Anti-PD-1 monoclonal antibody (specialist) Pregnancy: Can cause fetal harm based on its mechanism of action; there are no available data in pregnant women. Human IgG4 immunoglobulins cross the placenta, so dostarlimab may be transmitted from mother to fetus; blockade of PD-1/PD-L1 signalling disrupts tolerance to the fetus in animal models, so potential risks include increased rates of abortion or stillbirth. Advise women of the potential risk to a fetus and of the need for effective contraception (US PI 8.1, 5.4)

Dostarlimab

Brand names: Jemperli

Dostarlimab is a monoclonal antibody immune checkpoint inhibitor used in certain advanced cancers, including endometrial cancer with mismatch-repair deficiency.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 500 mg for the first phase of treatment, then 1,000 mg thereafter

Route: Intravenous infusion over 30 minutes, after dilution

Frequency: 500 mg every 3 weeks (for 6 cycles in combination with carboplatin and paclitaxel, or for 4 cycles as a single agent), followed by 1,000 mg every 6 weeks for all cycles thereafter

NO UK SPC WAS AVAILABLE IN THIS SOURCE BUNDLE - the whole entry is from the US JEMPERLI prescribing information and must be verified against the UK SPC before publication. Indication-specific regimens exactly as stated in the US label: (1) Adults with primary advanced or recurrent endometrial cancer - 500 mg every 3 weeks for 6 cycles in combination with carboplatin and paclitaxel, followed by 1,000 mg monotherapy every 6 weeks for all cycles thereafter; give dostarlimab before carboplatin and paclitaxel when administered on the same day; continue until disease progression, unacceptable toxicity, or up to 3 years. (2) Adults with dMMR recurrent or advanced endometrial cancer, and adults with dMMR recurrent or advanced solid tumours - 500 mg every 3 weeks for 4 cycles, followed by 1,000 mg every 6 weeks for all cycles thereafter, until disease progression or unacceptable toxicity. Patient selection for single-agent use is based on the presence of dMMR in tumour specimens; in high-grade glioma it is recommended to test the primary tumour specimen obtained before temozolomide chemotherapy. NO DOSE REDUCTIONS of dostarlimab are recommended - manage toxicity by withholding or permanently discontinuing. In general withhold for severe (Grade 3) immune-mediated adverse reactions and permanently discontinue for life-threatening (Grade 4) reactions, recurrent severe (Grade 3) reactions requiring systemic immunosuppression, or inability to reduce corticosteroid to 10 mg or less of prednisone equivalent per day within 12 weeks of starting steroids. Specific modifications include: pneumonitis Grade 2 withhold, Grade 3/4 or recurrent Grade 2 permanently discontinue; colitis Grade 2 or 3 withhold, Grade 4 discontinue; myocarditis Grade 2, 3 or 4 permanently discontinue; nephritis Grade 2 or 3 creatinine rise withhold, Grade 4 discontinue; confirmed SJS, TEN or DRESS permanently discontinue; infusion-related reactions Grade 1 or 2 interrupt or slow the infusion rate, Grade 3 or 4 permanently discontinue. Paediatric: safety and efficacy have not been established in paediatric patients.

Dose auto-extracted from US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

None stated (US prescribing information section 4: "None")

Side effects

With carboplatin and paclitaxel in endometrial cancer (>=20%): decreased haemoglobin, increased creatinine, peripheral neuropathy, decreased white cell count, fatigue, nausea, alopecia, decreased platelets, increased glucose, decreased lymphocytes
As a single agent in dMMR solid tumours (>=20%): fatigue/asthenia, anaemia, diarrhoea and nausea
Severe and fatal immune-mediated adverse reactions in any organ system - pneumonitis, colitis, hepatitis, endocrinopathies, nephritis with renal dysfunction, dermatologic reactions and solid organ transplant rejection
Infusion-related reactions
Fatal and other serious complications of allogeneic haematopoietic stem cell transplantation before or after PD-1/PD-L1 blockade

Clinical monograph

How it works

It binds the programmed death-1 (PD-1) receptor on T cells, blocking its interaction with PD-L1 and PD-L2 and restoring T-cell-mediated antitumour immune responses.

Prescribing in practice

It can cause immune-related adverse effects affecting any organ system, including the lungs, bowel, liver and endocrine glands, which may be severe and require corticosteroids and treatment interruption.
Mismatch-repair or microsatellite-instability status guides patient selection for the relevant indications.
It is given by intravenous infusion under specialist oncology supervision.

Monitoring

Monitor for immune-related adverse reactions, including liver, thyroid, adrenal, lung and bowel involvement, before and during treatment.

Counselling the patient

Report new or worsening symptoms such as diarrhoea, cough, breathlessness, rash or unusual tiredness promptly.
Carry an alert that you are receiving immunotherapy so other clinicians are aware.

Evidence & guidelines

Dostarlimab is supported by trial evidence in mismatch-repair-deficient tumours and is appraised by NICE within its licensed indications.

Reference: NICE TA779; ESMO; SmPC; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Cemiplimab · Anti-PD-1 monoclonal antibody (specialist)

Pathways