Pemrest 100 mg / 4 ml (Pembrolizumab) | Keytruda Alternative & Price Guide

Description

Pemrest is an intravenous immunotherapy containing pembrolizumab, the same active molecule sold under the brand name Keytruda. Everest Pharmaceuticals manufactures it in Bangladesh under WHO-GMP standards, supplied as a 100mg/4mL single-dose vial.

Pembrolizumab does not attack tumor cells directly. It works on the immune system instead. Cancer cells frequently exploit a receptor called PD-1, which signals nearby T-cells to stand down and leave the tumor alone. Pembrolizumab blocks that signal, and T-cells that could already recognize the cancer are free to act on it again.

The drug is also unusual in how some of its approvals are written. For certain patients, eligibility depends on the tumor’s genetic profile (MSI-High or mismatch repair deficient status) rather than the organ where the cancer began. This was among the first tumor-agnostic approvals in oncology, and it explains why pembrolizumab’s label spans so many different cancer types.

If you are researching Pemrest as an alternative to the originator brand, one point needs stating plainly. Pemrest is not an FDA-approved or EMA-approved biosimilar. No biosimilar pembrolizumab has been approved in either market, because Keytruda remains under patent protection there. Production of patent-protected biologics in Bangladesh is permitted under the WTO’s TRIPS exemption for least-developed countries. We publish this here rather than leave you to discover it later.

Clinical Expert Insight

“Most of my patients arrive knowing pembrolizumab as a lung cancer or melanoma drug. Fewer know it can be prescribed on the basis of a genetic testing result, whatever organ the cancer started in. For someone who has already worked through the standard lines of therapy, that difference matters a great deal.

The counterpart is vigilance. This drug does not act on the tumor. It acts on the immune system, and an activated immune system can turn on healthy tissue. I tell patients that a new symptom deserves a phone call even when it seems unconnected to their cancer, and even when the last infusion was months ago. Breathlessness. Diarrhea that will not settle. Unexplained exhaustion. Those calls are what let us intervene while the problem is still small.”

— Dr. Salma Mamdouh Elreedy, Clinical Oncologist, Sphinx Cure Oncology Center

Pemrest Uses and Clinical Safety Protocols

Precise Indications & Biomarkers

• Biomarker-selected solid tumors: certain non-small cell lung cancers (by PD-L1 Tumor Proportion Score), unresectable or metastatic melanoma, recurrent or metastatic head and neck squamous cell carcinoma, and selected gastric, cervical, hepatocellular, urothelial and Merkel cell carcinomas.
• Hematologic malignancies: classical Hodgkin lymphoma and primary mediastinal large B-cell lymphoma in the relapsed or refractory setting.
• Tumor-agnostic indication: any advanced solid tumor identified as MSI-High, mismatch repair deficient, or high tumor mutational burden, regardless of where the cancer originated.
• Testing requirements: confirmed biomarker testing precedes treatment for most indications. The specific test depends on which indication applies, and results are not interchangeable between them.

Mechanism of Action, Pharmacokinetics & Administration

Pembrolizumab binds the PD-1 receptor on T-cells and blocks both of its ligands, PD-L1 and PD-L2. T-cells already primed against the tumor remain active as a result.

The drug stays in the body a long time. Its terminal half-life is roughly 22 to 27 days, which is why infusions are scheduled three to six weeks apart rather than daily or weekly. The same property explains something patients are rarely warned about: an immune-related side effect can surface months after a final infusion.

Other pharmacokinetic characteristics that shape treatment:

• Absorption: administered intravenously and therefore fully available in the bloodstream immediately. There is no absorption phase.
• Distribution: volume of distribution at steady state is small, approximately 6 to 7.4 L, typical for a therapeutic antibody.
• Metabolism: cleared through the general protein breakdown pathways that handle every antibody in the body. Liver enzymes (CYP450) play no part in its clearance. Hepatic and renal impairment therefore have limited effect on exposure.
• Clearance: low, at approximately 0.2 L per day.

Administration. Pemrest is given as an intravenous infusion over roughly 30 minutes, at a hospital or infusion center, by staff trained to administer it. Standard adult dosing is 200mg every three weeks or 400mg every six weeks. Combination regimens with chemotherapy may follow a different schedule set by the treating team. There is no self-administration, no dose adjustment at home and no missed-dose rule to memorize, since the infusion center holds the schedule. Many protocols cap treatment at around 24 months in patients who are responding well, though your oncologist decides the endpoint in your case.

