Treatment of alkylating resistant multiple myeloma with vincristine, BCNU, doxorubicin and prednisone (VBAP)

Gemcitabine alone or combined with cisplatin in relapsed or refractory multiple myeloma

Gemcitabine is a pyrimidine nucleoside analog with antitumor activity against solid tumor malignancies and leukemia. We evaluated its activity as a single agent and combining it with cisplatin in relapsed-refractory multiple myeloma (MM). Sixteen patients with advanced MM received intravenous gemcitabine 1250 mg/mq (days 1, 8 and 15) as a single agent for a total of 3 monthly courses. The responders received another three courses, and the non-responders received three courses of gemcitabine 1000 mg/mq (days 1, 8 and 15) plus cisplatin 80 mg/mq (day 1). No grade 4 hematological toxicity was seen after gemcitabine treatment, whereas > or = 3 grade neutropenia and thrombocytopenia were seen in 21 and 13% of the gemcitabine-cisplatin infusions, respectively. Non-hematological toxicity was negligible for both the regimens. After three courses of gemcitabine as a single agent, th e response rate was 31% (1 complete response, 1 partial response and 3 minimal response). Eight patients (50%) achieved stable disease and 3 (19%) had disease progression. Ten patients received gemcitabine-cisplatin and were evaluable for the response. Two patients progressed, four maintained stable disease whereas four patients, unresponsive to gemcitabine, obtained a response (3 partial response and 1 minimal response). With a median follow-up of 13 months (range 8-17.5), 7 patients (44%) died, 5 (31%) had disease progression, 1 (6%) relapsed, 1 was still in partial response (+11 months) and 2 (13%) had a stable disease. Median time to treatment failure (TTF) was 8 months (CI95%: 7.6-8.4) and median overall survival (OS) was 16 months (CI95%: 10-22). These results showed that gemcitabine and gemcitabine-cisplatin were feasible regimens and well tolerated in advanced relapsed-refractory MM. The response rates, the TTF and OS were similar to other salvage chemotherapy regimens; nevertheless, the quality of response was modest particularly after gemcitabine alone. Better results might be obtained combining gemcitabine with other chemotherapy compounds or with biologically based therapies.

Treatment approaches for relapsing and refractory multiple myeloma

Relapsing patients with multiple myeloma show a response rate higher than 50% with the resumption of the initial chemotherapy. However, since the duration of second responses are short, HDT/autotransplantation is recommended in patients with sensitive relapse. In patients with primary refractory myeloma the best treatment approach seems to be early HDT/autotransplantation. It is crucial to recognize a subset of patients who do not respond to the initial chemotherapy but who have non-progressive disease in order to avoid the administration of salvage regimens until clinical disease progression occurs. The treatment of patients with refractory relapse is disappointing. The most promising agent in this situation is thalidomide. Patients with late relapse after autologous transplantation can benefit from a second autologous transplant. The results of the allogeneic transplantation after autotransplantation are disappointing. In heavily pretreated resistant patients a conservative approach with alternate day prednisone (30 to 50 mg) along with pulse cyclophosphamide (800 to 1,200 mg every 2 to 3 weeks) is recommended.

Treatment of melphalan-resistant multiple myeloma with vincristine, BCNU, doxorubicin, and high-dose dexamethasone (VBAD)

A total of 65 patients (35 male/30 female) with multiple myeloma primarily (33) or secondarily (32) resistant to melphalan and prednisone were treated with vincristine, carmustine (BCNU), doxorubicin, and high-dose dexamethasone (VBAD) at 4-week intervals. Among 60 evaluable patients the overall response was 36.6% (21.6% objective response plus 15% improvements). The response rate was significantly higher in primarily resistant patients than in those becoming resistant after a prior response (48.4 vs. 24.1%, P < 0.05). The median duration of response was 17.5 months. When survival of responders and non-responders were compared by the conventional method, a highly significant difference was observed (P < 0.001). However, using the Mantel and Byar procedure and the landmark method, only a trend for longer survival in the responders was registered. These results indicate that although VBAD is effective in at least one third of patients with advanced multiple myeloma resistant to melphalan, its impact on survival is limited.

The clinical pharmacology and use of antimicrotubule agents in cancer chemotherapeutics

Although there has been a rapid expansion of the number of classes of compounds with antineoplastic activity, few have played a more vital role in the curative and palliative treatment of cancers than the antimicrotubule agents. Although the vinca alkaloids have been the only subclass of antimicrotubule agents that have had broad experimental and clinical applications in oncologic therapeutics over the last several decades, the taxanes, led by the prototypic agent taxol, are emerging as another very active class of antimicrotubule agents. After briefly reviewing the mechanisms of antineoplastic action and resistance, this article comprehensively reviews the clinical pharmacology, therapeutic applications, and clinical toxicities of selected antimicrotubule agents.