriamycin. IL-2 (as a single agent given i.v. at 1-3 x 10(5) Cetus units once daily for 5 days, repeated 7-10 days later), was highly active against an immunogenic line of colon adenocarcinoma no. 11/A [tumor growth inhibition (T/C) = 0% with cures]. It was modestly active against colon adenocarcinoma no. 38 (T/C = 39%), mammary adenocarcinoma no. 16/C (T/C = 18%), and B16 melanoma (T/C = 21%). IL-2 was inactive against colon adenocarcinoma no. 7/A (T/C = 83%). Combination trials were done using DTIC and IL-2 against colon no. 7/A and upstaged colon no. 11/A. The combination of adriamycin and IL-2 was tested against mammary adenocarcinoma no. 16/C. In the DTIC/IL-2 combination trials, the combination was superior over either agent used alone. In the IL-2/adriamycin trials, the combination was no better than adriamycin alone at optimum dosages.

Local administration of dendritic cells inhibits established breast tumor growth: implications for apoptosis-inducing agents.

Dendritic cells (DCs) can efficiently acquire foreign antigen(s) from apoptotic cells and induce MHC class I-restricted, antigen-specific CTLs. An accumulation of DCs within solid tumor masses in situ has been associated indirectly with a more favorable prognosis. Therefore, DCs may offer an efficient means for triggering immune responses within tumors, particularly in those masses containing significant apoptosis. We examined whether delivery of DCs could, alone, impact on the progressive growth of a tumor with a relatively high apoptotic index. We detected significant early apoptosis within the mass of a s.c. growing murine MT-901 breast carcinoma. DCs could efficiently engulf MT-901 tumor apoptotic cells in vitro. Intratumoral injections of syngeneic but not allogeneic DCs resulted in significant inhibition of MT-901 tumor growth. Histological examination of the tumor revealed intense mononuclear cell infiltration during and after DC injections. Tumor growth inhibition was relatively radiosensitive and dependent on host-derived CD8+ T cells. The baseline level of tumor apoptosis could be increased substantially by tumor necrosis factor alpha administration, leading to a greater DC-mediated antitumor effect. The antitumor effect could also be enhanced by first pulsing DCs with the foreign helper protein, keyhole limpet hemocyanin, prior to intratumoral delivery and combining it with the systemic administration of interleukin 2. Splenocytes from treated animals showed heightened levels of specific CTL activity and production of cytokines. The level of in situ tumor apoptosis appears to play a critical role in DC-mediated antitumor effects. The potential implication of these findings in DC-based tumor therapy strategies is discussed.

Phase II trial of paclitaxel and carboplatin in the treatment of advanced urothelial carcinoma.

PURPOSE: Both paclitaxel and carboplatin have single-agent activity against carcinoma of the urothelium. We evaluated the combination of paclitaxel and carboplatin in the treatment of advanced cancers of the urothelium. PATIENTS AND METHODS: Patients with cancers of the urothelium who had no prior chemotherapy (prior adjuvant chemotherapy > 6 months allowed) were eligible for treatment. Eligibility requirements were performance status of 2 or less, creatinine level less than 2.0 mg/dL, granulocyte count (AGC) 1,500/microL or greater, platelet count 100,000/microL or greater, and total bilirubin level less than 1.5 mg/dL. Paclitaxel 200 mg/m2 followed by carboplatin (area under the curve [AUC] 5, Calvert formula) were administered every 21 days. Patients were evaluated for toxicity weekly and assessed for response every 6 weeks. RESULTS: Thirty-six patients were entered onto the study and 35 patients were assessable for response. A total of 184 cycles were administered (median, six cycles per patient). Nine patients required one dose reduction, and seven patients required two dose reductions for a nadir AGC less than 500/microL, with only one episode of febrile neutropenia and sepsis. Myalgias and arthralgias of grades 1 to 2 occurred in 16 patients and usually lasted 2 to 3 days after treatment. There were no treatment delays because of toxicity. There were 18 responses; seven complete responses (CRs) and 11 partial responses (PRs) (response rate 51.5%; 95% confidence interval, 35 to 68). Median response durations for CR and PR were 6 and 4 months, respectively. Overall median survival was 9.5 months. CONCLUSION: The combination of paclitaxel and carboplatin is an active and well-tolerated regimen for the treatment of advanced urothelial carcinoma. Because of the modest toxicity of this combination, paclitaxel and carboplatin should be considered for addition to other agents with activity in urothelial carcinomas.

