-- CBM588 plus nivolumab/ipilimumab improved ORR and PFS compared to nivolumab/ipilimumab alone --

-- First randomized study to prospectively assess a live bacterial product to modulate the GI microbiome in combination with CPIs --

MOUNTAIN VIEW, Calif.--(BUSINESS WIRE)--Osel Inc., a company developing live biotherapeutic products (LBPs) for diseases linked to the disruption of the human microbiome, announced today that City of Hope, a world-renowned independent cancer and diabetes research and treatment center, presented data from a Phase 1b trial showing that an LBP, CBM588 (Clostridium butyricum MIYAIRI 588^� strain), plus nivolumab/ipilimumab improved overall response rate (ORR) and progression-free survival (PFS) compared to nivolumab/ipilimumab alone in patients with metastatic renal cell carcinoma (RCC).

Osel licensed the rights for the pharmaceutical use of CBM588 in the United States, Canada and Europe from Miyarisan Pharmaceutical Co., Ltd., and has a clinical trial agreement for the CBM588 study with City of Hope.

The data were presented at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting by City of Hope�s Luis Meza, a postdoctoral fellow, and Sumanta K. Pal, M.D., clinical professor, Department of Medical Oncology & Therapeutics Research. The presentation titled First results of a randomized phase IB study comparing nivolumab/ipilimumab with or without CBM588 in patients with metastatic renal cell carcinoma (Abstract #4513) is part of the session titled Genitourinary Cancer � Kidney and Bladder.

�We are very pleased with results generated from this clinical study,� said Thomas Parks, Ph.D., Head of Development at Osel. �There is considerable interest in microbiome modulation to enhance immune checkpoint inhibitor efficacy that is more consistent and scalable than fecal transplants. These data are an encouraging indicator of potential patient benefit in an initial indication of metastatic RCC.�

CBM588 is a spore forming anaerobe that produces short chain fatty acids, mainly butyric acid, which is a well-known energy source of intestinal epithelium. The bacterial strain exerts several beneficial effects through multiple modes of action, including inhibition of pathogenic microorganisms, immunomodulatory activities and restorative effects on intestinal dysbiosis.

�Adjunctive treatment with CBM588 is associated with improvements in response rate and PFS in patients treated in combination with standard of care versus standard of care alone � there is also a compelling trend favoring overall survival early on,� Pal said. �These results warrant further investigation in a larger multi-center trial.�

CBM588 is manufactured and marketed in Japan by Miyarisan Pharmaceutical as a prescription product known as Clostridium butyricum MIYAIRI 588^� strain for the treatment of gastrointestinal (GI) indications. It has an excellent safety profile in all age groups and immunocompromised patients, as confirmed by post-marketing surveillance.

�Microbiome analysis showed a statistically significant increase in Bifidobacteria in CBM588 treated clinical responders compared to CBM588 treated non-clinical responders or standard of care patients,� said Motomichi Takahashi, Ph.D., Executive Senior Director, Miyarisan Pharmaceutical. �These preliminary data support the GI microbiome being successfully modulated as a mechanism of clinical efficacy.�

About Osel Inc.

Osel Inc., a privately held biopharmaceutical company based in Mountain View, California, is focused on the development and commercialization of a portfolio of LBPs to prevent or treat medical conditions resulting from disruption of the human microbiome (dysbiosis). The company is a pioneer in the field of LBPs and is actively pursuing multiple indications in cancer and women�s health.

About Miyarisan

Miyarisan Pharmaceutical Co., Ltd., is a live biotherapeutic pharmaceutical company based in Tokyo, Japan. The company was founded in 1947 and its main portfolio, Clostridium butyricum MIYAIRI 588^� strain (CBM588), is the most prescribed pharmaceutical product containing live microorganisms in Japan and other Asian countries.

Contacts

Osel:

Chris Lieu

Bioscribe, Inc.

Tel: (310) 528-7486

Email: [email protected]