Merck & Co. is giving back rights to anti-ADDL antibody therapeutics and diagnostics for Alzheimer disease to Acumen Pharmaceuticals and separately buying the exclusive, worldwide license to Exelixis’ PI3K-delta R&D program for $12 million.
Exelixis could receive development and regulatory milestones in multiple indications of up to $239 million plus sales performance milestones and royalties. The firm will be eligible for milestones and royalties relating to the development of products emerging from both its own PI3K-delta program and from certain compounds arising from Merck’s internal PI3K-delta program during a certain period.
The most advanced candidate in Exelixis' PI3K-delta program is in preclinical testing. Under terms of the deal Merck takes over all research, development, and commercialization activities for compounds originating from the program.
Exelixis has already licensed out pan-PI3K inhibitors that are in clinical development against cancer. It says licensing out the specific PI3K-delta program will provide it with the resources needed to continue development and commercialization of lead compound cabozantinib (XL184), a dual MET and VEGF pathway inhibitor in late-stage development for medullary thyroid and prostate cancers.
The firm’s clinical-stage PI3K candidates, XL147 and XL765, are in Phase II and Phase I/II, respectively, in partnership with Sanofi. The two firms are also collaborating on continued development of isoform selective PI3Kalpha and PI3Kbeta-targeting candidates.
With regard to Merck’s arrangement with Acumen, all rights licensed to Merck will be returned. Acumen will also receive certain rights to patent applications and know how generated during the term of the agreement. The deal was originally inked in 2003 and amended in 2006.
Anti-ADDL antibodies have high selectivity for soluble amyloid beta oligomers versus monomeric amyloid beta peptides or insoluble amyloid beta aggregates, according to Acumen. The company believes this selectivity will favorably differentiate Acumen anti-ADDL immunotherapies compared to amyloid beta immunotherapies.
"The recent failures of a gamma secretase inhibitor and the limited efficacy observed so far with nonselective amyloid beta immunotherapies indicates that industry may have been focused on suboptimal targets within the amyloid beta pathways," states Franz Hefti, Ph.D., newly appointed president and CEO of Acumen.
"Our Merck colleagues successfully advanced anti-ADDL antibody therapeutics to a late preclinical development stage based on antibodies that we believe will allow Acumen to develop a best-in-class, disease-modifying therapy for Alzheimer disease."