In clinical trials, patients with pre-existing neuropathy greater than Grade 2 were excluded. However, patients with pre-existing neuropathy Grade 1 or 2 were no more likely to develop new or worsening symptoms than those who entered the study without the condition.

QT prolongation

In an uncontrolled open-label ECG study in 26 patients, QT prolongation was observed on Day 8, independent of eribulin concentration, with no QT prolongation observed on Day 1. ECG monitoring is recommended if therapy is initiated in patients with congestive heart failure, bradyarrhythmias or concomitant treatment with medicinal products known to prolong the QT interval, including Class Ia and III antiarrhythmics, and electrolyte abnormalities. Hypokalemia or hypomagnesemia should be corrected prior to initiating HALAVEN and these electrolytes should be monitored periodically during therapy. Eribulin should be avoided in patients with congenital long QT syndrome.

Use in combination with anti-HER2 therapy

There is no experience of using eribulin in combination with anti-HER2 therapy in clinical trials.

Excipients

This medicinal product contains small amounts of ethanol (alcohol), less than 100 mg per dose.

4.5 Interaction with other medicinal products and other forms of interaction
Eribulin is mainly (up to 70%) eliminated through biliary excretion. The transport protein involved in this process is unknown. Complete inhibition of the transport could in theory give rise to a more than 3-fold increase in plasma concentrations. It is not recommended to use substances which are inhibitors of hepatic transport proteins such as organic anion-transporting proteins (OATPs) and multidrug resistant proteins (MRPs) etc concomitantly with eribulin. Inhibitors of such transporters include but are not limited to: cyclosporine, ritonavir, saquinavir, lopinavir and certain other protease inhibitors, efavirenz, emtricitabine, quinine, quinidine, disopyramide etc.

It cannot be excluded that concomitant treatment with inducing substances, such as carbamazepine, phenytoin, St John´s wort (Hypericum perforatum), could give rise to reduced plasma concentrations of eribulin, and co-administration with inducers should be carried out with caution considering a potential risk for reduced drug efficacy. No marked effects on eribulin exposure (AUC and Cmax) were observed during treatment with the CYP3A4 inducer rifampicin. However, rifampicin may due to its transporter inhibitory property counteract its possible inducing effect on eribulin elimination. Therefore, the effect of rifampicin may not presently be extrapolated to other inducers.

No drug-drug interactions are expected with CYP3A4 inhibitors. Eribulin exposure (AUC and Cmax) was unaffected by ketoconazole, a CYP3A4 and P glycoprotein (Pgp) inhibitor.

Effects of eribulin on the pharmacokinetics of other drugs

In vitro data indicate that eribulin is a mild inhibitor of the important drug metabolising enzyme CYP3A4. No in vivo data are available. Caution and monitoring for adverse effects is recommended with concomitant use of substances that have a narrow therapeutic window and that are eliminated mainly via CYP3A4-mediated metabolism (e.g. alfentanil, cyclosporine, ergotamine, fentanyl, pimozide, quinidine, sirolimus, tacrolimus).

Eribulin does not inhibit the CYP enzymes CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6 or 2E1 at relevant clinica