Setting the Stage for Multipurpose Drugs

Existing drugs can be repurposed for other conditions – but new drugs can also be developed with multipurpose roles in mind.

GLP-1 agonists, for example, have seen huge surges in demand for their successes in treating type 2 diabetes and for weight loss. But could the promise of multipurpose drugs extend to other key therapeutic areas?

We spoke with Dr. Bryan Oronsky, chief development officer at EpicentRx, to discover more about the promise of multipurpose drugs and the potential of EpicentRx’s nibrozetone (RRx-001) for several conditions, including complications of chemo- and radiotherapy.

Sarah Whelan (SW): Can you explain what multipurpose drugs are and their potential benefits? 

Bryan Oronsky (BO): A multipurpose drug is one that, by design, treats multiple conditions or indications. Nibrozetone was specifically engineered to:

• Fragment and release the free radical nitric oxide under conditions of low oxygen or hypoxia, which applies to several disease states.
• Reduce inflammation and free radical stress in well-oxygenated, normal tissues.
• Penetrate across the normally impermeable blood–brain barrier.
• Cause minimal side effects.

The benefits of such a multipurpose strategy are that nibrozetone has already been used extensively and safely in humans and evaluated in various stages of the drug development pipeline. Therefore, its safety, pharmacology, toxicology, manufacturing and formulation are well-characterized and well-established, which means it is not necessary to reinvent the wheel for each indication.  

SW: How does nibrozetone work, and how does it fit into this multipurpose category? 

BO: Nibrozetone is a bispecific molecule, meaning that it combines at least two main mechanisms of action in one. The first mechanism is direct and potent inhibition of the NLRP3 inflammasome – this is an ensemble of proteins whose activation is responsible for the initiation and perpetuation of inflammation – which makes nibrozetone an anti-inflammatory. Inflammation and especially chronic or persistent inflammation from activation of the immune system is at the root of many, if not all diseases, which makes nibrozetone broadly applicable and broadly active.

The second mechanism is the release of the vasodilator, nitric oxide (NO), only under poorly oxygenated conditions. The on-demand release of NO increases blood flow and oxygen delivery to poorly perfused tissues in diseases like cancer, myocardial infarction (MI, or heart attack), heart failure, stroke, high blood pressure (hypertension), pulmonary hypertension and neurodegenerative diseases – among others – which is very beneficial. Also, I mention that in 400 or so patients, no so-called dose-limiting toxicities have been observed.

SW: You mention that nibrozetone has shown potential in several different diseases, including neurodegenerative diseases. Could you elaborate on this? 

BO: As discussed above, nibrozetone is a broadly active drug in several disease states including neurodegeneration. In neurodegeneration, not only do brain cells (neurons) decay, but also certain regions of the brain are subject to damage from neuroinflammation, low blood flow and hypoxia. Nibrozetone crosses the blood–brain barrier, the otherwise impermeable membrane between the blood and the brain, where it counteracts these damaging hypoxic and/or inflammatory conditions. Experimental data indicates that nibrozetone rescues and/or prevents further injury to areas of the brain in Parkinson’s disease, Alzheimer’s disease and amyotrophic lateral sclerosis/motor neuron disease.

SW: Nibrozetone has been granted Fast Track designation by the US Food and Drug Administration (FDA) for severe oral mucositis in head and neck cancer. Can you explain what this means, and its potential for these cancers? 

BO: FDA Fast Track designation speeds up the drug approval process for therapies like nibrozetone that treat serious conditions and fill an unmet medical need, which makes Fast Track highly coveted. The unmet need in this case is severe oral mucositis. This is a common, severely debilitating and often life-threatening condition that produces excruciatingly painful oral ulcers resulting from treatment with chemotherapy and radiation for head and neck cancer. It can make swallowing, eating and drinking difficult to impossible. Severe weight loss, malnutrition, dehydration and local infection usually follow, requiring hospitalization, treatment with narcotics, the introduction of a feeding tube and the withdrawal of treatment, which predisposes to cancer recurrence and decreased survival.

SW: What further studies do you have planned? For example, clinical trials? 

BO: Nibrozetone is currently in a Phase 3 trial – the last trial prior to approval – for the treatment of platinum-resistant small cell lung cancer (SCLC), which accounts for about two-thirds of SCLC patients and for whom most therapies are ineffective.

We also have another lead therapy called AdAPT-001, an oncolytic adenovirus, that has demonstrated very promising results from an ongoing Phase 2 clinical trial in a type of soft tissue tumor called sarcoma. An oncolytic adenovirus refers to a common cold virus that is engineered to attack and lyse or eliminate tumors specifically. In addition, this virus expresses a transforming growth factor beta (TGF-β) trap in the course of its infection that neutralizes a protein called TGF-β, which tumors use to suppress and escape from the immune system.

Dr. Bryan Oronsky was speaking to Dr. Sarah Whelan, Science Writer for Technology Networks.

About the interviewee:

Dr. Bryan Oronsky serves as chief development officer at EpicentRx. He combines firsthand clinical experience as a physician with 17 years of pharmaceutical development experience.