Exhibit 99.1

JOINT FILING AGREEMENT

In accordance with Rule 13d-1(k) of the Securities Exchange Act of 1934, as amended, the undersigned agree to the joint filing on behalf of each of them of a Statement on Schedule 13G (including any and all amendments thereto) with respect to the common stock of Adverum Biotechnologies, Inc. and further agree that this Joint Filing Agreement shall be included as an Exhibit to such joint filing. In evidence thereof, the undersigned, being duly authorized, hereby execute this Joint Filing Agreement as of February 12, 2018.

Dated: February 12, 2018	Bpifrance Participations S.A.
	By:	/s/ Sophie Paquin
	Name:	Sophie Paquin
	Title:	Director of Legal Affairs
Dated: February 12, 2018	Fonds Biotechnologies Innovantes et Maladies Rares
	By:	/s/ Sophie Paquin
	Name:	Sophie Paquin
	Title:	Director of Legal Affairs (Bpifrance Investissement S.A.S.)
Dated: February 12, 2018	Bpifrance Investissement S.A.S.
	By:	/s/ Sophie Paquin
	Name:	Sophie Paquin
	Title:	Director of Legal Affairs
Dated: February 12, 2018	Caisse des Dépôts
	By:	/s/ Joel Prohin
	Name:	Joel Prohin
	Title:	Head of Portfolio Management

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Dated: February 12, 2018	Epic Bpifrance
	By:	/s/ Sophie Paquin
	Name:	Sophie Paquin
	Title:	Director of Legal Affairs
Dated: February 12, 2018	Bpifrance S.A.
	By:	/s/ Boubakar Dione
	Name:	Boubakar Dione
	Title:	Group Director of Legal Affairs

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