Editas Medicine will combine its gene-editing technologies with Adverum Biotechnologies’ next-generation adeno-associated viral (AAV) vectors in a collaboration to develop new therapies for up to five eye diseases, the companies said today.

Through the genome-editing medicine collaboration, Adverum could generate at least $1 million upfront, plus millions more in potential option fees, milestone payments, and royalties.

The companies did not detail which eye diseases they were targeting with new treatments, except to say they were “inherited retinal diseases.” In an investor presentation last month, Editas disclosed two eye disorders—Leber congenital amaurosis 10 and ocular herpes simplex virus (HSV)—within its range of disease applications for CRISPR-based medicines.

Under the companies’ Collaboration, Option, and License Agreement, Editas agreed to pay Adverum a $1 million upfront “fee” to evaluate Adverum vectors for use in clinical development, plus an additional option exercise fee of $1 million for an exclusive license to Adverum’s next-generation AAV vectors for use in each indication chosen as part of the collaboration.

The companies said they plan to conduct research focused on the testing and optimizing Adverum’s AAV vectors for potential Editas genome-editing products for the indications. Editas agreed to fund all preclinical activities related to the collaboration, with an unspecified part of the upfront fee to be credited against that funding.

Editas may exercise its option to develop a first indication until the first anniversary of the collaboration. Editas has until the third anniversary to exercise options for the four other Indications—but the latter option would expire by the end of the second anniversary if Editas hasn’t pursued an initial indication by then, Adverum stated in a regulatory filing.

For each option Editas exercises, Adverum will be eligible to receive up to a “mid-teen million” dollar amount in development and commercialization milestone payments for the product, plus tiered royalties between the mid-single digits and low teens on net sales, subject to adjustments, Adverum’s filing added.

If Editas opts to develop a therapy by using a designated alternative vector, Adverum would receive smaller development milestone payments and tiered royalties for the product.

Editas’ latest collaboration is its third in as many weeks. On August 3, the company said it will license from Massachusetts General Hospital (MGH) intellectual property and technology related to high-fidelity Cas9 nucleases and Cas9 protospacer adjacent motif (PAM) variants, in a deal of undisclosed value.

And on July 28, Editas partnered with the San Raffaele Telethon Institute for Gene Therapy (SR-TIGET) to research and develop genome-edited hematopoietic stem cell (HSC) and T-cell therapies, in another partnership of undisclosed value.

Adverum changed its name in May from Avalanche Biotechnologies following the completion of its acquisition of Annapurna Therapeutics.