Robert E. Wittes

A reevaluation of nonhormonal cytotoxic chemotherapy in the treatment of prostatic carcinoma.

The palliative role of nonhormonal cytotoxic chemotherapy in the treatment of endocrine-resistant prostatic carcinoma has not been established. Conventional means of quantifying tumor response are most frequently not applicable in this disease because of the lack of measurable objective parameters to allow for a reliable estimation of antitumor effects. While this problem is not unique to prostatic carcinoma, this review illustrates its magnitude in this disease. Only approximately 5% of patients studied fulfill the various criteria for complete response (CR), partial response (PR), or both, while the vast majority of patients reported as responders are actually in the stable disease category. Stable disease is highly questionable as an indicator of antitumor response and should not be used as a criterion for response in conventional phase II studies unless it is convincingly demonstrated that it occurs as a result of treatment. A study design that may allow a more reliable assessment of the value of the stable disease category is described in the text. More effective means for assessing tumor responses and better instruments to measure aspects of quality of life are needed. Review of several prospective randomized clinical trials showed that no treatment program tested during the last decade resulted in a survival advantage when compared with a concurrently treated control group. Furthermore, in two such trials, four different single chemotherapeutic agents widely used in the treatment of this disease (cyclophosphamide, 5-fluorouracil, estramustine phosphate, and streptozocin) either alone or in combination, did not produce any prolongation of survival when compared to a no chemotherapy (standard treatment) control arm. Survival curves for endocrine-resistant patients fall within a relatively narrow and possibly predictable range that may be used as an additional endpoint in conjunction with response (CRs and PRs only) in phase II trials. More definitive evidence of therapeutic efficacy in this disease should derive from phase III trials using survival as one of the major endpoints. Because of the poor results observed with chemotherapy thus far, we suggest that the appropriate control arm for phase III testing in endocrine-resistant patients continues to be a no chemotherapy control arm consisting of a best symptomatic care or a uniformly applied second-line endocrine manipulation.

Phase II trial of chemotherapy alone for primary CNS and intraocular lymphoma.

PURPOSE Primary CNS lymphoma (PCNSL) and primary intraocular lymphoma (IOL) are usually treated with radiation therapy alone or in combination with chemotherapy. The neurotoxicity of these treatments can be substantial. This study attempts to define the toxicity and efficacy of the treatment of this disease with chemotherapy alone. PATIENTS AND METHODS Fourteen nonimmunocompromised patients were accrued to a chemotherapy regimen that incorporated a 24-hour infusion of high-dose methotrexate total dose of 8.4 g/m2 with leucovorin rescue; thiotepa 35 mg/m2; vincristine 1.4 mg/m2; dexamethasone; and intrathecal cytarabine (Ara-C) and methotrexate (MTV) administered in 21-day cycles. Seven patients were prospectively followed up with formal neuropsychologic assessments for evidence of CNS toxicity. RESULTS The response rate was 100% with 11 (79%) complete responses and three (21%) partial responses. Cumulative survival and progression-free survival rates at more than 4.5 years were 68.8% and 34.3%, respectively. Median survival has not been reached, and median progression-free survival was 16.5 months. Toxicity included severe leukoencephalopathy that was clearly attributable to chemotherapy (two patients), grade 3 or 4 neutropenia in 50% of the cycles administered, ileus (one patient), and seizures (two patients). Mucositis and renal and hepatic toxicity were mild and not therapy limiting. CONCLUSION The MTV regimen is generally well tolerated and produces a high complete response rate. Chemotherapy alone should be investigated further in this disease to assess the necessity of initial radiation therapy, either alone or in combined modality regimens, for the achievement of optimal response and survival.

Paclitaxel in doxorubicin-refractory or mitoxantrone-refractory breast cancer: a phase I/II trial of 96-hour infusion.

