Keytruda 100 MG/4 mL (Pembrolizumab)

Basic Product Information of Keytruda 100 MG/4 mL (Pembrolizumab)

How Keytruda 100 MG/4 mL (Pembrolizumab) Works: PD-1 Immune Checkpoint Blockade and Restoration of Antitumor T-Cell Immunity

Pembrolizumab, the active ingredient in Keytruda 100 MG/4 mL, is a humanized IgG4 kappa monoclonal antibody engineered to selectively and with high affinity bind to the PD-1 (Programmed Death-1) receptor expressed on the surface of activated T lymphocytes, natural killer (NK) cells, and B cells. PD-1 is an inhibitory immune checkpoint receptor: when engaged by its ligands PD-L1 (CD274) or PD-L2 (CD273) which are upregulated on tumor cells, tumor-associated macrophages, and stromal cells across a wide range of solid tumors and hematologic malignancies PD-1 transmits inhibitory signals through its cytoplasmic ITIM (immunoreceptor tyrosine-based inhibitory motif) and ITSM (immunoreceptor tyrosine-based switch motif) domains that suppress T-cell activation, proliferation, cytokine production (IFN-γ, TNF-α, IL-2), and cytotoxic effector function (perforin/granzyme-mediated tumor cell killing).

Tumors exploit this physiological tolerance mechanism to create an immunosuppressive microenvironment that enables immune evasion despite the presence of tumor-reactive T-cell clones capable of recognizing tumor-associated neoantigens. Pembrolizumab blocks PD-1’s interaction with both PD-L1 and PD-L2 with picomolar binding affinity (KD ≈1 nM), restoring the functional activation, clonal expansion, and cytotoxic capacity of exhausted and suppressed tumor-infiltrating lymphocytes (TILs) generating a durable, antigen-specific antitumor immune response not dependent on the tumor’s intrinsic proliferative or survival pathways.

This mechanism of immune restoration, rather than direct cytotoxic pharmacology, distinguishes pembrolizumab from conventional chemotherapy and targeted kinase inhibitors: pembrolizumab does not kill tumor cells directly; instead, it removes the immunological brake that prevents the host immune system from eliminating them. Oncology treatment providers sourcing pembrolizumab medicines for their clinical programs can browse the complete pembrolizumab collection at Mediaid Pharmacy.

At the clinical dose of 200 mg administered as a 30-minute intravenous (IV) infusion every 3 weeks (Q3W) or 400 mg every 6 weeks (Q6W) as the alternative flat-dose regimen pembrolizumab achieves near-complete and sustained PD-1 receptor occupancy on peripheral blood T cells, with pharmacokinetic modeling from the KEYNOTE clinical program demonstrating that steady-state pembrolizumab exposures at 200 mg Q3W produce receptor occupancy above the 95% saturation threshold throughout the entire dosing interval.

The pharmacokinetic profile of pembrolizumab follows a two-compartment model with time-dependent clearance: the geometric mean steady-state peak (Cmax) is approximately 90.7 μg/mL, the trough (Cmin) approximately 21.3 μg/mL, and the estimated terminal half-life approximately 27 days consistent with the prolonged target-mediated disposition expected for a high-affinity IgG4 monoclonal antibody operating at the picomolar KD of PD-1 binding. The IgG4 isotype of pembrolizumab was deliberately selected to minimize Fc-mediated effector functions (antibody-dependent cellular cytotoxicity [ADCC] and complement-dependent cytotoxicity [CDC]) against PD-1-expressing T cells themselves, as IgG4 carries substantially reduced FcγR binding affinity relative to IgG1 preserving the T-cell populations that pembrolizumab must activate rather than deplete.

A stabilizing S228P hinge mutation was introduced to prevent IgG4 Fab-arm exchange (half-antibody formation), ensuring pembrolizumab remains a bivalent, monospecific antibody throughout its systemic exposure period. Healthcare providers and distributors seeking the full range of oncology medicines available at Mediaid Pharmacy can browse the complete oncology portfolio for consolidated procurement and worldwide delivery.

The PD-L1 expression level in tumor tissue, quantified using the Tumor Proportion Score (TPS) the percentage of viable tumor cells with membrane PD-L1 staining at any intensity and the Combined Positive Score (CPS) the number of PD-L1-staining cells (tumor cells, lymphocytes, macrophages) divided by total viable tumor cells, multiplied by 100 is the primary predictive biomarker for pembrolizumab monotherapy efficacy across multiple indications. In NSCLC, the KEYNOTE-024 trial demonstrated that pembrolizumab monotherapy significantly outperformed platinum-based chemotherapy exclusively in the PD-L1 TPS ≥50% population (median PFS 10.3 vs 6.0 months; HR 0.50; p<0.001), establishing TPS ≥50% as the selection criterion for first-line pembrolizumab monotherapy in NSCLC.

