Allschwil, Switzerland, October 29, 2020

Polyphor completes recruitment in Phase III trial of balixafortide in metastatic breast cancer

Polyphor AG (SIX: POLN) today announces that it has completed recruitment in its FORTRESS Phase III study of balixafortide in metastatic breast cancer. A total of 411 patients have been recruited, including 323 in the third line cohort and 88 patients in the second line cohort. Although recruitment is closed, Polyphor will allow all patients that have already registered for the study to be enrolled. This may increase the final number of patients enrolled in the study to approximately 430. As previously communicated, data on the key primary endpoint of FORTRESS, progression free survival (PFS) in the overall population, is planned for Q4 2021. An analysis of the objective response rate (ORR) in eligible patients in third and later lines of chemotherapy is planned for Q2 2021.

"We are pleased to have completed recruitment in this important study in a timely manner. Balixafortide is currently the only potent blocker of CXCR4, a key molecule involved in tumor growth and metastasis, in Phase 3 clinical development for a solid tumor and as such, it has significant potential to improve the lives of patients," said Dr. Frank Weber, Chief Medical and Development Officer at Polyphor. "We would like to take this opportunity to thank first and foremost the patients, but also the investigators and the local staff as well as our employees for their active participation in this study. This great effort has enabled us to complete the recruitment as planned, despite the difficulties caused by the current pandemic."

The FORTRESS study (POL6326-009) is an international, multicenter, randomized active-controlled, open-label Phase III trial which investigates the efficacy, safety and tolerability of intravenous balixafortide given with eribulin versus eribulin alone in the treatment of HER2 negative, locally recurrent or metastatic breast cancer.

Subject to the data, Polyphor may submit a filing for accelerated approval in the US based on the analysis of the ORR, confirmed by an independent blinded review, and of the associated durability of response. The full approval would be based on the magnitude of PFS on blinded independent review, supported by an overall survival trend favoring the balixafortide arm and a favorable risk-benefit profile.

For more information about the POL6326-009 clinical trial of balixafortide, please visit www.clinicaltrials.gov (Identifier: NCT03786094)

For further information please contact:

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Bernhard Schmid
LifeSci Advisors
+41 44 447 12 21
bschmid@lifesciadvisors.com

About Polyphor
Polyphor is a research-driven clinical-stage, Swiss biopharmaceutical company committed to discovering and developing best-in-class molecules in oncology and antimicrobial resistance leveraging the company's leading macrocyclic peptide technology platform. Polyphor is advancing balixafortide (POL6326) in a Phase III trial in combination with eribulin in patients with advanced breast cancer and exploring its potential in other cancer indications. In addition, it has discovered and is developing the Outer Membrane Protein Targeting Antibiotics (OMPTA). OMPTA are potentially the first new class of antibiotics in clinical development in the last 50 years against Gram-negative bacteria. The company's lead OMPTA program is an inhaled formulation of murepavadin for the treatment of Pseudomonas aeruginosa infections in patients with cystic fibrosis. Polyphor is based in Allschwil near Basel and is listed on the SIX Swiss Exchange (SIX: POLN). For more information, please visit www.polyphor.com.

Disclaimer
This press release contains forward-looking statements which are based on current assumptions and forecasts of the Polyphor management. Known and unknown risks, uncertainties, and other factors could lead to material differences between the forward-looking statements made here and the actual development, in particular Polyphor's results, financial situation, and performance. Readers are cautioned not to put undue reliance on forward-looking statements, which speak only of the date of this communication. Polyphor disclaims any intention or obligation to update and revise any forward-looking statements, whether as a result of new information, future events or otherwise.