A phase I trial of recombinant interleukin-2 combined with recombinant interferon-gamma in patients with cancer.

Twenty-six patients with metastatic cancer were entered into a phase I trial of concurrent recombinant interleukin-2 (IL-2) and recombinant interferon-gamma (IFN-gamma). IL-2 was administered as a continuous intravenous infusion for 5 days. IFN-gamma was administered by a daily intramuscular (IM) injection during the 5 days of IL-2 administration. Treatment was repeated twice after 9-day rest periods. After a 2-week rest, patients without evidence of tumor progression were retreated. Natural killer (NK)- and lymphokine-activated killer (LAK)-cell activity were assayed in each patient before treatment, on day 1, and on day 5 of each cycle. Constitutional symptoms occurred in most patients but were not dose-limiting. Other toxicities included hypotension responsive to fluids, transient elevations in liver function tests, erythema/pruritus, eosinophilia, and transient leukopenia/thrombocytopenia. The maximum-tolerated dose (MTD) of the combination was 1 x 10(6) U/m2/d of IL-2 combined with 0.50 mg/m2/d of IFN-gamma. The dose-limiting toxicity was pulmonary manifesting as rales and shortness of breath. The dose of the combination that resulted in the optimal generation of in vivo LAK-cell activity was a dose of at least 0.25 mg/m2/d of IFN-gamma combined with 1 x 10(6) U/m2/d of IL-2. Objective clinical responses were seen in five of 26 patients. These included a partial response of 2 months duration in a patient with non-Hodgkin's lymphoma (NHL), mixed responses in a patient with NHL and two patients with renal cell carcinoma (RCC), and an ongoing assessable response in a patient with bone metastases from RCC. The recommended dose for phase II trials of this combination is 0.50 mg/m2 of IFN-gamma and 1 x 10(6) U of IL-2.

Southwest Oncology Group Study of paclitaxel and carboplatin for advanced transitional-cell carcinoma: the importance of survival as a clinical trial end point.

PURPOSE: The combination of paclitaxel and carboplatin for the treatment of advanced transitional-cell carcinoma (TCC) of the urothelium has promising activity and acceptable toxicity. The purpose of this trial was to evaluate the efficacy of this regimen in a cooperative group setting. PATIENTS AND METHODS: Twenty-nine patients with advanced TCC were treated every 21 days with paclitaxel 200 mg/m(2), administered as a 3-hour infusion, followed by carboplatin dosed to an area under the curve of 5. Prior systemic adjuvant or neoadjuvant platinum-based therapy was not permitted unless completed at least 1 year before enrollment. Patients were evaluated for response every three cycles, and follow-up was conducted to determine survival. RESULTS: Twenty-nine patients were enrolled and were assessable. Four (14%) had received prior adjuvant or neoadjuvant therapy. Node-only disease was present in 24%, and 76% of patients had extranodal disease. The median number of cycles received was five. Grade 4 toxicity consisted primarily of neutropenia (38% of patients). Neurologic toxicity was noted in 16 patients (grade 1 in four patients, grade 2 in five patients, grade 3 in six patients, and grade 4 in one patient). Six partial responses and no complete responses were noted, for a response proportion of 20.7% (95% confidence interval, 8% to 40%). Median progression-free survival time was 4 months, and overall survival time was 9 months. CONCLUSION: The combination of paclitaxel and carboplatin for the treatment of advanced TCC is reasonably well tolerated. However, a response proportion considerably lower than that previously reported was noted. In addition, the median survival time of 9 months was less than the survival time previously reported for patients treated with the combination of methotrexate, vinblastine, doxorubicin, and cisplatin. Although our results may reflect enrollment of patients with poor prognostic features, they also call into question the utility of this regimen.