In HNSCC (KEYNOTE-048, n=882), pembrolizumab monotherapy demonstrated superior OS versus EXTREME regimen (cetuximab + platinum + 5-FU) in the CPS ≥20 (median OS 14.9 vs 10.7 months; HR 0.61; p=0.0007) and CPS ≥1 subgroups (median OS 12.3 vs 10.3 months; HR 0.78; p=0.0086), while pembrolizumab combined with platinum + 5-FU demonstrated superior OS in the total population. In MSI-H/dMMR solid tumors, pembrolizumab demonstrates tumour-agnostic efficacy independent of PD-L1 expression, with the KEYNOTE-158 basket trial (n=1,066; 10 tumour types) showing an objective response rate (ORR) of 34.3% (95% CI: 28.3–40.8) across all MSI-H cohorts establishing the first tissue/site-agnostic oncology approval based solely on a molecular biomarker across tumor histologies. Oncologists sourcing Keytruda 100 MG/4 mL Pembrolizumab from China-market packaging can access the complete solid tumors medicines portfolio at Mediaid Pharmacy for comprehensive oncology procurement.

Approved Indications of Keytruda 100 MG/4 mL (Pembrolizumab) Reference Label and China NMPA-Registered Indications

Pembrolizumab, the active ingredient in Keytruda 100 MG/4 mL, carries regulatory approvals across an exceptional breadth of oncology indications the widest indication portfolio of any single approved anti-PD-1 immunotherapy. Indications span both monotherapy settings (as first-line, second-line, or subsequent therapy based on biomarker selection) and combination regimens (with platinum-based chemotherapy, anti-VEGF/VEGFR agents, anti-CTLA-4 antibodies, antibody-drug conjugates, and PARP inhibitors). The China NMPA-approved label for Keytruda (可瑞达) covers several of the major tumor types listed below; prescribers should confirm the currently approved China indications on the Keytruda China NMPA product label before initiating treatment, as locally registered indications may differ from the global FDA/EMA reference label.

Key Clinical Benefits of Keytruda 100 MG/4 mL (Pembrolizumab)

Drug Interactions and Important Safety Information for Keytruda 100 MG/4 mL (Pembrolizumab)

The clinically most significant drug interactions for pembrolizumab involve immunosuppressive agents, systemic corticosteroids, other immune checkpoint inhibitors, and agents whose toxicity profiles overlap with immune-mediated adverse reactions (imAEs). Pembrolizumab is a large IgG4 monoclonal antibody eliminated through proteolytic catabolism not through hepatic CYP enzymes, renal glomerular filtration, or P-glycoprotein transporters meaning that pembrolizumab carries no pharmacokinetic drug-drug interactions (DDIs) via CYP3A4, CYP2D6, CYP2C9, UGT1A, or P-gp pathways.

All clinically relevant pembrolizumab interactions are therefore pharmacodynamic: they arise from overlapping, opposing, or compounding immunological mechanisms rather than from metabolic enzyme competition, and they require clinical management decisions (dose adjustment, prophylactic medications, monitoring intensification, or co-therapy avoidance) rather than pharmacokinetic dose recalculation. Because Keytruda 100 MG/4 mL is supplied in China-market packaging, oncology treatment teams should additionally consult the locally registered prescribing information and any China NMPA-issued safety communications for current pharmacovigilance guidance. For the complete range of oncology medicines available at Mediaid Pharmacy, including companion immunotherapy agents and supportive care medicines, browse the full oncology portfolio.

Systemic corticosteroids and immunosuppressive agents represent the highest-priority pharmacodynamic interaction class. High-dose systemic corticosteroids (prednisone >10 mg/day equivalent) administered concomitantly with pembrolizumab at the time of treatment initiation attenuate T-cell activation and suppress the CD8+ cytotoxic T-lymphocyte (CTL) expansion that PD-1 blockade depends on for antitumor efficacy, with retrospective KEYNOTE clinical program analyses demonstrating that baseline corticosteroid use (≥10 mg prednisone equivalent) is associated with significantly inferior pembrolizumab PFS and OS outcomes across NSCLC and melanoma cohorts.

Accordingly, systemic corticosteroids at immunosuppressive doses should be avoided before pembrolizumab initiation; however, physiological replacement doses (≤10 mg prednisone equivalent daily), short-course steroid premedication for chemotherapy-combination regimens (dexamethasone antiemetic prophylaxis), and inhaled or topical steroids do not meaningfully attenuate pembrolizumab efficacy. Paradoxically, systemic corticosteroids are the first-line treatment for managing pembrolizumab-induced immune-mediated adverse reactions (imAEs): Grade 2 pneumonitis, colitis, hepatitis, nephritis, and endocrinopathies are treated with prednisone 1–2 mg/kg/day, with dose tapering over ≥4–6 weeks once symptoms improve to Grade 1 or below.

