Therapeutic implications of myeloma staging

Percutaneous cementoplasty in multiple myeloma: a valuable adjunct for pain control and ambulation maintenance

GOALS OF WORK

Bone pain and functional impairment are major concerns for multiple myeloma (MM) patients. The goal of this study was to better define the role of percutaneous cementoplasty (PC) in improving their quality of life.

MATERIALS AND METHODS

This retrospective analysis included 28 consecutive heavily pretreated MM patients managed at our institution between 1996 and 2002. They underwent a total of 34 PC procedures for the treatment of 117 vertebrae and 2 iliac sites and were evaluated at 1 month.

MAIN RESULTS

Significant pain reduction of >50% was obtained after 83% of the procedures, with a mean visual analogous score decreasing from 7.48/10 to 2.1/10 (p < 0.001). It resulted in a complete interruption of opiate analgesic consumption after 59.3% of the procedures, with a mean decrease of 70.4% in the opiate dose. Functional impairment was evaluated with the Eastern Cooperative Oncology Group (ECOG) performance status scale, with mean scores improving from 1.9 to 0.86 after the procedures (p = 0.001). There was no major complication.

CONCLUSION

PC is a safe, feasible, and efficient approach for the treatment of bone pain and disability in MM patients.

Development of 17-allylamino-17-demethoxygeldanamycin hydroquinone hydrochloride (IPI-504), an anti-cancer agent directed against Hsp90

Heat shock protein 90 (Hsp90) is an emerging therapeutic target of interest for the treatment of cancer. Its role in protein homeostasis and the selective chaperoning of key signaling proteins in cancer survival and proliferation pathways has made it an attractive target of small molecule therapeutic intervention. 17-Allylamino-17-demethoxygeldanamycin (17-AAG), the most studied agent directed against Hsp90, suffers from poor physical-chemical properties that limit its clinical potential. Therefore, there exists a need for novel, patient-friendly Hsp90-directed agents for clinical investigation. IPI-504, the highly soluble hydroquinone hydrochloride derivative of 17-AAG, was synthesized as an Hsp90 inhibitor with favorable pharmaceutical properties. Its biochemical and biological activity was profiled in an Hsp90-binding assay, as well as in cancer-cell assays. Furthermore, the metabolic profile of IPI-504 was compared with that of 17-AAG, a geldanamycin analog currently in clinical trials. The anti-tumor activity of IPI-504 was tested as both a single agent as well as in combination with bortezomib in myeloma cell lines and in vivo xenograft models, and the retention of IPI-504 in tumor tissue was determined. In conclusion, IPI-504, a potent inhibitor of Hsp90, is efficacious in cellular and animal models of myeloma. It is synergistically efficacious with the proteasome inhibitor bortezomib and is preferentially retained in tumor tissues relative to plasma. Importantly, it was observed that IPI-504 interconverts with the known agent 17-AAG in vitro and in vivo via an oxidation-reduction equilibrium, and we demonstrate that IPI-504 is the slightly more potent inhibitor of Hsp90.

Magnitude of response with myeloma frontline therapy does not predict outcome: importance of time to progression in southwest oncology group chemotherapy trials

PURPOSE

Four Southwest Oncology Group (SWOG) standard-dose chemotherapy protocols for multiple myeloma (MM) initiated between 1982 and 1992 were evaluated. The purpose was to clarify the predictive value of specific levels of myeloma-associated monoclonal protein reduction and time to first progression using mature data sets.

PATIENTS AND METHODS

Study data on 1,555 eligible previously untreated patients with MM enrolled onto SWOG phase III trials 8229, 8624, 9028, and 9210 were used in these analyses. Six-month and 12-month landmark analyses were performed to evaluate the outcome for patients in each response category.

RESULTS

The overall and event-free survivals for the four protocols combined were 33 months and 18 months, respectively. Using 6- and 12-month landmarks, the median survivals of 30 to 35 months were not different for responders (> or = 50% and > or = 75% regression) versus nonresponders in patients without disease progression before the landmarks. Conversely, at the 6- and 12-month landmarks, the median survivals for patients who had experienced disease progression were 13 and 15 months, respectively, versus a 34-month median for patients who did not experience progression. Using the Cox survival model, with response and progression considered as time-dependent covariates, survival duration was influenced more by the occurrence of progression than by the occurrence of response.

CONCLUSION

The magnitude of response, as a single variable, does not predict survival duration. Patients with response and stable disease have equivalent outcome. Only patients with progressive disease have a poorer outcome. The best indicator of survival is time to first progression.