Ipilimumab: a novel immunostimulatory monoclonal antibody for the treatment of cancer.

Ipilimumab (Yervoy, developed by Medarex and Bristol-Myers Squibb) is a fully human monoclonal IgG1κ antibody against the cytotoxic T-lymphocyte antigen-4 (CTLA-4), an immune-inhibitory molecule expressed in activated T cells and in suppressor T regulatory cells. Interaction of the monoclonal antibody with CTLA-4 blocks inhibitory signals generated through this receptor and enhances T cell activation, leading to increased antitumor responses. Ipilimumab has been approved by FDA in March 2011 as monotherapy (3mg/kg every 3 weeks for 4 doses) for the treatment of advanced (unresectable or metastatic) melanoma both in pre-treated or chemotherapy naïve patients. Four months later, ipilimumab has received a rapid approval by the European Commission, after a positive opinion from the Committee for Medicinal Products for Human Use. However, the indication in the EU is limited to previously-treated patients with advanced melanoma. Ipilimumab is the first agent that has demonstrated to improve overall survival in patients with metastatic melanoma, which has a very poor prognosis, in randomized phase III clinical trials. The patterns of tumour response to ipilimumab differ from those observed with cytotoxic chemotherapeutic agents, since patients may have a delayed yet durable response and obtain long-term survival benefit despite an initial tumour growth. The major draw-back of ipilimumab is the induction of immune-related adverse effects; the latter can be life-threatening, unless promptly managed with immunosuppressive agents (most frequently corticosteroids) according to specific guidelines. Further development of ipilimumab includes its use in the neoadjuvant or adjuvant high-risk melanoma setting and for the treatment of other refractory and advanced solid tumours, either as single agent or in combination with additional immunostimulating agents or molecularly targeted therapies.

Graziani G ，Tentori L ，Navarra P 《-》

The European Medicines Agency review of ipilimumab (Yervoy) for the treatment of advanced (unresectable or metastatic) melanoma in adults who have received prior therapy: summary of the scientific assessment of the Committee for Medicinal Products for Hum

On 13 July 2011 the European Commission issued a marketing authorisation valid throughout the European Union (EU) for ipilimumab for the treatment of advanced (unresectable or metastatic) melanoma in adults who have received prior therapy. Ipilimumab is a monoclonal antibody that specifically blocks the inhibitory signal of cytotoxic T lymphocyte antigen 4 (CTLA-4), resulting in T cell activation, proliferation and lymphocyte infiltration into tumours, leading to tumour cell death. The recommended induction regimen of ipilimumab is 3mg/kg administered intravenously over a 90 min period every 3 weeks for a total of four doses. In a phase 3 trial in patients with advanced melanoma, median overall survival for ipilimumab was 10 months versus 6 months for gp100, an experimental melanoma vaccine (Hazard ratio (HR) 0.66; 95% confidence interval (CI): 0.51, 0.87; p = 0.0026). Ipilimumab was most commonly associated with adverse reactions resulting from increased or excessive immune activity. Most of these, including severe reactions, resolved following initiation of appropriate medical therapy or withdrawal of ipilimumab. The most common side-effects (affecting more than 10% of patients) were diarrhoea, rash, pruritus, fatigue, nausea, vomiting, decreased appetite and abdominal pain. The objective of this paper is to summarise the scientific review of the application leading to approval in the EU. The detailed scientific assessment report and product information, including the summary of product characteristics (SmPC), are available on the European Medicines Agency (EMA) website (www.ema.europa.eu).

Hanaizi Z ，van Zwieten-Boot B ，Calvo G ，Lopez AS ，van Dartel M ，Camarero J ，Abadie E ，Pignatti F ... -  《-》

Ipilimumab: unleashing the power of the immune system through CTLA-4 blockade.

Malignant melanoma is rising faster in incidence than any other malignancy. Long-term remission or "cure" is rare and is almost exclusively limited to therapies that stimulate an immune antitumor response. Ipilimumab is a novel targeted human immunostimulatory monoclonal antibody that blocks cytotoxic T-lymphocyte antigen4 (CTLA-4), an immune-inhibitory site expressed on activated T cells. Ipilimumab is well tolerated as an outpatient infusion therapy. Multiple studies have confirmed significant antimelanoma activity. A randomized trial has documented a survival benefit when ipilimumab was compared to a gp-100 vaccine only arm. The unique mechanism of action of ipilimumab makes assessment of response by conventional criteria difficult. Benefit from ipilimumab can occur after what would be considered progression with World Health Oganization (WHO) or Response Evaluation Criteria in Solid Tumors (RECIST) criteria. New immune response criteria have been proposed. Therapeutic responses peak between 12 and 24 weeks, with slow responses continuing up to and beyond 12 months. The major drug- related adverse side effects (10%-15% grade 3 or above) are immune-related and consist most commonly of rash, colitis, hypophysitis, thyroiditis, and hepatitis. Colonic perforation can occur and patients with diarrhea have to be monitored carefully with strict adherence to treatment algorithms. Algorithms for the treatment of other adverse side effects have been developed. The treatment of immune-related side effects with immunosuppressive agents, such as corticosteroids, does not appear to impair antitumor response. With proper monitoring and management of side effects, ipilimumab is an extremely safe drug to administer. The benefits of ipilimumab will most certainly extend to other malignancies in the near future.

Boasberg P ，Hamid O ，O'Day S 《-》

Development of ipilimumab: contribution to a new paradigm for cancer immunotherapy.

Identification of cytotoxic T-lymphocyte antigen-4 (CTLA-4) as a key negative regulator of T-cell activity led to development of the fully human, monoclonal antibody ipilimumab to block CTLA-4 and potentiate antitumor T-cell responses. Animal studies first provided insight into the ability of an anti-CTLA-4 antibody to cause tumor regression, particularly in combination regimens. Early clinical studies defined ipilimumab pharmacokinetics and possibilities for combinability. Phase II trials of ipilimumab in advanced melanoma showed objective responses, but a greater number of patients had disease stabilization. In a phase III trial, ipilimumab was the first agent to demonstrate an improvement in overall survival in patients with previously treated, advanced melanoma. The adverse event profile associated with ipilimumab was primarily immune-related. Adverse events can be severe and life-threatening, but most were reversible using treatment guidelines. Ipilimumab monotherapy exhibits conventional and new patterns of activity in advanced melanoma, with a delayed separation of Kaplan-Meier survival curves. The observation of some new response patterns with ipilimumab, which are not captured by standard response criteria, led to novel criteria for the evaluation of immunotherapy in solid tumors. Overall, lessons from the development of ipilimumab contributed to a new clinical paradigm for cancer immunotherapy evolved by the Cancer Immunotherapy Consortium.

Hoos A ，Ibrahim R ，Korman A ，Abdallah K ，Berman D ，Shahabi V ，Chin K ，Canetta R ，Humphrey R ... -  《-》

Ipilimumab: an anti-CTLA-4 antibody for metastatic melanoma.

Lipson EJ ，Drake CG 《-》