Other immune checkpoint inhibitors (anti-CTLA-4 antibodies: ipilimumab, tremelimumab; anti-PD-L1 antibodies: atezolizumab, durvalumab, avelumab) potentiate pembrolizumab’s immune-activating mechanism, substantially increasing the rate and severity of imAEs including Grade 3/4 immune-mediated colitis (incidence 13–16% with pembrolizumab + ipilimumab combination vs ≤2% with either agent alone) and require careful benefit-risk assessment and intensified imAE monitoring protocols when co-administered in combination regimens. For MSD-branded companion oncology agents available at Mediaid Pharmacy, explore the MSD oncology medicines section.

Antineoplastic agents combined with pembrolizumab in KEYNOTE regimens including pemetrexed, carboplatin, paclitaxel, nab-paclitaxel, cisplatin, 5-fluorouracil, gemcitabine, and trastuzumab carry combinatorial toxicity profiles that require proactive monitoring. Platinum-based agents combined with pembrolizumab increase the risk of renal toxicity (acute kidney injury) and peripheral neuropathy while sharing overlapping immune-mediated nephritis risk with pembrolizumab; renal function (serum creatinine, eGFR) must be monitored at each cycle. Taxanes combined with pembrolizumab increase peripheral neuropathy risk; pembrolizumab-induced Grade 2+ peripheral neuropathy must be distinguished from taxane neuropathy in combination regimens.

Lenvatinib (anti-VEGFR/FGFR TKI) combined with pembrolizumab in endometrial carcinoma and RCC produces overlapping hypertension, proteinuria, hepatotoxicity, and fatigue toxicities that require vigilant multi-toxicity monitoring; lenvatinib dose reductions are permitted by the KEYNOTE-775 and KEYNOTE-581 (CLEAR) protocols without pembrolizumab dose reduction, as pembrolizumab is administered at fixed flat-dose without weight-based adjustment. Opioid analgesics used for cancer pain management should be reviewed for potential pharmacodynamic interaction with pembrolizumab-induced immune-mediated endocrinopathies: adrenal insufficiency induced by pembrolizumab may significantly alter opioid metabolism via cortisol-dependent CYP enzyme regulation, necessitating opioid dose review if adrenal insufficiency is diagnosed during pembrolizumab treatment.

All patients receiving Keytruda 100 MG/4 mL must provide complete medication lists to their treating oncologist before each infusion cycle, including prescription, over-the-counter, herbal supplement, and traditional medicine use, as interactions with immunologically active traditional medicines used in Asian markets are incompletely characterized. For the complete pembrolizumab injection options available with worldwide shipping, visit Mediaid Pharmacy.

Side Effects and Precautions of Keytruda 100 MG/4 mL (Pembrolizumab)

Who Should Use Keytruda 100 MG/4 mL (Pembrolizumab)?

Keytruda 100 MG/4 mL (Pembrolizumab) is indicated for adult patients with advanced or metastatic solid tumors and hematologic malignancies across the NMPA-approved (China) and global reference-label indications described above, administered by qualified oncology healthcare professionals in a clinical setting equipped for the management of severe immune-mediated adverse reactions, including IV corticosteroid infusion, emergency immunosuppressive therapy, and intensive care escalation where required.

Biomarker-selected patient populations who derive the greatest benefit from pembrolizumab monotherapy include: patients with metastatic NSCLC and PD-L1 TPS ≥50% (first-line monotherapy, KEYNOTE-024/042); patients with HNSCC and PD-L1 CPS ≥20 or CPS ≥1 (first-line monotherapy, KEYNOTE-048); patients with advanced MSI-H/dMMR tumors across all histologies (KEYNOTE-158, KEYNOTE-177); patients with advanced TMB-H (≥10 mut/Mb) solid tumors after prior therapy (KEYNOTE-158); patients with unresectable or metastatic melanoma (first- and second-line; no mandatory biomarker requirement); and patients with urothelial carcinoma ineligible for cisplatin and with PD-L1 CPS ≥10 (first-line monotherapy, KEYNOTE-052).

Combination-regimen patient populations include metastatic non-squamous and squamous NSCLC regardless of PD-L1 (KEYNOTE-189, KEYNOTE-407); metastatic TNBC with PD-L1 CPS ≥10 or high-risk early TNBC (KEYNOTE-522); advanced endometrial carcinoma after prior platinum (KEYNOTE-775 with lenvatinib); metastatic RCC (KEYNOTE-426 with axitinib; KEYNOTE-581 CLEAR with lenvatinib); and gastric/GEJ cancer HER2-positive (KEYNOTE-811 with trastuzumab + chemotherapy) or CPS ≥10 (first-line pembrolizumab + chemotherapy).

