Checkmate Pharmaceuticals (Checkmate), a clinical-stage biopharmaceutical company focused on developing novel approaches for cancer immunotherapy, announced that it has completed a $27 million Series B preferred financing led by new investor F-Prime Capital Partners. The round also includes existing investors, Sofinnova and venBio Partners.

Proceeds from the financing will be used to further advance clinical development of CMP-001, a first-in-class CpG-A oligonucleotide that activates the innate immune system via Toll-like receptor 9 (TLR9), and which is currently being studied in a Phase 1b trial in combination with pembrolizumab in primary refractory melanoma patients who have either progressed on or failed to respond to anti-PD-1 therapy. Specifically, the additional funding will enable Checkmate to conduct advanced studies in melanoma as well as pursue studies in additional indications in which the combination approach may prove to be of clinical benefit. The combination therapy of CMP-001 and pembrolizumab has the potential to increase the proportion of cancer patients who respond to checkpoint inhibitor therapies and to increase the magnitude and duration of the anti-tumor responses, providing added clinical benefit.

The company also announced today the appointment of Karen Brennan as Chief Operating Officer. Ms. Brennan brings more than 30 years of experience in building and leading early and late stage clinical and development operations teams to her role at Checkmate. She recently held the position of Vice President of Clinical and Development Operations at Forum Pharmaceuticals, and prior to that held similar positions of progressively increasing responsibility at Millennium/Takeda and other companies.

"We are grateful for the continued strong support from our existing investors as we welcome the new support from F-Prime," said Art Krieg, CEO of Checkmate. "In addition, we are delighted to benefit from Karen's expertise and experience as we continue clinical development of CMP-001 in melanoma and expand into other indications."

"Checkmate is making excellent progress in demonstrating that CMP-001 in combination with pembrolizumab is providing clinical benefit to PD-1-refractory patients with advanced melanoma," said Ben Auspitz, Partner at F-Prime Capital Partners. "We are pleased to be joining the Series A investors in supporting this innovative work to convert cold tumors to hot, advancing the development of combination therapies in oncology."

About CMP-001

CMP-001 comprises a CpG-A oligonucleotide packaged within a virus-like particle. It is designed to activate the innate immune system via Toll-like receptor 9 (TLR9) and mediate tumor control by the subsequent induction of both innate and adaptive anti-tumor immune responses. CMP-001 is the only CpG-A oligonucleotide in clinical development.

About Checkmate

Checkmate Pharmaceuticals is a clinical stage company pursuing a novel approach to specifically activating the innate arm of the immune system to recognize and ultimately destroy tumor cells. The company is leveraging its expertise and the vast body of knowledge in the field of CpG oligonucleotides and is validating an approach that will combine the ability of CpG DNA to activate an anti-tumor T cell response with checkpoint inhibition to overcome a tumor's ability to mute the immune response. Checkmate is a privately held company headquartered in Cambridge, MA. Information regarding Checkmate is available at www.checkmatepharma.com.

About F-Prime Capital Partners

F-Prime Capital is a global venture capital firm investing in life sciences, healthcare and technology. Since 1969, F-Prime has worked closely with entrepreneurs and academics to create innovative solutions to some of the world's most significant challenges in healthcare and technology. For more information, please visit www.fprimecapital.com.