EMA Review of Isatuximab in Combination with Pomalidomide and Dexamethasone for the Treatment of Adult Patients with Relapsed and Refractory Multiple Myeloma

Isatuximab is a monoclonal antibody that binds to the human CD38 antigen. On May 30, 2020, a marketing authorization valid through the European Union (EU) was issued for isatuximab in combination with pomalidomide and dexamethasone (IsaPd) for the treatment of adult patients with relapsed and refractory (RR) multiple myeloma (MM). The recommended dose of isatuximab was 10 mg/kg, administered intravenously weekly at cycle 1 and then biweekly in subsequent 28-day cycles. Isatuximab was evaluated in a phase III, open-label, multicenter, randomized trial that randomly allocated IsaPd versus pomalidomide plus dexamethasone (Pd) to adult patients with RR MM. The primary endpoint of the trial was progression-free survival, as assessed by an independent review committee, which was superior for the IsaPd arm (hazard ratio, 0.596; 95% confidence interval, 0.436-0.814; p = .001) compared with the Pd arm. Treatment with IsaPd led to higher incidences of treatment-related adverse events (AEs), grade ≥ 3 AEs, and serious AEs compared with Pd treatment. Most frequently observed AEs that occurred more often in the IsaPd arm were infusion-related reactions, infections, respiratory AEs, neutropenia (including neutropenic complications), and thrombocytopenia. The aim of this article is to summarize the scientific review of the application leading to regulatory approval in the EU. IMPLICATIONS FOR PRACTICE: Isatuximab was approved in the European Union, in combination with pomalidomide and dexamethasone, for the treatment of patients with multiple myeloma who have already received therapy but whose disease did not respond or relapsed afterward. The addition of isatuximab resulted in a clinically meaningful and significant prolongation of the time from treatment initiation to further disease relapse or patient's death. The safety profile was considered acceptable, and the benefit-risk ratio was determined to be positive.

Midazolam inhibits neophobia-induced Fos expression in the rat hippocampus

The effect of midazolam on expression of c-Fos protein was examined in the rat hippocampus, following the open field test of neophobia. It was found that pretreatment of rats with midazolam, at the dose of 0.5 mg/kg, enhanced rat exploratory behavior, and inhibited neophobia related stimulation of c-Fos in the CA-1 and CA-3 areas of the hippocampus. The presented results provide new immunocytochemical data on the involvement of hippocampus in emotional processes related to neophobia, and indicate a possible site of action of benzodiazepines.

Pregnenolone sulfate potentiates the effects of NMDA on hippocampal alanine and dopamine

The aim of the present study was to analyze biochemical effects of a neurosteroid, pregnenolone sulfate (PS), which accompany changes in the threshold of seizures, and to establish the contribution of local, hippocampal monoaminergic and amino acid systems, to the control of convulsive activity. Pretreatment of mice with PS (intracerebroventricularly) selectively enhanced the potency of peripherally (intraperitoneally) administered NMDA at the LD16 (88.0 mg/kg) to induce clonic-tonic convulsions (PS, LD84 = 184.7 nM; 95% CL = 181.4-188.1). The proconvulsive actions of picrotoxin and bicuculline, the GABA-A receptor antagonists, were not modified by pretreatment of mice with PS. Administration of PS alone (up to 240 nM icv) did not show any seizure-like activity. PS given at LD84, together with NMDA (at the LD16), increased the hippocampal concentration of alanine, and enhanced local metabolism of dopamine in a period immediately preceding the onset of seizures significantly stronger than did NMDA alone. These and other data indicate that the enhancement by PS of hippocampal levels of alanine may contribute to the seizures development as this amino acid is a precursor of glutamate, and a co-agonist of the NMDA receptors. On the other hand, simultaneously occurring stimulation of hippocampal dopaminergic system may be considered a compensatory phenomenon, limiting seizures propagation through the limbic forebrain. Summarizing, our results show that PS-induced potentiation of NMDA seizures is accompanied by selective changes in hippocampal dopamine turnover and alanine concentration.

Pentylenetetrazol-kindling of seizures selectively decreases [3H]-citalopram binding in the CA-3 area of rat hippocampus

The present study was aimed at determining the changes in the 5-HT transporter activity, in different brain structures after pentylenetetrazol induced kindling of seizures. We examined [3H]-citalopram binding in the rat brain structures, and the neurodegenerative effects in the hippocampal formation using autoradiographic and immunohistochemical methods. A statistically significant and selective reduction in the binding of [3H]-citalopram was found in the CA3 field of the hippocampus (P=0.009), and a similar tendency, close to the significance level, in the dentate gyrus (P=0.05). This effect was accompanied by a loss of neurons and activation of microglia in the hippocampal formation. The present data suggest the important role for CA3- serotonergic innervation in pentylenetetrazol induced kindling of seizures.