MedImmune inked an in-license agreement with Pfizer for tremelimumab, a mAb therapeutic for various types of cancer. Pfizer presented final toxicity results of a Phase I dose-escalation trial of tremelimumab in combination with gemcitabine in chemotherapy-naive patients with metastatic pancreatic cancer.
Under terms of the deal MedImmune will assume global development rights to tremelimumab. Pfizer retains rights to use the drug compound with specified types of combination therapies.
Pfizer previously signed over developments rights covering tremelimumab in melanoma to Debiopharm after the mAb failed in a Phase III melanoma trial. The interim analysis found that it would not offer any benefit over standard chemotherapy. Thus in April 2008, Pfizer was forced to halt the trial.
A full evaluation of the data revealed a biomarker that predicted patients who were more likely to respond, according to Pfizer. Debiopharm will be responsible for conducting a new Phase III study that leverages this marker to select patients with unresectable, stage IV melanoma. At the time of inking the deal with Debiopharm, Pfizer said it would retain all commercial rights.
Tremelimumab is a fully human mAb that binds to the protein CTLA-4, expressed on the surface of activated T lymphocytes. "Adding another immunotherapeutic approach to our oncology pipeline, one which may employ the immune system itself to fight cancer, exemplifies our continued commitment to embracing this new era of cancer care," says Bahija Jallal, Ph.D., MedImmune's evp, R&D.
MedImmune has seven clinical-stage mAb programs for cancer treatment. Phase I candidates bind to CEA and CD3, CD22, IGF, CD19, and Ang2. The Phase II candidate targets PDGFRα and is being tested in lung cancer and glioblastoma. The company believes that the platelet-derived growth factor receptor alpha (PDGFRα) pathway, with its potential role in regulating transformation as well as tumor microenvironment, progression, and metastasis, may be an important cancer target.
MEDI-575 is a fully human mAb to PDGFRα being tested in lung cancer. It has been shown to inhibit signaling from PDGFRα on cancer cells and supportive stroma. However, MEDI-575 reportedly does not inhibit PDGFRβ, the inhibition of which has been associated with significant clinical toxicities including extravascular fluid accumulation.
MEDI-575 is a fully human mAb to PDGFRα being evaluated as a treatment for glioblastoma multiforme. MEDI-575 has been shown to inhibit signaling from PDGFRα on cancer cells and supportive stroma but not PDGFRβ, MedImmune says.