Phase II trial of sequential radiation and interleukin 2 in the treatment of patients with metastatic renal cell carcinoma.

We have previously demonstrated that local tumor irradiation effectively enhanced the therapeutic effect of interleukin 2 (IL-2) therapy in an experimental murine renal adenocarcinoma model. Based on these preclinical studies, we have designed and initiated a Phase II trial of irradiation combined with IL-2 for the treatment of metastatic renal cell carcinoma. Patients received 800 cGy to the primary or metastatic lesions on days 1 and 15 followed by IL-2 (600,000 IU/kg i.v.) every 8 h on days 4-8 and 18-22. Sixteen patients were entered; all completed treatment and are therefore evaluable for toxicity and response. Two partial remissions were seen for a response rate of 12.5% (95% confidence interval, 0-28.7). There was no increase in toxicity over that which is anticipated from IL-2 alone. The antitumor activity seen in this trial is consistent with what would be expected from high-dose IL-2 alone.

Treatment of metastatic cancer with tetrathiomolybdate, an anticopper, antiangiogenic agent: Phase I study.

Preclinical and in vitro studies have determined that copper is an important cofactor for angiogenesis. Tetrathiomolybdate (TM) was developed as an effective anticopper therapy for the initial treatment of Wilson's disease, an autosomal recessive disorder that leads to abnormal copper accumulation. Given the potency and uniqueness of the anticopper action of TM and its lack of toxicity, we hypothesized that TM would be a suitable agent to achieve and maintain mild copper deficiency to impair neovascularization in metastatic solid tumors. Following preclinical work that showed efficacy for this anticopper approach in mouse tumor models, we carried out a Phase I clinical trial in 18 patients with metastatic cancer who were enrolled at three dose levels of oral TM (90, 105, and 120 mg/day) administered in six divided doses with and in-between meals. Serum ceruloplasmin (Cp) was used as a surrogate marker for total body copper. Because anemia is the first clinical sign of copper deficiency, the goal of the study was to reduce Cp to 20% of baseline value without reducing hematocrit below 80% of baseline. Cp is a reliable and sensitive measure of copper status, and TM was nontoxic when Cp was reduced to 15-20% of baseline. The level III dose of TM (120 mg/ day) was effective in reaching the target Cp without added toxicity. TM-induced mild copper deficiency achieved stable disease in five of six patients who were copper deficient at the target range for at least 90 days.

Reversible cardiomyopathy after high-dose interleukin-2 therapy.

We observed two patients who developed moderate global myocardial dysfunction during therapy with high-dose interleukin-2 (IL-2). Although cardiac enzymes became markedly elevated at the completion of a full course of IL-2, patients exhibited no ischemic symptoms. Serial echocardiography documented global myocardial dysfunction, which resolved in 5 days in one patient but persisted beyond 4 weeks in another. Asymptomatic reversible myocardial injury can occur with high-dose IL-2 and can persist beyond 4 weeks after stopping therapy. Review of the literature suggests an IL-2-associated myocarditis as an etiology.

Sequential dacarbazine/cisplatin and interleukin-2 in metastatic melanoma: immunological effects of therapy.

