FDA Grants Fast Tracks SQZ-PBMC-HPV for HPV16+ Advanced/Metastatic Solid Tumors

The FDA has granted fast track designation to SQZ-PBMC-HPV for the treatment of patients with HPV16-positive advanced or metastatic solids tumors, according to an announcement by SQZ Biotechnologies.

SQZ-PBMC-HPV is a vaccine that uses the Cell Squeeze technology to guide peripheral blood mononuclear cells through a microfluidic chip. Preclinically, the agent demonstrated improvement in MHC-I presentation for human and murine cells and induced robust CD8-positive T cell response, and improve anti-tumor activity compared with other vaccines.

"We are thrilled to receive FDA fast track designation for our SQZ® Antigen Presenting Cells product candidate," said Armon Sharei, PhD, chief executive officer and founder at SQZ Biotechnologies, in a press release. "This designation adds to our exciting clinical data presented at ESMO-IO last year where we first demonstrated the potential of our Cell Squeeze® technology to drive clinical benefit while maintaining favorable tolerability.”

In the phase 1, multicenter, open-label, dose-escalation, and dose-expansion SQZ-PBMC-HPV-101 study (NCT04084951), 12 patients with incurable HPV16-positive cancers progressing after unlimited prior therapy were treated with SQZ-PBMC-HPV in 3 dose cohorts. Notably, 7 of the patients had anal cancer, 3 had head and neck cancer, and 2 had cervical cancer. In 1 cohort of 3 patients, the dosage of SQZ-PBMC-HPV was 0.5 x10e6/kg, 5 patients were treated with 2.5 x10e6/kg, and 4 received 2.5x 10e6/kg.

The patients were treated with a median of 4 prior lines of therapy (range 1-7), and the majority previously received an immune checkpoint inhibitor. Ten patients in the study had metastases to the liver or lung. The median number of doses administered was 3 across all dose cohorts. There was 1 patient who received 10 doses of the agent and remained in the study for 42 weeks.

Ten patients were response evaluable and of those patients, 4 had stable disease per RECIST v1.1. There was also an increase in immune activity in select patients, according to the preliminary tumor analyses conducted before and after therapy.

In terms of safety, SQZ-PBMC-HPV was well-tolerated in the study with no dose-limiting toxicities or grade > 3 serious adverse events. There was 1 patient in cohort 1 who experienced grade 2 infusion-related reaction and cytokine release syndrome.

The study is ongoing and aims to enroll 200 patients to receive SQZ-PBMC-HPV monotherapy or in combination with either atezolizumab (Tecentriq), ipilimumab (Yervoy), or nivolumab (Opdivo). The study is being conducted at 9 sites in the United States (US), including Arizona, California, Colorado, Kansas, Massachusetts, Nebraska, Oklahoma, Oregon, and Tennessee. Eight of the US sites are actively recruiting. Further, 1 site in Canada and 1 in Germany are actively recruiting patients.

The FDA fast program can potentially expedite future review processes and accelerate the registrational path for SQZ-PBMC-HPV."

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