PURPOSE A phase I study of paclitaxel infused over 96-hours was performed to determine toxicity, maximum-tolerated dose (MTD), and pharmacokinetics in patients with incurable lymphomas and solid tumors. A phase II study was performed at the MTD of paclitaxel in patients with doxorubicin/mitoxantrone-refractory metastatic breast cancer. PATIENTS AND METHODS In the phase I study, paclitaxel dose levels ranged from 120 to 160 mg/m2, administered on a 21-day cycle. Patients with metastatic breast cancer who had either no response or a partial response (PR) to doxorubicin or mitoxantrone and had measurable disease were eligible for the phase I and II studies. Expression of the multidrug resistance (mdr-1) gene was determined in tumor biopsies by mRNA quantitative polymerase chain reaction. RESULTS Twelve patients received a total of 73 cycles of paclitaxel on the phase I study. Dose-limiting mucositis and/or grade IV granulocytopenia was reached at 160 mg/m2, and 140 mg/m2 was selected as the phase II dose. Thirty-six consecutive patients with metastatic breast cancer were treated, of whom three were not assessable. The median age was 49 years, with disease in the liver and/or lung in 76%. Patients received a median of two prior regimens for metastatic disease, and 73% had no response to prior doxorubicin or mitoxantrone. Of 33 patients treated with paclitaxel, 16 patients (48%) achieved a PR and five (15%) achieved a minor response (MR). With a median potential follow-up duration of 60 weeks, the median progression-free and overall survival durations were 27 and 43 weeks, respectively. No correlation was found between extent of prior treatment or prior response to doxorubicin/mitoxantrone, and response to paclitaxel. Paclitaxel pharmacokinetics showed a correlation between both granulocyte and mucosal toxicity, and serum steady-state concentrations (Css) more than 0.07 mumol/L. Patients with liver metastases had significantly decreased paclitaxel clearance and higher paclitaxel Css. Levels of mdr-1 were uniformly low in all tumor biopsies studied. CONCLUSION The recommended phase II dose of paclitaxel is 140 mg/m2 in patients without liver metastases and 105 mg/m2 in patients with liver metastases. Ninety-six-hour infusions of paclitaxel were effective and well tolerated in patients with doxorubicin/mitoxantrone-refractory breast cancer. Prolonged infusion schedules may be more effective than shorter schedules and deserve further study.

EPOCH chemotherapy: toxicity and efficacy in relapsed and refractory non-Hodgkin's lymphoma.

PURPOSE Based on in vitro evidence that tumor cells are less resistant to prolonged exposure to low concentrations of the natural product class, compared with brief higher concentration exposure, we developed a chemotherapy regimen (etoposide, vincristine, doxorubicin, cyclophosphamide, and prednisone [EPOCH]) in which the natural products are administered as a continuous infusion. PATIENTS AND METHODS This is a phase II study of etoposide, vincristine, and doxorubicin, administered as a 96-hour continuous infusion, with intravenous (IV) bolus cyclophosphamide and oral prednisone (EPOCH) in 74 consecutive patients who relapsed from or failed to respond to most of the same drugs administered on a bolus schedule. Patients with aggressive lymphomas who achieved a good response after EPOCH were eligible to undergo bone marrow transplantation. RESULTS Patients with intermediate- or high-grade lymphoma comprised 76% of this series and 77% had stage IV disease. Seventy-one percent had previously received all of the drugs contained in the EPOCH regimen and 92% had received at least four of the drugs. Seventy patients were assessable for response, of whom 19 (27%) achieved a complete remission (CR) and 42 (60%) a partial remission (PR). Among 21 patients who had no response to prior chemotherapy, 15 (71%) responded, but only one achieved a CR. Patients who relapsed from an initial CR had a 100% response rate, with 76% CRs. With a median potential follow-up duration of 19 months, there was a 28% probability of being event-free at 1 year. Toxicity was primarily hematologic with neutropenia during 51% of cycles, but only a 17% incidence of febrile neutropenia. Gastrointestinal, neurologic, and cardiac toxicity were minimal. CONCLUSION EPOCH chemotherapy was well tolerated and highly effective in patients who were resistant to or relapsed from the same drugs administered on a bolus schedule, suggesting that continuous infusion of the natural drug component of this regimen is capable of partially reversing drug resistance and reducing toxicity. Dose-intensity (DI) was > or = that achieved in primary treatment regimens for aggressive lymphomas.