Adverse Event (AE) Management Table

Chemotherapy side effects tend to follow a pattern patients can anticipate: hair loss, low blood counts, nausea at predictable points in the cycle. Pembrolizumab behaves differently. Because the drug works by reactivating the immune system, the principal risk is that the immune system inflames healthy tissue. This can happen in the lungs, bowel, liver, thyroid, kidneys or skin, and it often develops before you would notice anything yourself. That is why your team will check liver enzymes, creatinine and thyroid function at the start of treatment and at intervals throughout it.

The protocols below reflect general prescribing guidance for PD-1 inhibitors. Your oncologist’s judgment governs actual management.

Table-01: Immune-Mediated Adverse Event Management

Across all categories, treatment resumes only once symptoms settle to Grade 1 or lower and corticosteroids taper to a low maintenance dose within approximately 12 weeks. Where that taper cannot be achieved, treatment is usually stopped permanently.

Clinical Efficacy: The KEYNOTE Benchmarks

• First-line NSCLC (KEYNOTE-024, NCT02142738). This Phase III trial compared pembrolizumab monotherapy against platinum-based chemotherapy in previously untreated patients with PD-L1 TPS of 50% or greater. Five-year follow-up data published in the Journal of Clinical Oncology in 2021 showed overall survival of approximately 32% at five years with pembrolizumab, against approximately 16% with chemotherapy. It was the first Phase III first-line immunotherapy trial in NSCLC to report five-year outcomes.
• Melanoma (KEYNOTE-006). Supported the original approval, demonstrating superior survival against ipilimumab in previously untreated advanced disease.
• Head and neck cancer (KEYNOTE-048). Supported approval in recurrent and metastatic HNSCC, both as monotherapy and combined with chemotherapy.
• Tumor-agnostic MSI-H/dMMR (KEYNOTE-158 and related studies). Supported the biomarker-based approval covering any solid tumor meeting the genetic criteria.

Pembrolizumab’s label covers more indications than any other product in our catalogue, and each approval rests on its own pivotal trial rather than shared data. The FDA approval history page lists them in full.

Interaction & Precaution Matrix

Pembrolizumab has no classic CYP450-mediated drug interactions, and no formal pharmacokinetic interaction studies have identified any. Several treatment-level interactions still matter clinically.

Table-02: Treatment-Level Interaction Considerations

Precautions & Special Populations

• Pregnancy. Pembrolizumab can cause fetal harm based on its mechanism of action. Patients of reproductive potential should use effective contraception during treatment and for at least four months after the final dose.
• Lactation. It is not known whether pembrolizumab passes into breast milk. Breastfeeding is not recommended during treatment or for four months after the final dose.
• Hepatic and renal impairment. Mild to moderate impairment does not usually require a dose change, for the reason set out in the pharmacokinetics section above. Data in severe impairment remains limited, and these patients need closer monitoring.
• Prior transplant history. Requires a joint decision between the oncology and transplant teams before starting.
• Storage. Pemrest must be kept refrigerated at 2°C to 8°C for its entire journey. It must not be frozen or shaken. This is the only product in our catalogue carrying a continuous cold-chain requirement; everything else we ship tolerates room temperature.

Certified Quality & International Distribution

Pemrest (Everest) and Keytruda (Originator) Compared

The table below states only what can be verified today.

Table-03: Product Comparison

Everest Pharmaceuticals Manufacturing

Everest Pharmaceuticals produces Pemrest in a WHO-GMP certified facility with dedicated biologics handling.

Global Access: Named Patient Program (NPP)

Patients in regions where Pemrest is not locally registered may still access it under Named Patient or personal-use importation rules.

• Prescription. A valid prescription and treatment summary from your treating oncologist.
• Documentation. A Letter of Medical Necessity and patient identification.
• Import permit. Our team handles the personal-use import permit application with your local drug authority.
• Logistics. Because Pemrest is a refrigerated biologic, shipment goes through cold-chain-verified couriers with continuous temperature monitoring rather than the standard timeline used for our oral medicines.

Frequently Asked Questions (FAQs)