Moleculin Biotech, Inc., (NASDAQ:MBRX) ("Moleculin" or the "Company"), a clinical stage pharmaceutical company with a broad portfolio of drug candidates targeting highly resistant tumors and viruses, today announced a presentation at the American Association of Cancer Research (AACR) Annual Meeting held from June 22nd-24th, 2020, illustrating a unique approach to creating drugs capable of reaching tumors hiding in organs where existing anticancer drugs cannot accumulate in therapeutic concentrations. A poster presentation entitled, "Targeting Cancer Sanctuary Sites: A Novel Approach to the Treatment of Lung Localized Tumors," provided an overview of data demonstrating that uniquely high uptake and retention of Annamycin in the lungs results in consistently high in vivo activity against wide range of lung-localized tumors in mice.
"We are very encouraged by this data, as we believe it further demonstrates Annamycin's anti-cancer activity against tumors that evade therapies that may be initially effective in their primary location of origin, but are protected by metastasis to sanctuary organs. In the case of sarcomas treated with the current standard of care, doxorubicin, tumors may be initially responsive in their primary location, but become unresponsive after metastasis to the lungs, which eventually becomes the most likely cause of patients' death," commented Walter Klemp, Chairman and CEO of Moleculin. "This research also sheds light on why doxorubicin, the current standard of care for many types of cancer, is not effective against lung-localized cancer. Subsequently, we believe that Annamycin's ability in animal models to effectively accumulate in the lungs without noticeable side effects offers unique therapeutic opportunities that should be explored for the benefit of cancer patients with lung-localized tumors."
Mr. Klemp concluded: "One of the reasons we are so excited about Annamycin's potential to treat lung-localized tumors is its ability in animal models to accumulate in the lungs and lack of toxic side effects related to the high lung accumulation. This was once again confirmed by the data, as Annamycin accumulated in the lungs at nearly 6 times the level of doxorubicin. Importantly, Annamycin's ability to accumulate in the lungs also led to high anti-tumor activity, which ranged from the inhibition of tumor progression to complete tumor eradication, resulting in significant improvement of survival in all the models tested. We look forward to exploring Annamycin's clinical potential to target tumors localized in the lungs, one of the most common sites of cancer metastasis."
The accepted abstract stated, "The high cytotoxic potency of Annamycin against MDR cancer cells is related, in part, to its ability to overcome ABC transporter-mediated efflux and, in contrast to doxorubicin, achieve high intracellular uptake. A greatly increased concentration of Annamycin in the lung, as compared to doxorubicin, leads to high drug efficacy in vivo in lung-localized tumor models. In summary, our studies (1) support the hypothesis of lungs being a sanctuary site for cancer cells and (2) demonstrate that effective targeting of cancers metastatic to the lung is possible by chemical modification of clinically used but currently ineffective drugs, especially in combination with appropriate drug delivery. In more general terms, these studies indicate that the proposed approach can also lead to the identification and elimination of cancer sanctuary sites other than the lungs and creation of more effective anticancer therapies."