Phase 2 Trial of Concurrent Monosialotetrahexosylganglioside in the Prophylactic Treatment of Bortezomib-Induced Peripheral Neuropathy in Patients of Multiple Myeloma

Backgrounds

Bortezomib is an important drug in the treatment of multiple myeloma (MM), and peripheral neuropathy (PN) is a significant dose-limiting toxicity of bortezomib. No effective prophylaxis has been defined for PN. Monosialotetrahexosylganglioside (GM), a nerve-protecting drug, is often used to promote growth of nerve and function restoration of damaged nerve. The role of GM in the prophylaxis of bortezomib-induced PN in MM patients has never been investigated.

Methods

A phase 2 clinical trial was conducted in newly diagnosed MM patients to evaluate the value of GM in the prophylaxis of bortezomib-induced PN. All eligible patients were treated with VD (bortezomib 1.3mg/㎡,subcutaneous injection, d1 ,8,15,22, and dexamethasone 40mg, po,d1 ,8,15,22, 4 weeks a cycle) or CyBorD (cyclophosphamide 300mg/㎡,po,d1 ,8,15, bortezomib 1.3mg/㎡,subcutaneous injection, d1 ,8,1 5,22, and dexamethasone 40mg, po,d1 ,8,15,22, 4 weeks a cycle) for at least 4 cycles. GM was used at a dosage of 100mg/day intravenously at d1 -2, 8-9, 15-16, 22-23. No other nerve-protective drugs or thalidomide-containing regimens were allowed. The primary endpoint was overall incidence rate of PN (the grade of PN was recorded according to CTCAE v3.0). The secondary endpoints included duration of PN, complete response rate after 4 cycles of treatment, 1-year PFS and OS rate. (This trial was registered in ClinicalTrial.gov, NCT02093910).

Results

From February 2014 to February 2015, 25 patients of newly diagnosed MM were enrolled. The median age was 55 years old (37-75), and male to female ratio was 19:6. 5 patients had ISS stage I disease, 6 patients with stage II, and the remaining 14 patients with stage III. All patients received a median of 4 cycles (range 2-9) of Bortezomibcontaining regimens. At the time of data analysis, 84% of patients had at least partial response, 48% had at least very good partial response, and 24% had complete response. 7 patients experienced PN after a median of 2 cycles (range 1-4) of treatment, resulting in the overall PN rate of 28%. Among these 7 patients, only 1 patient (4%) had grade 2 PN, leading to dose reduction of bortezomib, and all other patients had grade 1 PN. During treatment, 1 patient (4%) had grade 2 diarrhea, and another 1 patient (4%) had herpes zoster infection. The concurrent use of GM did not introduce new side effects and seemed not compromise the efficacy of bortezomib. At a median follow up time of 8 months, 1-year PFS rate and OS rate were speculated to be 69.8% and 100%, respectively.

Conclusions

The early-term analysis of this phase 2 trial found it feasible to concurrently use GM and bortezomib-containing regimens, and GM had the potential role of reducing bortezomib-induced PN rate and severity without compromising efficacy. This needs to be validated in future phase 3 randomized clinical trials.