Absolute contraindications to Keytruda 100 MG/4 mL include: known hypersensitivity to pembrolizumab or any formulation excipient (anaphylaxis/Grade 4 hypersensitivity); Grade 4 immune-mediated adverse reactions (excluding endocrinopathies controlled with hormone replacement); and recurrent Grade 3 immune-mediated reactions. Patient populations requiring careful pre-treatment benefit-risk assessment include: patients with active autoimmune disease requiring systemic immunosuppression; patients with prior allogeneic transplant; patients receiving chronic corticosteroid therapy at immunosuppressive doses; patients with active systemic infections; and patients with ECOG PS ≥3 (who were largely excluded from KEYNOTE trials and for whom pembrolizumab benefit is not established).

For oncology providers sourcing Keytruda 100 MG/4 mL (Pembrolizumab) in China-market packaging or seeking consolidated procurement of MSD oncology medicines alongside companion supportive care agents, the Mediaid Pharmacy MSD medicines portfolio and the complete oncology medicines collection are available with worldwide delivery.

Global Supplier: Mediaid Pharmacy Worldwide Shipping for Keytruda 100 MG/4 mL (Pembrolizumab)

Mediaid Pharmacy is a Dhaka-based supplier of specialty oncology and original molecule medicines with worldwide shipping to patients, oncology clinics, hospitals, cancer centers, and pharmaceutical distributors across all regions. Keytruda 100 MG/4 mL (Pembrolizumab), manufactured by MSD (Merck Sharp & Dohme) in China-market packaging (可瑞达), is available as 2 vials per box, supplied with pricing quotations, stock confirmation, full product documentation, and end-to-end international cold-chain delivery tracking for every order maintaining the 2°C to 8°C storage requirement across all international shipment legs.

Oncology treatment centers, hospital pharmacy departments, cancer research institutes, distributors, and individual patients can contact the Mediaid Pharmacy team through WhatsApp, phone, or WeChat for all inquiries about Keytruda 100 MG/4 mL Pembrolizumab stock availability, current pricing, and international delivery timelines to their specific country. Buyers sourcing pembrolizumab in China-market packaging, establishing institutional anti-PD-1 immunotherapy supply programs, or co-sourcing multiple oncology medicines in a single consolidated international shipment can browse the complete pembrolizumab medicines collection and the broader oncology medicines portfolio at Mediaid Pharmacy before submitting a consolidated quotation request.

Why Choose Keytruda 100 MG/4 mL (Pembrolizumab) from Mediaid Pharmacy?

Keytruda 100 MG/4 mL (Pembrolizumab) from Mediaid Pharmacy gives oncology treatment teams access to the world’s most broadly approved anti-PD-1 immune checkpoint inhibitor an original molecule medicine by MSD (Merck) that has generated definitive Phase 3 survival data across more tumor types than any other single oncological immunotherapy. Pembrolizumab’s 5-year OS rate of 31.9% in PD-L1-high advanced NSCLC (KEYNOTE-024), its tumor-agnostic MSI-H/dMMR approval spanning 10+ cancer histologies (KEYNOTE-158), its landmark superior OS in first-line HNSCC CPS ≥20 (KEYNOTE-048), and its neoadjuvant/adjuvant pCR improvement in early TNBC (KEYNOTE-522) collectively establish pembrolizumab as the anchor immunotherapy agent in evidence-based oncology practice across solid tumors.

The 100 mg/4 mL vial formulation (25 mg/mL) packaged as 2 vials per box in China-market packaging (可瑞达) supplies a standard 200 mg flat-dose infusion cycle (Q3W) from two vials per cycle, providing a clearly defined supply unit for both 200 mg Q3W and 400 mg Q6W dosing schedules. The flat-dose non-weight-based dosing of pembrolizumab (200 mg Q3W or 400 mg Q6W, regardless of body weight) supported by population pharmacokinetic modeling from over 2,000 patients in the KEYNOTE program eliminates dose calculation variability, simplifies pharmacy compounding, and reduces preparation error risk in institutional oncology pharmacy settings.

Mediaid Pharmacy supplies Keytruda 100 MG/4 mL Pembrolizumab with full product documentation, cold-chain shipping compliance, specialist supply support, and worldwide delivery from Dhaka. To source additional MSD oncology medicines or a complete immunotherapy and targeted therapy panel alongside Keytruda, visit the Mediaid Pharmacy MSD medicines section and the solid tumors medicines portfolio, and contact the team for a personalized procurement quotation.

Frequently Asked Questions About Keytruda 100 MG/4 mL (Pembrolizumab)