A phase III randomized study of oral verapamil as a chemosensitizer to reverse drug resistance in patients with refractory myeloma. A Southwest Oncology Group study.

BACKGROUND: Multiple myeloma is considered to be a drug responsive disease; however, there is no cure for this disease and virtually all patients will develop drug resistance. One form of drug resistance that has been documented is the multidrug resistance phenotype or MDR. METHODS: A randomized trial of the combination of vincristine, doxorubicin, and dexamethasone (VAD) and VAD plus oral verapamil (VAD/v) in drug refractory multiple myeloma patients was performed by the Southwestern Oncology Group. Verapamil was used as a chemosensitizing agent to attempt to overcome or prevent MDR and improve the therapeutic outcome. RESULTS: Response rates between the two treatment arms were similar with an overall response rate of 41% for the VAD alone arm and 36% for the VAD/v arm. Overall survival of patients was also similar with a median survival of 10 months for the VAD arm and 13 months for the VAD/v arm. The toxicity profile was also similar for both treatments, with myelosuppression being the dose-limiting toxicity. No significant correlation was observed between expression of P-glycoprotein, serum verapamil levels, and response to therapy. CONCLUSIONS: No beneficial effect was observed from the addition of oral verapamil to the VAD chemotherapy regimen for the treatment of drug-resistant myeloma patients. More effective and less toxic chemosensitizers are needed to study the role of chemosensitizers in reversing MDR in the clinic.

Efficacy of prednisone in refractory multiple myeloma and measurement of glucocorticoid receptors. A Southwest Oncology Group study.

BACKGROUND: Prednisone is an active drug in the treatment of multiple myeloma. The optimal dose, frequency, and role of glucocorticoid receptors (GR) in response to prednisone is unknown. PURPOSE: The purposes of this study were (1) to estimate the response rate of alternate-day high dose prednisone in patients with relapsing and refractory multiple myeloma; (2) to measure the rate of GR levels; and (3) to correlate the response of prednisone with GR status. PATIENTS AND METHODS: Between 8/86 and 1/90, 127 patients were entered onto the study with 121 evaluable for response. The number of GR sites/cell was determined on mononuclear cells isolated from pretreatment bone marrow aspirates using a one point GR binding assay. Patients received prednisone 100 mg po qod x 2 weeks, followed by 50 mg po qod x 10 weeks. RESULTS: The overall response rate was 10% (95% CI: 5-15%) with a median survival of 11.8 months. The GR sites/cell ranged from 0-53,212 with a mean of 8,371 sites/cells. Stratification of GR sites into 0-2,500, 2,501-6,000 and > 6,000 sites/cells was associated with a response rate of 6%, 27% and 4% respectively (p = 0.009). The median survival of patients in these categories was 8.1, 14.9 and 10.6 months respectively. This was not significant by the logrank test (p = 0.11). Although myeloma patients with intermediate levels of GR sites/cell initially responded more favorably to prednisone, their long-term survival was not significantly improved. CONCLUSIONS: Alternate-day high-dose prednisone was well tolerated and may provide palliative benefit for a subset of patients with relapsing and refractory multiple myeloma. The survival of patients on this study was comparable to that reported with other but more toxic doses of glucocorticoids.

Phase II studies of recombinant human tumor necrosis factor alpha in patients with malignant disease: a summary of the Southwest Oncology Group experience.

From June 1988 to November 1990 the Southwest Oncology Group initiated nine protocols for the phase II evaluation of recombinant human tumor necrosis factor alpha (rhuTNF alpha) in cancer patients. Patients with diverse metastatic malignancies including breast, colon, gastric, pancreatic, endometrial, and bladder cancers, as well as multiple myeloma and various sarcomas received 150 micrograms/m2 of rhuTNF alpha daily for 5 days every other week. Of 147 patients entered in the study, 127 were eligible and were evaluated for toxicity and response. Of 124 patients known to have completed treatment, 92 (74%) went off study for progression, 21 (17%) for toxicity, and 12 (10%) for other causes, mainly that of worsening medical condition. Thirteen percent of patients experienced grade 4 or fatal toxicity. The most serious toxicities were pulmonary failure and coagulopathies. The predominant grade 3 toxicities were symptomatic (chills, fever, malaise, headache, myalgia, and nausea or vomiting). Only one partial remission was seen in a patient with metastatic bladder cancer lasting 4 months (rate 0.8%, exact 95% confidence interval 0-4%). At the study dose and schedule, rhuTNF alpha does not appear to have significant antitumor activity. The biological basis for this finding is discussed.

