Tolerance, Kinetics, and Depth of Response for Subcutaneous Versus Intravenous Administration of Bortezomib Combination in Chinese Patients With Newly Diagnosed Multiple Myeloma.

BACKGROUND

Peripheral neuropathy (PN) is an important toxicity that limits the use of bortezomib (Btz). Attempts to reduce PN have included its subcutaneous (SC) administration.

PATIENTS AND METHODS

We retrospectively analyzed 307 patients with newly diagnosed multiple myeloma from a single Chinese center, receiving Btz-based regimens administered either via SC injection (SC group, n = 167) or intravenous (IV) infusion (IV group, n = 140). The efficacy and safety of Btz administration via SC and IV were then compared.

RESULTS

Most baseline characteristics were similar between these 2 groups. A lower frequency of adverse events, especially grade ≥ 3 PN (P = .002), was observed in the SC group compared with the IV group. The estimated median Btz dosage when PN developed was higher (20.8 mg/m vs. 15.6 mg/m), and fewer patients reduced or discontinued Btz owing to adverse events in the SC group compared with the IV group. The overall response rate (≥ partial response [PR]) was comparable (94.8% vs. 96.2%). However, patients in the IV group required fewer cycles to achieve PR, whereas a larger proportion of patients in the IV group achieved ≥ very good PR. After a median follow-up of 23 months (range, 1-84 months), no significant difference in median progression-free survival (not arrived vs. 33.0 ± 2.735 months) and overall survival (not arrived vs. 56.0 months) was noted.

CONCLUSION

SC Btz is associated with better tolerance; however, IV administration achieves a faster and deeper response in Chinese patients with newly-diagnosed multiple myeloma.