RedHill Biopharma Ltd., an Israeli biopharmaceutical company focused on late clinical-stage drugs for inflammatory and gastrointestinal diseases, including gastrointestinal cancers, and RESprotect GmbH (RESprotect), a privately-held biotech company located in Dresden, Germany, have entered into a binding exclusive option agreement for the acquisition of the oncology drug candidate RP101 and next generation compounds. RP101 is a proprietary, first-in-class, heat shock protein 27 (Hsp27) inhibitor, administered orally, which may prevent the induction of resistance to chemotherapy (chemoresistance), thus maintaining sensitivity of the tumour to chemotherapy and potentially enhancing patient survival.

Under the terms of the agreement, RedHill has the option to acquire the worldwide exclusive rights to RP101 for all indications, other than to the pancreatic cancer indication in South Korea. RedHill has agreed to pay RESprotect for a one year option, which may be extended by RedHill under certain agreed terms. During the option period, RedHill may, at its discretion, conduct development activities with RP101. If RedHill elects to exercise the option, it will acquire the exclusive rights to RP101 for a total payment, for both the option and the acquisition of the rights, of $100,000, as well as potential milestone payments and tiered royalties on net revenues, ranging from single-digit to mid-teens.

RP101 is an orally administered, patent-protected small molecule which binds to Hsp27, a chaperone protein which is found in abnormally high levels in cancer cells, and inhibits its activity. The overexpression of Hsp27, which results in the amplification of a multidrug-resistance (MDR) gene, has been linked to tumor resistance to cytotoxic drugs and the development of metastasis. Chemoresistance limits the effectiveness of chemotherapy and can ultimately lead to treatment failure. By inhibiting Hsp27, RP101 may prevent chemoresistance and enhance the sensitivity of tumors to chemotherapy. RP101 is based on a new mechanism of action of the anti-viral drug brivudine, a nucleoside analogue approved and marketed in several European countries for the treatment of herpes zoster. RP101 has completed several clinical studies, including Phase II studies in pancreatic cancer. RP101 has been granted Orphan Drug designation for the adjunct treatment of pancreatic cancer by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA).  

Dror Ben-Asher, RedHill's CEO, said: "Today’s acquisition of an option for the Hsp27 inhibitor RP101 reflects RedHill’s increasing strategic focus on new, clinical-stage, orally-administered treatments for patients suffering from gastrointestinal and inflammatory diseases, including pancreatic cancer and other gastrointestinal cancers, where there is a particularly strong need for better therapeutic options. Across several clinical studies, pancreatic cancer patients co-treated with RP101 and one or more chemotherapy agents were found to have longer overall survival than historical control pancreatic cancer patients treated with chemotherapy alone. In a randomized, placebo-controlled Phase II pancreatic cancer study, median overall survival was longer in patients receiving chemotherapy plus RP101 than in those receiving chemotherapy plus placebo in a subset of patients with high body surface area in the US. A scientific advice meeting with Germany’s BfArM provided a possible pathway forward for the development of RP101." Ben-Asher added: "there are many government and other research and development grants available for gastrointestinal cancers and specifically for pancreatic cancer which we could potentially pursue, and there is also potential for regulatory designation of RP101 as an expedited program for a serious condition and unmet medical need. We are looking forward to exploring further development of RP101 with our new partners at RESprotect.”

Prof. Rudolf Fahrig, RESprotect’s CEO said: "We are delighted to sign this option agreement with RedHill Biopharma and look forward to work with our new partners at RedHill on the development of RP101.”

RP101, invented by Prof. Rudolf Fahrig at the Fraunhofer Institute for Toxicology and Experimental Medicine (ITEM) in Hannover, Germany, is an orally administered, patent-protected small molecule which binds to heat shock protein 27 (Hsp27) and inhibits its multidrug-resistance gene amplification activity. Hsp27 is a chaperone protein which is found in abnormally high levels in cancer cells and plays a key role in the development of therapy resistance and metastases. By inhibiting Hsp27, RP101 may prevent the induction of resistance to chemotherapy (chemoresistance) and maintain sensitivity of tumors to chemotherapy, thus potentially enhancing patient survival. RP101 has completed several phase I and Phase II clinical studies with a total of 249 subjects treated, including phase II studies in pancreatic cancer. RP101 has been granted Orphan Drug designation for the adjunct treatment of pancreatic cancer by the US Food and Drug Administration (FDA) and the European Medicines Agency (EMA).  

RESprotect GmbH is a Dresden-based, privately-held biotech company specializing in the development of drugs for the prevention and treatment of chemotherapeutic drug resistance and radiation therapy resistance.