Medical Information

The therapeutic effect of Pimitesib needs to be evaluated based on individual conditions, and discontinuation should strictly follow medical guidance to avoid adverse reactions. The following will explain from two aspects: efficacy evaluation and precautions for discontinuation of medication.

1. Evaluation of treatment efficacy

(1) Clinical response indicators

The efficacy needs to be evaluated through regular imaging examinations and tumor marker detection, with complete remission rate and partial remission rate as the core evaluation indicators. During the treatment period, efficacy confirmation is required every 8-12 weeks.

(2) Progression free survival period

Median progression free survival (mPFS) is an important efficacy parameter, and clinical studies have shown differences among different tumor types. The actual therapeutic effect may be affected by the genetic mutation status.

(3) Disease control rate

The proportion of cases that include complete remission, partial remission, and disease stability reflects the comprehensive control ability of drugs on tumor growth. It is necessary to make a comprehensive judgment based on the quality of life score.

2 Precautions for discontinuation of medication

(1) Planned discontinuation of medication

If complete remission is achieved and maintained for more than 6 months, discontinuation of medication may be considered, but gradual reduction is required. The reduction plan should refer to the stepwise reduction pattern of bimetinib.

(2) Adverse reactions: discontinuation of medication

If there is a level 4 toxicity or a level 3 irreversible toxicity, the medication needs to be permanently discontinued. Hepatotoxicity needs to be evaluated for restarting treatment after ALT/AST levels have been restored to ≤ 1.

(3) Disease progression and discontinuation of medication

After confirming the progress of imaging, the medication should be discontinued and the conversion plan should be changed. But when isolated lesions progress, local treatment combined with the original plan can be considered to continue medication.

(4) Monitoring after discontinuation of medication

After discontinuing the medication, continuous monitoring is still required for 3 months, with a focus on the organ function of the original adverse reactions. Patients with cardiac toxicity need to undergo quarterly follow-up echocardiography.

(5) Discontinue medication for special populations

The adverse reactions of elderly patients disappear slowly after discontinuation of medication, and the monitoring period needs to be extended. Patients with liver dysfunction should strengthen bilirubin testing after discontinuing medication.