Lurbinectedin is a medication used in the treatment of certain types of cancer. While the provided sources do not explicitly mention the exact timeframe for how quickly lurbinectedin works, they do provide some insights into its efficacy and clinical trials.

Lurbinectedin, marketed under the trade name Zepzelca, is a novel anticancer drug that has shown promise in the treatment of specific types of cancer, including small cell lung cancer (SCLC) and metastatic triple-negative breast cancer (TNBC). It works by targeting and inhibiting the activity of RNA polymerase II, an enzyme involved in the transcription process of DNA to RNA, ultimately leading to cancer cell death [1].

Clinical trials play a crucial role in determining the effectiveness and safety of drugs like lurbinectedin. The National Cancer Institute (NCI) has been conducting clinical trials to evaluate the efficacy of lurbinectedin in various cancer types. These trials provide valuable information on the drug's effectiveness, side effects, and overall response rate [3].

The sources indicate that lurbinectedin has demonstrated promising results in clinical trials for SCLC and TNBC. In a Phase II clinical trial for SCLC, lurbinectedin showed an overall response rate of 35.2%, with a median duration of response of 5.3 months [2]. In another Phase II clinical trial for metastatic TNBC, lurbinectedin demonstrated an overall response rate of 23.1% [2].

While the exact timeframe for how quickly lurbinectedin works is not explicitly mentioned in the provided sources, it is important to note that the response rate and duration of response can vary depending on the individual patient and the specific cancer being treated. It is best to consult with a healthcare professional for more detailed information regarding the specific treatment plan and expected response timeframe.

In conclusion, lurbinectedin is a promising anticancer drug that has shown effectiveness in the treatment of SCLC and TNBC. Clinical trials have demonstrated positive response rates, although the exact timeframe for how quickly lurbinectedin works is not explicitly mentioned in the provided sources. It is important to consult with a healthcare professional for more specific information regarding the treatment timeline and individual response to lurbinectedin.

Sources:
[1] Drug Patent Watch. Lurbinectedin. Retrieved from: https://www.drugpatentwatch.com/p/tradename/LURBINECTEDIN
[2] National Center for Biotechnology Information. Lurbinectedin: A Novel Agent for the Treatment of Small Cell Lung Cancer and Triple-Negative Breast Cancer. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8165873/
[3] National Cancer Institute. Lurbinectedin. Retrieved from: https://www.cancer.gov/research/participate/clinical-trials/intervention/lurbinectedin