Corvus Pharmaceuticals announces updated data from Phase 1 study of CPI-006

Corvus Pharmaceuticals announced updated data from its ongoing Phase 1 study investigating the potential for CPI-006 to provide a novel immunotherapy approach for patients with COVID-19. The results demonstrated that all evaluable patients treated in the first two cohorts of the study produced significant titers of antibody to SARS-CoV-2 within seven days of receiving the treatment, with levels of antibody, including neutralizing antibodies, continually increasing out to 28 days. In addition, all of these patients were discharged from the hospital with clinical improvement and none experienced any drug-related safety issues. The study has completed enrollment in the third cohort of five patients, with the overall study expected to enroll up to 30 patients. The open-label, Phase 1 study is expected to enroll up to 30 hospitalized COVID-19 patients with mild to moderate symptoms. Patients will receive a single dose of CPI-006, with levels of 0.3, 1.0, 3.0 and 5.0 mg/kg, escalating in four cohorts as the study progresses. Patients will receive medications, therapies, and interventions per standard treatment protocols for COVID-19 for the duration of the study. The primary efficacy endpoint is the change in serum immunoglobulin anti-SARS-CoV-2 levels compared to baseline at day 28. The study also will examine safety and other clinical endpoints, including time to resolution of symptoms and duration of hospitalization. The Company has submitted a manuscript describing the initial results from the first two cohorts of the study for publication online at medRxiv.org. In the study, the median age of the patients was 64 years and all the patients had comorbidities that increased their COVID-19 risk: diabetes, hypertension, obesity, and/or cancer. The median duration of symptoms prior to treatment with CPI-006 was 8 days. The key highlights from these 10 patients, include: Nine of 9 patients with pre-treatment serum samples available had low pre-treatment levels of anti-SARS-CoV-2 antibodies independent of the duration of their prior COVID-19 symptoms. IgG and IgM antibody titers against the SARS-CoV-2 trimeric spike and/or receptor binding domain increased in 8 of 8 evaluable patients within 7 days of a single infusion of low doses of CPI-006. One patient did not have a pre-treatment serum sample available but had a sample collected one day after receiving CPI-006 and this sample exhibited a high titer, which continued to increase. In five patients measured, the antibodies were neutralizing; one patient with lymphopenia showed a delay in generating neutralizing antibodies. In all patients evaluated, the antibody responses continued to increase out to 28 days post treatment with CPI-006. Rising titers of greater than1:200,000 to spike protein and greater than1:100,000 to RBD were observed. IgM titers also continued to rise reaching levels of 1:100,000 in some patients. One patient continued to have rising titers beyond 56 days with serum titers of IgG both to spike and to RBD of greater than102,000. Neutralizing antibody titers also increased progressively out to 28 days, which was the latest time point available. In one patient tested, memory B cells increased from 1.8% to 4.8% of B cells at 28 days post treatment with CPI-006, with serum IgG titers to spike and to RBD of greater than1:50,000. In three of three patients tested to-date, CD4 and CD8 T effector memory cells increased by day 28 post treatment with CPI-006 and these cells were shown to respond specifically to SARS-CoV-2 viral antigens. All 10 patients were discharged from the hospital with clinical improvement after a median of 4 days. There were no drug-related toxicity or safety issues reported. Additional data from this study is expected to be available in late 2020, including results from the 3.0 and 5.0 mg cohorts and longer follow-up data from the 0.3 and 1.0 mg cohorts. The Company has submitted for a potential presentation of data from this study at the Society for Immunotherapy of Cancer annual meeting in November. In addition, if the study meets its objectives, Corvus intends to work with the FDA to initiate a broader, randomized study that could potentially be adapted into a pivotal study to support a regulatory submission for FDA approval.