Panobinostat, in combination with bortezomib and dexamethasone, can be used in patients who have already received at least two prior treatments including bortezomib and an immunomodulator. It is taken as capsules once daily on days 1, 3, 5, 8, 10 and 12 of a 21-day cycle, starting at a dose of 20mg.
Inhibition of histone deacetylase by panobinostat, leads to increased acetylation of histones, the proteins around which DNA is coiled to form a complex called chromatin. This acetylation results in relaxation of chromatin, which is thought to activate the transcription of tumour suppressor genes involved in cell cycle arrest and apoptosis.
Approval of panobinostat was based on the results of a randomised, double-blind phase III trial (PANORAMA 1) in patients with relapsed or refractory multiple myeloma who had received one to three previous treatment regimens.
Median progression-free survival, the primary endpoint, was significantly longer in patients treated with panobinostat than in those who received placebo, at 11.99 months (95% CI 10.33–12.94) versus 8.08 months (95% CI 7.56–9.23; hazard ratio 0.63, 95% CI 0.52–0.76; p<0.0001).
Diarrhoea and cardiac toxicity
Serious adverse events were reported in 60% of patients in the panobinostat group and 42% of patients in the placebo group. Common grade 3–4 laboratory abnormalities and adverse events included thrombocytopenia (67% in the panobinostat group vs 31% in the placebo group), lymphopenia (53% vs 40%), diarrhoea (26% vs 8%), asthenia or fatigue (24% vs 12%), and peripheral neuropathy (18% vs 15%).
Blood counts, fluid and electrolyte levels, and liver function must be monitored frequently in patients taking panobinostat and prescribers should be aware of the increased risks of bleeding and infection. Panobinostat may prolong the QT interval and caution is required when it is used in patients with pre-existing QT prolongation or relevant risk factors.
Women of childbearing potential should ensure they use contraception during and for 3 months after stopping treatment with panobinostat.
NICE recommends panobinostat as an option for treating relapsed and/or refractory multiple myeloma in line with its marketing authorisation. Approval is contingent on the company providing the drug with the discount agreed in the patient access scheme.