Class Notes (836,321)
Canada (509,732)
Chemistry (644)
CHEM564 (32)
Lecture 19

CHEM564 Lecture 19: analysis of Romiplostim

2 Pages
Unlock Document

Christopher Cairo

Romiplostim (AMG 531, Nplate) In the past, although scientists knew that there was a TPO shortfall in ITP patients, they could not find any drugs to 1 replace the shortfall or stimulate platelet production. Most treatments suppress the antiplatelet antibodies production or regulate platelet consumption to hinder excessive platelet destruction. However, Romiplostim helps ITP patients need less immunosuppressive therapy and it is a good alternative for other therapies such as Immunosuppressive therapy (corticosteroids, rituximab, vinca alkaloids, azathioprine, cyclosporine A, cyclophosphamide, mycophenolate mofetil), Intravenous immunoglobulin (Fc receptor blockade), and Surgical therapy (splenectomy). Although Corticosteroid is the first choice of ITP treatment, it has intolerable side effects because immune tolerance disposes patients to infection (e.g. Cushing’s syndrome, high blood pressure, glaucoma, stimulation of osteoporosis, and death). For acute bleeding, anti-D antibodies and platelet transfusions are necessary treatment. Although splenectomy is an effective treatment for who are incompatible to other methods, 1 physicians try to postpone this surgery because of its inherent risks in the procedure. Pharmacodynamic/pharmacokinetic results has proved that although this dug is active in some animals such as dogs, mice, rabbits, rats, and monkeys, nonhuman primates (NHP) show less responses compared to humans. According to the NHP data, 10 g/kg dose was a no-effect dose. Surprisingly, in phase 1, when the first volunteer received this dose, his platelet counts raised sixfold above baseline. Results of this trial reveal the relationship between dose and response. Dose of 1 and 3µg/kg can double the platelet counts in healthy humans. The evidence of Romiplostim’s effect on platelet response takes 3-5 days and peak counts will be observed 12–16 days after 1,3 starting the treatment. During a double-blind, phase 1 and 2, with a single dose of 0.3, 1, or 2 µg/kg, although Romiplostim indicated headache and feeling hot in most of healthy volunteer, it increased platelet counts more than 150% of baseline in most of them. Romiplostim can displace TPO from TPO receptor to induce platelet production. Culture of TPO and Romiplostim with murine marrow cells indicated Romiplostim is a competitive ligand for TPO receptor and it never impair the ability of TPO. 4,5Determination of Romiplostim platelet clearance in the optimal dose was complicate. Researchers still try to know if pharmacodynamics response to Romiplostim is the combination of both Romiplostim and endogenous TPO and whether TPO can affect Romiplostim clearance or conversely. 3 In a long-term weekly subcutaneously treatment, the pharmacokinetic data indicate that the serum concentrations of Romiplostim
More Less

Related notes for CHEM564

Log In


Join OneClass

Access over 10 million pages of study
documents for 1.3 million courses.

Sign up

Join to view


By registering, I agree to the Terms and Privacy Policies
Already have an account?
Just a few more details

So we can recommend you notes for your school.

Reset Password

Please enter below the email address you registered with and we will send you a link to reset your password.

Add your courses

Get notes from the top students in your class.