Thirteen previously untreated patients with metastatic melanoma entered into a phase II chemo-immunotherapy trial were monitored immunologically during treatment. Treatment consisted of dacarbazine (DTIC) 750 mg/m2 and cisplatin 100 mg/m2 on day 1 followed by interleukin-2 (IL-2) 4 x 10(6) U/m2 by daily intravenous bolus on days 12-16 and 19-23. Cycles were repeated every 28 days. On days 1 (pretreatment), 12, 16, and 23 of each cycle, lymphokine-activated killer (LAK) cell and natural killer cell activity as well as total lymphocyte count and CD3, CD4, CD8, and CD56 lymphocyte subsets were analyzed. Despite pretreatment with full-dose cytotoxic chemotherapy, all patients were able to respond immunologically to IL-2. Spontaneous LAK cell activity was generated by the end of each course of IL-2 administration and persisted for at least 5 days thereafter. Lymphocytosis was maximum at 5 days after IL-2 administration and included increased numbers of all measured lymphocyte subsets. IL-2 administration caused a relative increase in CD56+ cells and a relative decrease in CD3+ cells. There was a direct correlation between the increase in LAK cell activity and the increase in CD56+ lymphocytes. Antitumor responses occurred in five patients but these responses did not correlate with any of the measured changes in LAK activity or lymphocyte subsets. DTIC and cisplatin administered in this schedule does not abrogate the immunological effects of IL-2.

Phase I trial of recombinant macrophage colony-stimulating factor by rapid intravenous infusion in patients with cancer.

Fourteen patients were entered into a phase I dose-escalation trial of macrophage colony-stimulating factor (M-CSF). M-CSF was administered to inpatients by rapid 15 min i.v. infusion every 8 h x 5 days, repeated after a 9-day rest. Dose levels evaluated were 20, 40, 80, 330, and 1,100 micrograms/m2. Monitoring of patients every 4 h included vital signs, daily complete blood count (CBC), and serum chemistries (SGOT, creatinine, and bilirubin) while receiving M-CSF. No clinical or laboratory evidence of toxicity was seen. The average serum t1/2 varied with dose level. At 330 and 1,100 micrograms/m2, the serum t1/2 was 25 and 84 min, respectively, implying a saturable mechanism of clearance. After 5 days of treatment, the t1/2 decreased by twofold, consistent with enhancement of the saturable mechanism. Monocyte cytotoxicity against the A375 melanoma cell line was evaluated pretreatment and day 5 of each cycle. No consistent enhancement of monocyte cytotoxicity was seen. No effect on peripheral blood monocyte number was seen until the 1,100 micrograms/m2 dose level. At this dose level, the mean monocyte number on day 5 was increased compared to baseline (1,300 mm3 vs. 300/mm3). Clinical activity was seen in two patients with previously progressive leiomyosarcoma metastatic to the liver. A partial response (PR) lasting 7 months occurred at the 330 micrograms/m2 dose level while a patient treated at 1,100 micrograms/m2 has had stable disease for 20+ months. The maximum tolerated dose (MTD) of M-CSF was not determined. Based on clinical responses, a phase II trial is warranted in patients with metastatic soft tissue sarcoma.

A phase II trial of oral diethylstilbesterol as a second-line hormonal agent in advanced prostate cancer.

OBJECTIVES: To test the use of 1 mg/day of oral diethylstilbesterol (DES) as a treatment for patients with advanced prostate cancer who had failed primary hormonal therapy. Approximately 40,000 men this year will experience first-line hormonal therapy failure for their metastatic prostate cancer. At this time there is no standard therapy for men whose first-line hormonal manipulation has failed. This clinical problem has been exacerbated by the use of prostate-specific antigen (PSA) as a proved biomarker to follow disease progression. Patients who are experiencing hormonal therapy failure now present with a rising PSA, and virtually all are asymptomatic. The dilemma of how to treat these patients represents a new clinical problem for the medical oncologist and urologist that needs to be answered. METHODS: We conducted a Phase II trial of oral DES in 21 patients. Patients were followed for response by PSA criteria and toxicity. A decrease in two serial measurements of PSA of greater than 50% from baseline was judged to be a partial response. RESULTS: Nine of 21 patients achieved a PSA response (43% response rate with 95% confidence intervals of 22% to 64%) leading to early cessation of this Phase II trial. Eight of 13 patients (62%) who had only one prior hormone manipulation that failed demonstrated a PSA response, whereas only 1 of 8 patients (13%) who had received two or more hormone treatments responded (P = 0.07). The median follow-up is 82 weeks (range 8 to 122) among 16 surviving patients. The survival rate at 2 years is 63% (95% confidence interval 41% to 99%). CONCLUSIONS: DES appears to be an active agent for second-line hormone therapy for metastatic prostate cancer. Because it has been taken off the market for economic reasons, DES should be considered for development under the orphan drug strategy.

