Pembrolizumab, known by its brand name Keytruda, is a treatment option for certain types of bladder cancer. This medication is an immunotherapy. Its purpose in cancer treatment is to harness the body’s own immune system to identify and combat cancer cells.
This approach offers a different strategy compared to traditional treatments by working with the body’s natural defenses. Understanding such advanced therapeutic options is important for individuals facing a bladder cancer diagnosis.
Understanding Immunotherapy
Pembrolizumab functions as an immune checkpoint inhibitor. The body’s immune system, specifically T-cells, are designed to detect and eliminate abnormal cells, including cancer. However, cancer cells often develop ways to evade this immune response. One common evasion tactic involves a protein called PD-L1 on the surface of cancer cells.
This PD-L1 protein can bind to a receptor called PD-1, located on immune T-cells. When PD-L1 binds to PD-1, it sends an inhibitory signal that turns off the T-cell, preventing it from attacking the cancer cell. Pembrolizumab works by blocking the PD-1 receptor on T-cells. By blocking this interaction, pembrolizumab removes the “brakes” on the immune system, allowing T-cells to reactivate and recognize the cancer cells as foreign, initiating an immune attack against the tumor.
Approved Applications
Pembrolizumab is approved for use in specific situations involving urothelial carcinoma. One application is for non-muscle invasive bladder cancer (NMIBC) that has not responded to Bacillus Calmette-Guérin (BCG) therapy. This includes high-risk NMIBC with carcinoma in situ, especially for patients who are not candidates for or choose not to undergo surgical removal of the bladder.
The medication is also approved for locally advanced or metastatic urothelial carcinoma. In these cases, it can be used after platinum-containing chemotherapy has failed. Additionally, it is an option for patients with advanced urothelial carcinoma who cannot receive cisplatin-based chemotherapy. Pembrolizumab can be used as a single agent or in combination with other drugs, depending on the cancer’s stage and characteristics.
The Treatment Journey
Pembrolizumab is administered as an intravenous (IV) infusion. Each infusion session takes about 30 minutes. The frequency of infusions can vary, given every three or six weeks, based on the treatment plan developed by the healthcare team.
Patients may experience common side effects, such as fatigue, muscle or joint pain, skin rash, and nausea. Other reported effects include diarrhea, decreased appetite, and itching. Patients should communicate any new or worsening symptoms to their healthcare provider.
Immune-related adverse events (irAEs) are a potential aspect of immunotherapy. These occur when the reactivated immune system attacks healthy tissues in the body. Examples of irAEs include inflammation of the lungs (pneumonitis), colon (colitis), liver (hepatitis), or hormone glands (endocrinopathies). Patients are advised to report any unusual symptoms promptly, as early identification and management are important. Management often involves systemic corticosteroid therapy to suppress the immune response, with the dosage adjusted based on the severity of the reaction.
Anticipated Outcomes
Treatment with pembrolizumab can lead to responses in some individuals with bladder cancer. The effectiveness of the treatment can vary among patients, and not everyone will experience the same level of response. Clinical trials have shown that some patients achieve a complete or partial response.
Response to treatment is monitored through medical scans to assess changes in tumor size and activity. Treatment decisions are highly personalized. An oncology team considers the patient’s overall health, cancer stage, and other factors when determining the most suitable treatment plan. Open communication with healthcare providers about expectations and concerns allows for a shared understanding of the potential benefits and risks of pembrolizumab.