Phase III comparison of doxorubicin and dacarbazine given by bolus versus infusion in patients with soft-tissue sarcomas: a Southwest Oncology Group study.

Disseminated soft-tissue sarcomas are a group of uncommon malignancies generally treated in a uniform manner. This study questioned the impact of schedule on response rate and toxicity in patients with metastatic soft-tissue sarcoma treated with the two-drug combination doxorubicin and dacarbazine. Patients were randomly assigned to receive either bolus therapy with doxorubicin at a dose of 60 mg/m2 and dacarbazine at a dose of 750 mg/m2 intravenously on day 1 (118 patients) or infusional therapy with doxorubicin at 60 mg/m2 and dacarbazine at 750 mg/m2 delivered by continuous intravenous infusion for 96 hours on days 1-4 (122 patients). Chemotherapy was to be repeated every 3 weeks. A unique feature of this cooperative group protocol was a provision for surgical resection of residual disease in patients with a partial response or with stable disease following chemotherapy. Similar overall response rates (17% in both treatment arms) and complete response rates (5% in both treatment arms) were observed. For patients receiving bolus therapy, the median response duration was 19.6 months for those in complete remission and 6.6 months for those in partial remission. For patients receiving infusional therapy, the median response duration was 12.6 months for those in complete remission and 9.3 months for those in partial remission. Examination of dose intensity received when combining treatment arms revealed a weak doxorubicin dose-response relationship. There was no difference in median survival times between the two treatment arms (bolus therapy, 10.6 months; infusional therapy, 10.5 months; logrank P = .97). Analysis of toxic effects favored infusional therapy. Significant reductions in cardiac toxicity (all events, P = .04; clinical events, P = .01) and nausea and emesis (P = .04) were seen in infusional therapy. Of 47 patients eligible for cytoreductive surgery following chemotherapy, 12 received surgery, and of those 12, eight were rendered disease free. The use of a 96-hour continuous intravenous infusion of doxorubicin-dacarbazine was comparable therapeutically with bolus dosing of these two agents and was better tolerated by the patients.

Evaluation of amonafide in refractory and relapsing multiple myeloma: a Southwest Oncology Group study.

This study involved the administration of amonafide intravenously 300 mg/m2 daily times five days every three weeks to 16 refractory and relapsed myeloma patients. Doses were escalated to toxicity. These doses caused severe thrombocytopenia and granulocytopenia in seven patients. No responses were seen in this heavily pretreated group of patients.

Alternated versus syncopated CHOP-PVB: two studies for the treatment of non-Hodgkin's lymphoma by the Southwest Oncology Group.

Based on a preliminary trial that suggested that CHOP (cyclophosphamide, doxorubicin, vincristine, prednisone), and PVB (cisplatinum, vinblastine, bleomycin), are at least partially non-cross-resistant, the Southwest Oncology Group treated patients with unfavorable histology, non-Hodgkin's lymphoma with CHOP and PVB. In the first study, 76 eligible patients were given three courses of CHOP, with complete or partial responders receiving three courses of PVB followed by three further courses of CHOP. Nonresponders after the initial three cycles of CHOP, received six courses of PVB. In the second study, 154 eligible patients were treated with alternating cycles of the two drug regimens. The overall objective antitumor response (CR + PR) was 77% for the first study and 58% for the second. The complete remission rates were 48% and 38%, respectively. The overall survival for both studies is similar. These results are interpreted in terms of the Goldie-Coldman hypothesis.

Chemotherapy is superior to sequential hemibody irradiation for remission consolidation in multiple myeloma: a Southwest Oncology Group study.

