August 7, 2015
By Alex Keown, BioSpace.com Breaking News Staff
NEW YORK --- Pfizer Inc. and Bristol-Myers Squibb Company are revving up research into cancer fighting therapies that accelerate the immune system’s attack, Reuters reported this morning.
Pfizer currently has five Phase I studies underway or in the beginning stages for cancer treatments targeting a protein called 4-1BB. Bristol-Myers is also right behind with its own studies of 4-1BB. Research into antibodies targeting 4-1BB has been on hold since 2008 after early clinical trials conducted by Bristol discovered signs of liver damage. However, recently researchers found lower doses of a 4-1BB antibody were effective as an anti-cancer treatment, Reuters said. When the body’s immune system identifies cancer cells, the 4-1BB protein appears on the surfaces of T-cells to accelerate their attack. Traditional oncology treatments with medications such as Roche ’s Rituxan trigger an immune response in the body, while the accelerator treatment “latches on to the 4-1BB protein and intensifies the response,” Bidnessetc said.
Researchers believe that revisiting immune accelerator therapies could work for several types of cancers, further changing oncology treatments.
An early Pfizer study of 38 patients showed 40 percent of those patients with follicular lymphoma and a third of those with mantle cell lymphoma experienced a reduction in cancer with no serious side effects. Pfizer plans to use the approach in nearly five more early-stage studies, in combination with Merck & Co. ’s PD-1 drug Keytruda and Roche’s Herceptin, Bidnessetc reported.
Bristol Myers oncology research is focused on the development of treatments based on the receptor proteins found on T-cells and in particular, the programmed death receptor, commonly referred to as PD-1. Bristol Myers is organizing six Phase I 4-1BBB studies in conjunction with traditional cancer meds including its own Opdivo and Eli Lilly and Company ’s Erbitux.
Opdivo, approved in March by the U.S. Food and Drug Administration (FDA) for treatment of patients with metastatic squamous non-small cell lung cancer, is an immuno-therapy drug delivered via injection that harnesses the patient’s own immune system to fight cancerous cells.
Opdivo works by inhibiting the cellular pathway known as PD-1 protein on cells that blocks the body’s immune system from attacking cancerous cells. Opdivo is intended for patients who have previously been treated with platinum-based chemotherapy.
Merck’s Keytruda, has been shown effective in treating three kinds of cancers. Keytruda, also known as pembrolizumab, is a humanized monoclonal antibody that blocks the interaction between the protein PD-1 and its ligands, PD-L1 and PD-L2. By binding to the PD-1 receptor and blocking the interaction with the receptor ligands, Keytruda releases the PD-1 pathway-mediated inhibition of the immune response, including the anti-tumor immune response, the company said. PD-1 inhibitors are seen as one of the best opportunities in treating lung cancers.
The success of early results shown by Pfizer has spurred AbbVie and Johnson & Johnson to begin preclinical work on their accelerator candidates, Seeking Alpha noted.
Immuno-oncology is an expanding field with large and small companies, such as Pfizer, AstraZeneca, Bristol-Myers Squibb and Jounce Therapeutics carving out their niche in that area. Immuno-oncology harnesses the body’s own immune system to fight cancer cells. The immuno-oncology field is expected to grow to $40 billion by 2025, a Leerink analysis said.
In June Bristol-Myers presented immuno-oncology data at the American Society of Clinical Oncology (ASCO)’s annual meeting in Chicago, including information from its CHECKMATE 057 trial, a Phase III study of Opdivo versus chemotherapy in second line non-squamous lung cancer. Initial findings demonstrated that the estimated survival rate in evaluable patients was 62 percent at 12 months