A phase II trial of oral estramustine and oral etoposide in hormone refractory prostate cancer.

OBJECTIVES: We previously demonstrated that the combination of oral estramustine (15 mg/kg/day) and oral etoposide (50 mg/m2/day) is effective first-line therapy for the treatment of hormone refractory prostate cancer. We initiated a new Phase II trial utilizing a lower dose of estramustine (10 mg/kg/day) and allowing previous chemotherapy treatment. METHODS: Estramustine (10 mg/kg/day) and etoposide (50 mg/m2/day) were administered orally for 21 of 28 days. Sixty-two patients were enrolled with a minimum of 26 weeks of follow-up. RESULTS: Of 15 patients with measurable soft tissue disease, 8 (53%) had a partial response (PR). Seven of these 8 patients also demonstrated a decrease in baseline prostate-specific antigen (PSA) of more than 50%. The median survival of all patients was 56 weeks. Of 47 patients with disease limited to the bone, 16 (34%) had a PR to therapy based on decrease in pretreatment PSA of more than 50%. Overall, 24 (39%) of 62 patients demonstrated a decrease in pretreatment PSA levels of at least 50% from baseline. Twenty-two patients received previous chemotherapy. There were no differences in survival or disease response in patients treated with previous chemotherapy compared with untreated patients. Pretreatment hemoglobin, PSA, alkaline phosphatase and lactate dehydrogenase levels were not significant prognostic factors, but performance status was an important predictor of survival. CONCLUSIONS: We conclude that the combination of oral estramustine (10 mg/kg/day) and oral etoposide (50 mg/m2/day) is an active regimen for hormone refractory prostate cancer.

Supportive care, pain management, and quality of life in advanced prostate cancer.

Despite achievements in the area of providing care for patients with advanced prostate cancer, ample work remains. Additional research is needed regarding the control of pain from bone metastases and the management of fatigue and urinary symptoms. Investigators have only begun to explore the area of quality of life research in patients with prostate cancer. Other issues not addressed in this article that are significant to the care of these patients include caregiver burden and end-of-life care. These areas significantly affect quality of life. The supportive care, pain management, and quality of life issues discussed herein present many challenges to health care providers. Close attention to what patients tell us about their care will make the challenge more attainable and the caregiving more satisfying.

Low-dose continuous infusion 5-fluorouracil and cisplatin: phase II evaluation in advanced colorectal carcinoma.

A study was performed to evaluate the combination of low-dose continuous infusion 5-fluorouracil (LDCI-FU) (300 mg/m2 daily for 28 days) and cisplatin (20 mg/m2 days 1-5 and 24-28). Patients were treated for 28 days with a subsequent 14-day rest period. A total of 24 patients were entered on the study and were evaluable for response and toxicity. All patients were previously untreated, with a median age of 61.5 years and median performance status of 70% (Karnofsky). Bidimensional measurable disease was required. Complete responses were noted in 2 of 24 (8%) patients lasting 8+ and 9 months. Partial responses were observed in 8 of 24 (33%), with a median duration of response of 6 months. Median survival for the 24 patients was 9+ months. Toxicities included nausea and vomiting (25%), hand-foot syndrome (21%), diarrhea (4%), myelosuppression (21%), neurotoxicity (13%), gastric ulceration (13%), mucositis (17%), nephrotoxicity (4%), and subclavian vein thrombosis (21%). This combination demonstrated antineoplastic activity; however, its efficacy parallels other trials utilizing both single agent 5-fluorouracil (5-FU) and different variations of the 5-FU/cisplatin in combination. The impact of this combination on survival and comparison to other regimens requires a randomized trial.

Phase I study of monoclonal antibody-ricin A chain immunoconjugate Xomazyme-791 in patients with metastatic colon cancer.