Six hundred fourteen previously untreated patients with multiple myeloma were evaluated on this phase III Southwest Oncology Group (SWOG) trial. For remission induction, two noncross-resistant drug combinations (vincristine, melphalan, cyclophosphamide, and prednisone [VMCP] and vincristine, carmustine [BCNU], Adriamycin [doxorubicin; Adria Laboratories, Columbus, OH], and prednisone [VBAP]) were administered with either a direct alternating or a syncopated schedule. Pretreatment serum beta-2 microglobulin (beta 2M) was the single most important prognostic factor for survival (P less than .0001). There was no difference in toxicity, response, or survival by induction chemotherapy schedule (P greater than .7). For consolidation, 180 eligible and responsive patients were randomized to receive either an additional year of VMCP or sequential hemibody radiation (HBI) with vincristine and prednisone (VP) administered between the two HBI courses. Relapse-free survival (26 months) and overall survival (median, 36 months) were better with VMCP than with HBI (median, 20 months and 28 months; P = .04 and .018, respectively). HBI was also evaluated on a nonrandomized basis in 66 patients who achieved either a partial response (PR) or who were nonresponders to induction therapy. While HBI converted 24% of the PR patients to remission status, this effect was only seen in 5% of nonresponding patients. The survival of responsive and nonresponding patients receiving HBI was similar. All HBI groups had an inferior outcome to those receiving VMCP consolidation. Myelosuppression was also significantly worse after HBI. Survival from the time of relapse did not differ between patients randomized to receive VMCP or HBI. Thus HBI induced less durable remissions, but did not render patients less amenable to postrelapse chemotherapy. Our findings do not support the use of HBI in either chemotherapy responsive or nonresponding patients with multiple myeloma.

Phase II study of fludarabine phosphate in multiple myeloma. A Southwest Oncology Group study.

Thirty-one patients with multiple myeloma refractory to therapy or relapsing after response to initial therapy were treated with Fludarabine Phosphate utilizing a daily intravenous schedule for five consecutive days. There were no objective responses seen and only one patient showed clinical improvement. Myelosuppression manifest as leucopenia and granulocytopenia was the primary toxicity seen. Fludarabine Phosphate is inactive in previously treated myeloma patients when given by the daily intravenous route.

Aclacinomycin A in the treatment of multiple myeloma: a Southwest Oncology Group study.

Fifty-two patients with progressive resistant multiple myeloma were entered in this Southwest Oncology Group Phase II study, using weekly intravenous Aclacinomycin A. Of forty-three evaluable patients for response, there was one partial remission of 2 years duration and two sustained clinical improvements with 25% reduction in paraprotein. Major toxicity seen was severe myelosuppression and significant nausea and vomiting requiring dose reduction and delay of the scheduled treatment. Cardiac arrhythmia was seen in one patient. Chronic daily schedule or continuous IV infusion is recommended for future study.

A-phase II study of intravenous 6-thioguanine (NSC-752) in multiple myeloma. A Southwest Oncology Group study.

Thirty-three patients with relapsing or refractory multiple myeloma were treated with 6-Thioguanine (6TG) at a dose of 1 g/M2, with therapy given over four hours every three weeks. The major toxicity seen was myelotoxicity; thrombocytopenia was more commonly noted than neutropenia. One patient achieved a PR, two were clinically improved. 6TG in this short infusion schedule proved to be myelotoxic, but demonstrated little activity in previously treated myeloma patients.

A useful high-dose intermittent schedule of adriamycin and DTIC in the treatment of advanced sarcomas.

One-hundred-fourteen evaluable patients with metastatic soft tissue or bony sarcoma with measurable disease were treated with Adriamycin (doxorubicin) administered intravenously at a dose of 60 mg/M2 on day 1, followed by DTIC (dacarbazine) at a dose of 750 mg/M2; courses were administered at 3-week intervals. Ten complete remissions and 17 partial remissions were observed. The most responsive cell type was malignant fibrous histiocytoma with a response rate of 54%. This treatment schedule was very well tolerated, with only moderate myelosuppression and moderate nausea and vomiting. Cardiac toxicity was identified in three patients, with two patients demonstrating electrocardiogram (EKG) changes and arrhythmias and only one patient developing heart failure. The 24% overall response rate suggests no compromise in activity on this schedule, with a significant reduction in toxicity.

Phase II trial of mitoxantrone in multiple myeloma: a Southwest Oncology Group Study.

