Off-label drugs for cancer

Off-label drugs are drugs that are used for a disease or condition other than the one they were originally approved for. For example, Metformin was originally approved to treat 2 diabetes but is also used off-label to treat cancer.

Here are some off-label drugs that have shown efficacy in cancer treatment.

Bisphosphonates (anti-hypercalcemia drugs)

This study involving 18 766 women with early breast cancer, says:
…When the study authors looked at the findings according to the trial participants’ menopausal status, they found that treatment with adjuvant bisphosphonates had no effect on any of the outcomes for premenopausal women. However, among the 11,767 postmenopausal women included in the analysis, the use of bisphosphonates was associated with statistically significant reductions in distant recurrence, in bone recurrence, and in death from breast cancer.

Niclosamide

Niclosamide belongs to the family of medicines called anthelmintics. Anthelmintics are medicines used in the treatment of worm infections.

Study: In conclusion, the present study offered new ideas for the treatment of chemoresistant HER2-positive breast cancer…Niclosamide combined with cisplatin may be considered as a novel treatment therapy for chemoresistant HER2-positive breast cancer.

Niclosamide, has been repurposed for cancer treatment due to its ability to disrupt multiple oncogenic signaling networks, such as Wnt/β-catenin, NF-κB and STAT3, all of which has fundamental roles in the survival, proliferation, and invasiveness and metastasis of tumors. (study)

Therefore, niclosamide holds great potential for the treatment of cancers and our present study provides strong support for its use in the treatment of TNBC. (study).

Mifepristone

This study of 34 ovarian cancer patients treated with Mifepristone says: Nine (26.5%) of these patients had a response to Mifepristone. Three (9%) patients had a complete response, and six (17.5%), a partial response…Laboratory studies show thatMifepristone can target cancer stem cells. Conclusion: Mifepristone has activity against ovarian cancer resistant to cisplatin and paclitaxel. The drug is well tolerated.

Case Report: We show long-term high-quality survivalfollowing single-agent treatment with a progesterone receptor antagonist in two cases of advanced metastatic cancer.

This study says: In summary, we have shown that mifepristone is a potent blocker of ovarian cancer growth in vitro and in vivo. The feasibility of using mifepristone to enhance the efficacy of conventional chemotherapy for ovarian cancer is encouraging and requires further investigation.

Page updated February 2026