Sun Pharma's proposal to amend CT protocol for pimavanserin gets CDSCO Panel nod

This recommendation came after the firm presented a proposal for protocol amendment of the existing protocol no. ICR/21/012 version no. 2.0 dated 27.12.2021 before the committee.

Earlier, the Medical Dialogues Team had reported that, last year in January, drug major Sun Pharma had got approval from the Subject Expert Committee (SEC) functional under the Central Drug Standard Control Organization (CDSCO) to conduct a phase III clinical trial of the new antipsychotic drug Pimavanserin, indicated for the treatment of hallucinations and delusions caused by Parkinson's disease.

Pimavanserin is an atypical antipsychotic used in the treatment of hallucinations and psychosis in patients with Parkinson's disease.

The mechanism by which pimavanserin treats hallucinations and delusions associated with Parkinson's disease psychosis is not fully established. However, it is possible that pimavanserin acts via inverse agonist and antagonist activity at serotonin 5-HT2A receptors with limited effects on serotonin 5-HT2C receptors.

Pimavanserin is an inverse agonist and antagonist of serotonin 5-HT2A receptors with high binding affinity, demonstrating low binding affinity to serotonin 5-HT2C receptors. In addition, this drug exhibits low affinity binding to sigma 1 receptors. Pimavanserin lacks activity at muscarinic, dopaminergic, adrenergic, and histaminergic receptors, preventing various undesirable effects typically associated with antipsychotics.

At the recent SEC meeting for Neurology and Psychiatry on December 16, 2022, the expert panel reviewed the proposal for protocol amendment of the existing protocol no. ICR/21/012 version no. 2.0 dated 27.12.2021, presented by Sun Pharma.

After detailed deliberation, the committee agreed for amendments in existing protocol proposed by the firm subject to the condition that the firm should keep point no. 1 of inclusion criteria, of previously approved protocol as it is i.e.patients of either gender, aged ≥ 40 years, with a documented clinical diagnosis of idiopathic Parkinson's Disease (PD) (as per UK PD Society Brain Bank Clinical Diagnostic Criteria) of duration ≥5.5 years, and Hoehn & Yahr stage ≤3 of previously approved protocol.

Accordingly, the expert panel directed that the firm submit the correct version of protocol no. ICR/21/012 version no. 3.0 dated 25.11.2022 to CDSCO.