1 February 2019 - - US-based biopharmaceutical company Alexion Pharmaceuticals, Inc. (NASDAQ: ALXN) and US-based biotechnology company Caelum Biosciences have forged a collaboration to develop CAEL-101 for light chain amyloidosis, the companies said.

CAEL-101 is a first-in-class amyloid fibril targeted therapy designed to improve organ function by reducing or eliminating amyloid deposits in patients with AL amyloidosis.

AL amyloidosis is a rare systemic disorder that causes misfolded immunoglobulin light chain protein to build up in and around tissues, resulting in progressive and widespread organ damage, most commonly to the heart and kidneys.

Under the terms of the agreement, Alexion will acquire a minority equity interest in Caelum and an exclusive option to acquire the remaining equity in the company based on Phase 2 data for pre-negotiated economics.

Alexion will make payments to Caelum totaling up to USD 60m, including the purchase price for the equity and milestone-dependent development funding payments.

The collaboration also provides for potential additional payments of up to USD 500m, including the upfront and regulatory and commercial milestone payments, in the event Alexion exercises the acquisition option.

The collaboration will leverage Alexion's expertise in rare disease antibody development and commercial franchise in hematology.

Alexion and Caelum will collaborate on the design of the ongoing development program for CAEL-101. Caelum will be responsible for conducting the development program through the end of Phase 2 and for manufacturing CAEL-101.

CAEL-101 is a first-in-class monoclonal antibody designed to improve organ function by reducing or eliminating amyloid deposits in the tissues and organs of patients with AL amyloidosis.

The antibody is designed to bind to insoluble light chain amyloid protein, including both kappa and lambda subtypes.

In a Phase 1a/1b study, CAEL-101 demonstrated improved organ function, including cardiac and renal function, in 27 patients with relapsed and refractory AL amyloidosis who had previously not had an organ response to standard of care therapy.

CAEL-101 has received Orphan Drug Designation from the US Food and Drug Administration as a therapy for patients with AL amyloidosis and as a radio-imaging agent in AL amyloidosis.

AL amyloidosis is a rare systemic disorder caused by an abnormality of plasma cells in the bone marrow. Misfolded immunoglobulin light chains produced by plasma cells aggregate and form fibrils that deposit in tissues and organs, gradually affecting their function.

This can cause progressive and widespread organ damage and high mortality rates, with death most frequently occurring as a result of cardiac failure.

Current standard of care includes plasma cell directed chemotherapy and autologous stem cell transplant, but these therapies do not address the organ dysfunction caused by amyloid deposition, and up to 80% of patients are ineligible for transplant.

AL amyloidosis is a rare disease but is the most common form of amyloidosis.

There are approximately 22,000 patients across the United States, France, Germany, Italy, Spain and the United Kingdom. AL amyloidosis has a one-year mortality rate of 47%, 76% of which is caused by cardiac amyloidosis.

Alexion is a global biopharmaceutical company focused on serving patients and families affected by rare diseases through the discovery, development and commercialisation of life-changing therapies.

As a specialist in complement biology and inhibition for more than 20 years, Alexion has developed and commercialises two approved complement inhibitors to treat patients with paroxysmal nocturnal hemoglobinuria, as well as the first and only approved complement inhibitor to treat atypical hemolytic uremic syndrome and anti-acetylcholine receptor antibody-positive generalised myasthenia gravis, and is also developing it for patients with neuromyelitis optica spectrum disorder (NMOSD).

Alexion also has two innovative enzyme replacement therapies for patients with life-threatening and ultra-rare metabolic disorders, hypophosphatasia and lysosomal acid lipase deficiency (LAL-D).

In addition, the company is developing several mid-to-late-stage therapies, including a second complement inhibitor, a copper-binding agent for Wilson disease and an anti-neonatal Fc receptor antibody for rare Immunoglobulin G -mediated diseases.

Alexion focuses its research efforts on novel molecules and targets in the complement cascade and its development efforts on the core therapeutic areas of hematology, nephrology, neurology and metabolic disorders.

Caelum Biosciences, founded by Fortress Biotech, Inc. (NASDAQ: FBIO) is a clinical-stage biotechnology company developing treatments for rare and life-threatening diseases.

Caelum's lead asset, CAEL-101, is a novel antibody for the treatment of patients with amyloid light chain amyloidosis.

Phase 1a/1b data support CAEL-101's potential to be a well-tolerated therapy that promotes amyloid resolution.