Arena Pharmaceuticals is ponying up $60 million upfront and investing $10 million in Aristea Therapeutics to collaborate on the latter’s inflammatory disease program and snag the option to acquire its partner. Arena also chipped into Aristea’s $63 million series B round, led by Fidelity Management & Research Company.
Aristea, an AstraZeneca spinout, is developing the drug, RIST4721, for palmoplantar pustulosis (PPP), a rare, inflammatory disorder that causes blisterlike sores to form on the palms of the hands and soles of the feet.
There are no treatments specifically for PPP, but patients may use topical steroids, moisturizers or ultraviolet light therapy to ease symptoms. Aristea’s drug is designed to tackle PPP at the source by dialing down CXCR2, a receptor that plays a role in recruiting neutrophils, or white blood cells, to areas of inflammation.
“We like RIST4721’s CXCR2-targeted mechanism of action, and we see high unmet need in the rare PPP market,” wrote RBC Capital Markets analyst Kennen McKay in a note to clients Tuesday evening.
“We like the deal noting potential for rapid proof of principal/concept for RIST4721 in this rare disease with very high unmet need,” MacKay added. “Furthermore we note the deal structure incentivizes both Aristea & ARNA toward development of the asset.”
Aristea plans to start a phase 2b study of RIST4721 later this year and plans to develop the drug for two more inflammatory conditions: familial Mediterranean fever and Behcet’s disease, the company said in a statement about its financing. Arena will have the option to acquire Aristea once the phase 2b PPP study has wrapped.
During that option period, the duo may also explore the development of RIST4721 for other neutrophil-mediated diseases, such as hidradenitis suppurativa, a skin condition that leads small, painful lumps to form under the skin, and inflammatory bowel disease, according to a statement.
While it works on RIST4721 with Arena, Aristea will use its series B proceeds to add more programs to its preclinical and preclinical pipeline, Aristea CEO James Mackay, Ph.D. said in a statement.
“The collaboration and option agreement with Aristea provides Arena with an opportunity to bolster our early- to mid-stage immunology pipeline in two of our core therapeutic areas, dermatology and gastroenterology,” said Arena CEO Amit Munshi in the statement.
Arena has several programs in phase 2 and phase 3, including etrasimod, in development for ulcerative colitis, Crohn’s disease, eosinophilic esophagitis, atopic dermatitis and alopecia areata. It’s also developing ralinepag for pulmonary arterial hypertension, olorinab for pain linked to irritable bowel syndrome and temanogrel for coronary microvascular obstruction.