Combination therapy of advanced head and neck cancer. Induction of remissions with diamminedichloroplatinum (II), bleomycin and radiation therapy

Patients with unresectable, previously untreated head and neck cancer were given cis‐diamminedichloroplatinum (II) (DDP), 3 mg/kg, with mannitol diuresis (day 1), followed by a continuous infusion of bleomycin, 0.25 mg/kg/day, days 3 through 10, after an initial loading dose of 0.25 mg/kg by rapid IV injection on day 3. The DDP was repeated on day 22, following which radiotherapy was delivered using standard doses, fractionations and portals. Patients were evaluated for response on day 22 and again at the conclusion of radiotherapy. Of 21 patients evaluable at day 22, there were four CR and 11 PR (>50% reduction of all measurable disease), for a major response rate of 71%. Of five MR, four showed 30–60% reduction at the primary site. Of 16 who have finished the radiation phase of treatment, there are six CR, five PR and one MR with durations four to eight months. Toxicity in 33 patients included vomiting (33), alopecia (33), WBC < 3000 (five), platelets lt; 100,000 (one), dose‐limiting mucositis during bleomycin (six) and peak serum creatinine > 2 (five), with one fatality. The regimen thus appears promising as initial therapy for the previously untreated patient. The same chemotherapy has produced much less encouraging results in previously treated patients.

The evolution of mature teratoma from malignant testicular tumors.

During the period 1969‐1976 twelve cases of malignant germ cell tumor of the testis were seen in which the diagnosis was associated with the subsequent development of one or more metastases composed histologically of fully mature teratoma. These patients had a variety of primary germ cell tumors in the testis and were treated with radiation therapy and/or chemotherapy in addition to surgery, prior to the development of mature teratomas in different anatomic sites. The development of mature teratoma in this clinical setting seems to be a favorable prognostic sign, inasmuch as only one of the 12 patients has died with known persistent cancer. Since the incidence of this phenomenon seems to be increasing, the mechanism is probably related, directly or indirectly, to therapy. Cancer 40:2987‐2992, 1977.

Autologous bone marrow transplantation. Current status and future directions.

PURPOSE To assess the current status of high-dose chemotherapy with autologous marrow transplantation in hematologic malignancies and solid tumors. DATA IDENTIFICATION Studies reported between 1978 and May 1988 were identified through computer searches using Medline and Cancerline and through extensive manual searching of bibliographies of identified books and articles. STUDY SELECTION More than 160 studies that contained adequate response, toxicity, or survival data were selected for analysis, including peer-reviewed articles, book chapters, and proceedings of meetings. The most current or complete references were used for series reported more than once. DATA ANALYSIS Information abstracted included regimen used, number of patients, response rates, disease-free and overall survival, and toxicities. A meta-analysis of the pooled data was done. RESULTS OF DATA ANALYSIS For many tumor types, autologous marrow transplantation offers higher response rates than standard approaches. For leukemias and lymphomas, response rates of 60% to 80% may be achieved with the potential for cure. With solid tumors, response rates range from 30% in gliomas, 50% in melanomas and colon cancer, more than 60% in lung cancer, and 80% in breast cancer. Although responses tend to be short-lived, long-term survival can occasionally be seen. CONCLUSIONS Results with autologous marrow transplantation can be improved through systematically developed, carefully designed clinical trials that may be facilitated by collaborative research. Studies should focus on disease-directed drug combinations, several courses of high-dose therapy, treatment at a time of lower tumor burden, and reducing toxicity with hematopoietic growth factors.

Controlled trial of dexverapamil, a modulator of multidrug resistance, in lymphomas refractory to EPOCH chemotherapy.

