Lurbinectedin, a drug used in the treatment of certain types of cancer, should not be stored in a freezer. The physicochemical stability of lurbinectedin has been studied, and it is recommended to store the drug at controlled room temperature between 20°C to 25°C (68°F to 77°F) [2]. Freezing temperatures can potentially compromise the stability and effectiveness of the medication. Therefore, it is advisable to adhere to the storage instructions provided by the manufacturer and healthcare provider to ensure the drug's potency and safety.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LURBINECTEDIN
[2] https://journals.lww.com/ejop/fulltext/2021/09000/physicochemical_stability_of_lurbinectedin.1.aspx
[3] https://www.accessdata.fda.gov/drugsatfda_docs/label/2020/213702s000lbl.pdf