399P - Role of denosumab as targeted therapy in treatment of unresectable or recurrent cases of giant cell tumor of the bone

Background

The primary modality of treatment of Giant cell tumor of bone (GCTB) is surgical resection; which is not always possible given the location and extent of the neoplasm. A recent phase II data have demonstrated denosumab's (RANKL inhibitor) activity concerning disease and symptom control, without significant adverse effects.

Methods

This was the retrospective study done at our institute to evaluate the efficacy of preoperative Denosumab in unresectable or recurrent cases of GCTB. A total of 14 patients with unresectable GCT of different parts of the body were selected with 7 patients in each group. In one group patients were treated with preoperative denosumab at least 6 weeks before surgery between January 2017- December 2020 and in the control group just the extended curettage was done. The clinical, radiological, and pathological alterations after the denosumab treatment were compared and adverse effects or complications of denosumab were reported.

Results

The pain got relieved in all 7 patients after the 2nd/ 3rd injection of denosumab in the case group. The neurology improved after 3doses in spine patients. Incidence of pathological fracture decreased to 5% which was 26% in the control group seen throughout the Median follow-up time of 36 months. Only 1 patient got recurrence in the case group, treated with en bloc resection. No adverse effects or complications were seen.

Conclusions

Denosumab has proved to be a useful targeted therapy for unresectable or recurrent GCTB cases. Short-term (six doses) preoperative use of denosumab improved clinical symptoms, decreased the tumor size, and subsequently, decreased the local recurrence while its long-term safety profile is still unknown.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

The authors.

Funding

Has not received any funding.

Disclosure

All authors have declared no conflicts of interest.