The immunoconjugate XMMCO-791/RTA consists of ricin A chain bound to a murine monoclonal antibody MoAb 791T. This monoclonal antibody (MoAb) binds to a glycoprotein of 72 kD, which is expressed on human colorectal carcinoma, ovarian carcinoma, and osteogenic sarcoma. XMMCO-791/RTA was tested in a Phase I trial with proposed dose escalation steps of 0.02, 0.04, 0.15, and 0.2 mg/kg per day. Twelve patients with metastatic colorectal carcinoma were treated at 0.02, 0.03, and 0.04 mg/kg per day dose levels administered over 1 hour on days 1-5. Study-related toxicities were hypotension (6 patients); greater than 10% weight gain (6 patients); peripheral edema (9 patients); fever (4 patients); confusion (3 patients); diarrhea (3 patients); proteinuria, as identified by dipstick (3 patients), greater than 0.6 mg/dl decrease in serum albumin (11 patients); greater than 25% decrease in oncotic pressure (10 patients), and a decrease in ionized calcium (8 patients). Six patients received a second course of treatment. HAMA levels developed in 9 patients and titers increased with number of courses administered. Decreased overall toxicity, in comparison to the first course, was noted, but one patient had an allergic-type response (hypotension, crushing chest pain, diaphoresis) after the test dose of the second course (HAMA level > 10,000 IgG). Life-threatening toxicity in the form of fluid shift, resulting in noncardiac pulmonary edema and third-spacing occurred after course 1 in 1 of 3 patients at the 0.04 mg/kg per day level. No further dose escalation was attempted and no antitumor activity was seen.

A phase II evaluation of oral tamoxifen and intermittent intravenous vinblastine in hormone-refractory adenocarcinoma of the prostate.

Hormone refractory prostate carcinoma is an incurable disease. Therapy affecting the tissue matrix at the level of the cytoskeleton has been demonstrated to inhibit prostate cancer growth. In vivo and in vitro evidence demonstrated vinblastine and tamoxifen to be agents that would interact to inhibit prostate cancer growth by microtubule inhibition. This study evaluated the effectiveness of these agents in combination in 22 patients with metastatic hormone refractory prostate cancer. Patients received tamoxifen 20 mg twice daily continuously plus vinblastine 4 mg/m2 on days 1, 8, 15, 22, 28, and 35 every 49 days. Disease response was assessed after the first two cycles of therapy. No partial or complete responses were definitively identified. Only 23% of participants received two or more full cycles of therapy. Major toxicities included grade 1-3 leukopenia (73%), grade 2-3 anemia (64%), and two participants experienced a grade 3/4 thrombocytopenia. Only two participants experienced a greater than 50% decrease in serum PSA, one of which may have been attributed to a flutamide withdrawal syndrome. We conclude that the dosage and schedule of vinblastine and tamoxifen used in this study is inactive in the treatment of metastatic hormone refractory prostate cancer.

Effect of calcium replacement on the hemodynamic changes associated with high dose interleukin-2 therapy.

Administration of high-dose IL-2 results in hemodynamic changes that are similar to those seen in septic shock. These include a decrease in systemic vascular resistance (SVR) with a resultant drop in mean arterial pressure (MAP). Hypocalcemia is seen in septic shock and with IL-2 administration. Calcium replacement in septic shock has been reported to result in hemodynamic improvement; we therefore administered calcium to patients receiving high dose IL-2 to correct ionized hypocalcemia. Five consecutive patients underwent invasive hemodynamic monitoring before and during IL-2 administration. Calcium chloride was administered to correct ionized hypocalcemia, and hemodynamic parameters were monitored before and after calcium administration. Ionized hypocalcemia was associated with an elevation in parathyroid hormone levels. There was no toxicity related to the administration of calcium. An improvement in the MAP and SVR was seen early and late (after a dose of IL-2 was held) in the IL-2 treatment cycle; there were minimal effects at other points. Because of the potential hemodynamic benefit of calcium replacement, we recommend that ionized hypocalcemia be corrected in patients receiving high-dose IL-2.