Lurbinectedin is a drug that has been recently investigated for its effectiveness against breast cancer. According to Drug Patent Watch [1], Lurbinectedin is a selective inhibitor of RNA polymerase II, which is an enzyme that plays a crucial role in transcription. The drug has been shown to inhibit the growth of cancer cells and induce apoptosis, or programmed cell death, in several types of cancer.

A study published in The Lancet Oncology [2] evaluated the safety and efficacy of lurbinectedin in patients with advanced solid tumors, including breast cancer. The study found that lurbinectedin showed promising activity against breast cancer, with an overall response rate of 25% in patients with advanced breast cancer. The study also reported that the drug was generally well-tolerated, with manageable side effects.

Another study published in the Journal of Clinical Oncology [3] investigated the combination of lurbinectedin with another drug, called pembrolizumab, in patients with metastatic triple-negative breast cancer. The study found that the combination therapy was safe and showed promising activity against the cancer, with an overall response rate of 33%.

In conclusion, based on the available evidence, lurbinectedin appears to be a promising drug for the treatment of breast cancer. The drug has shown activity against the cancer in several studies and has been generally well-tolerated. However, further research is needed to determine the optimal use of lurbinectedin in breast cancer treatment and to evaluate its long-term safety and efficacy.

Sources:
[1] https://www.drugpatentwatch.com/p/tradename/LURBINECTEDIN
[2] https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(18)30737-X/fulltext
[3] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8165873/