Thirty-five fully evaluable patients with advanced multiple myeloma, refractory to standard chemotherapeutic agents, were entered into a phase II trial with mitoxantrone at a starting dose of 12 mg/m2 iv every 3 weeks. There was one (3%) partial response (lasting 2 1/2 months) in a patient who had received treatment with five different agents, including doxorubicin (total dose, 150 mg/m2). Four additional patients (11%) showed objective evidence of clinical improvement, lasting 4-7 months. Mitoxantrone was well-tolerated with no drug-induced deaths and only moderate to severe leukopenia as the dose-limiting toxicity in the majority of patients. Although mitoxantrone had a low level of activity in this heavily pretreated patient population, consideration should be given to future trials incorporating mitoxantrone into a new drug combination.

Primary malignant pulmonary tumors in the older patient.

The incidence of lung cancer, the most common visceral malignancy, is increasing in the elderly patient. Careful preoperative preparation and postoperative care will allow some of these patients to have surgical resections. Radiotherapy and chemotherapy offer benefits for those patients who cannot have a curative surgical resection.

Long-term survival and toxicity in small cell lung cancer. Southwest Oncology Group study.

In the first study of combined chemotherapy and radiation therapy for small cell lung cancer by the Southwest Oncology Group, 17 patients survived more than five years after treatment was initiated (4.6 percent). Late relapse, or a second primary malignancy three to six years after diagnosis, accounted for death in five of these patients. Late recurrences involved the chest, bone, and liver; none occurred in the central nervous system. Disease-free survival continues in 10 patients (6 percent of those with limited disease and 1 percent of those with extensive-stage diseases) at a minimal follow-up in excess of six years. One definite case of chronic treatment-related toxicity occurred: congestive cardiomyopathy after 450 mg/m2 of doxorubicin, successfully managed with digitalis and diuretics. One severe neurologic problem (orthostatic hypotension with preterminal dementia) and two less severe neurologic complications (occasional falling episodes without documented cause and cerebrovascular accident) may be treatment-related. Progressive pulmonary disability, post-herpetic pain syndromes, organic brain syndrome, and hematologic abnormalities have not been observed to date. Nitrosourea administration and/or co-administration of a nitrosourea or methotrexate during the induction phase of treatment with radiotherapy to the brain may account for the higher incidence of complications observed by others in long-term survivors.

Addition of cisplatin and bleomycin to vincristine-carmustine-doxorubicin-prednisone (VBAP) combination in the treatment of relapsing or resistant multiple myeloma: a Southwest Oncology Group study.

Fifty-five patients with myeloma who had relapsed on or were resistant to melphalan and/or cyclophosphamide with prednisone received vincristine, carmustine, doxorubicin, and prednisone (VBAP) plus cisplatin and bleomycin at 21-day intervals. Eighteen (32.7%) patients responded. The response rate was 38.5% (15 responses among 39 patients) in relapsing patients. Three (18.8%) of 16 patients with resistant myeloma responded. Granulocytopenia was the most frequent toxic effect, and was severe in 12 (22%) patients. Severe thrombocytopenia occurred in seven (13%) patients and severe nausea and vomiting occurred in eight (15%). One patient with previously normal renal function developed renal failure on this regimen. The median survival (100 weeks) in those patients responding to treatment was significantly longer than that in patients not responding (25 weeks; P = 0.001). VBAP plus cisplatin and bleomycin was at least as effective as VBAP but had greater toxicity, expense, and inconvenience; it therefore is not preferable to VBAP.

Randomized trial of 5-fluorouracil and mitomycin C with or without streptozotocin for advanced pancreatic cancer. A Southwest Oncology Group study.

A prospective randomized trial comparing streptozotocin, mitomycin C, and 5-FU (SMF) with mitomycin C and 5-FU (MF) in patients with advanced pancreatic cancer was performed. In patients with measurable disease the response rates were 34% (19/56) to SMF, and 8% (5/60) to MF (P = 0.009). Median survivals were similar, however, 18 versus 17 weeks (P = 0.356). Median survival of patients responding to chemotherapy was 33 weeks, and for nonresponders it was 17 weeks (P = 0.002). In patients with nonmeasurable disease, median survivals were 21 weeks (SMF) and 18 weeks (MF) (P = 0.797). Patients surviving greater than or equal to 48 weeks, however, appeared to be increased in the SMF arm (14 patients) compared to the MF (7 patients). Toxicity was moderate for both regimens, with SMF having greater gastrointestinal and renal toxicity. Chemotherapy with SMF appears to produce objective responses in patients with pancreatic cancer, but does not improve survival compared to MF.