PURPOSE Overexpression of the multidrug resistance gene (mdr-1) is present in up to 60% of relapsed lymphomas. To study its role in lymphomas, we conducted a controlled trial of dexverapamil, an inhibitor of the mdr-1 gene product, P-glycoprotein (Pgp), in lymphomas refractory to etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin (EPOCH) chemotherapy. PATIENTS AND METHODS Eligible patients had recurrent Hodgkins (HD) or non-Hodgkins lymphomas (NHL) and measurable disease. Patients initially received EPOCH alone and those with stable tumor over two cycles or progressive disease crossed over to receive dexverapamil and EPOCH on subsequent cycles. Dexverapamil was escalated eight dose levels, from 240 to 1,200 mg/m2/d. When possible, serial biopsies were obtained to measure mdr-1 expression by quantitative polymerase chain reaction (PCR). RESULTS Of 154 patients entered onto the trial, 109 had NHL and 45 had HD. The median age was 44 years, 67% had stage IV disease, and the median number of prior regimens was two (range, one to 12) in NHL and one (range, one to four) in HD. Sixty-four patients (42%) crossed over, of which eight were not assessable. The maximum-tolerated dose of dexverapamil was 900 mg/m2/d. Among 41 NHL patients (excluding mycosis fungoides), there were three complete responses (CRs) and two partial responses (PRs) (12%) and five minor responses (MRs); two of 10 HD patients achieved PRs. The mdr-1 level was measured in 44 biopsies from 19 patients. Pretherapy, mdr-1 was low (median, 2.5 U) but increased (median, 12.2 U) at crossover. Of six patients with mdr-1 levels greater than 15 U, three responded to dexverapamil, while only one of eight patients with mdr-1 levels less than 15 U responded. EPOCH and dexverapamil were well tolerated, but compared with EPOCH alone, produced more hematologic toxicity. CONCLUSION These results suggest that Pgp plays a role in clinical drug resistance of lymphomas. However, they also suggest that mechanisms other than Pgp are prominent in heavily pretreated patients and that, although Pgp inhibition may be necessary, it is probably insufficient. Earlier intervention with dexverapamil may be more effective and warrants further study.

Commentary concerning demonstration of safety and efficacy of investigational anticancer agents in clinical trials.

Expeditious clinical development and approval of new drugs that are beneficial to patients are matters of high priority. There has been a great deal of discussion within the oncology community about what should constitute evidence of effectiveness of new anticancer agents for purposes of drug approval. This commentary is intended to illustrate a variety of end points that can lead to approval of new anticancer agents for specific clinical situations. Although the ultimate hope of antineoplastic therapy is prolongation of life, there are other effects of anticancer drugs that constitute clear clinical benefit and represent evidence of effectiveness. The guiding principle is that the beneficial effects obtained from a new drug should sufficiently outweigh the adverse effects such that the potential risk:benefit ratio achieved by an individual patient is favorable. The assessment of a new drug should flexibly evaluate safety and efficacy in the context of the specific clinical condition being treated. Early discussions with the Food and Drug Administration (FDA) and the National Cancer Institute (NCI) are recommended to identify prospectively the end points and trial designs needed to demonstrate effectiveness of a new drug. The general principles discussed will likely apply to the drug approval process for other medical disciplines as well.

Germ cell tumors (II): VAB II in metastatic testicular cancer.

Between June 1974 and January 1976, 50 patients with metastatic nonseminometous testicular carcinoma were treated with the V AB II protocol. The induction phase consisted of vinblastine (0.4 mg/kg) and actinomycin D (0.02 mg/kg) on day 1. Bleomycin (0.5 mg/kg) was given by continuous infusion for 7 days, and cis‐diammine‐dichloroplatinum (II) (DDP) (1 mg/kg) was given on day 8. A weekly maintenance of vinblastine and bleomycin, with actinomycin D and DDP on a rotating schedule was given followed by vinblastine, actinomycin D and chlorambucil every 3–4 weeks. Therapy was discontinued after 30–36 months of treatment in the face of continued remission. The response rate was 50% CR, 34% PR with 60% CR and 36% PR in previously untreated patients. Second‐look surgery and excision of residual lesions was performed in selected cases. Alopecia, mucositis, nausea, and vomiting were universal. One patient died in the postsurgical period of toxicity from the combination of bleomycin and high concentrations of oxygen. There were seven instances of allergic reactions to DDP. Eleven of 25 complete responders and 4 partial or minor responders who underwent excision of stable disease remain alive from 19 to 35 months following start of therapy, 12 of them without evidence of disease. Cancer 42:2162–2168, 1978.