Lumakras (Sotorasib): Uses, Side Effects and Dosage

Cancer treatment has changed significantly over time. Traditional chemotherapy can help control cancer, but it also has limitations and may affect healthy cells. Because of this, researchers have increasingly focused on developing targeted therapies that are designed around the molecular or genetic features of a tumour. By acting on specific pathways that drive cancer growth, these treatments offer a more precise approach and may affect healthy cells less than conventional chemotherapy.¹ One of these targeted drugs is Lumakras (sotorasib), a specialized medicine for cancers with a particular mutation.²

What is Lumakras?

Lumakras is a prescription cancer medicine that targets a specific mutation called KRAS G12C found in the DNA of some cancer cells. It was approved for use in adults whose cancer has this mutation and who have already had at least one prior systemic therapy (like chemotherapy).²

The drug comes in tablets that are taken by mouth once daily. It’s not suitable for people whose tumours don’t carry the KRAS G12C change.²

How Lumakras Works (KRAS G12C Inhibitor)

The KRAS gene plays a role in cell growth signals. When it’s mutated to G12C, it can become “stuck” in an active state, driving cancer cell growth. Lumakras binds to the mutant KRAS G12C protein and locks it in an inactive form, slowing or stopping the cancer’s growth signals. That’s why it’s called a KRAS G12C inhibitor.²

Lumakras Uses (Who It’s For)

Lumakras is mainly prescribed to adult patients with locally advanced or metastatic non-small cell lung cancer (NSCLC) that has the KRAS G12C mutation, and who have received at least one prior systemic therapy.²

It may also be used with another targeted therapy called panitumumab for certain cases of KRAS G12C-mutated metastatic colorectal cancer (CRC) after specific chemotherapy has been given.²

Your oncologist will determine if Lumakras is suitable for your situation based on your diagnosis, past treatments, and overall health.

Who Can Take Lumakras (KRAS G12C Testing)

Because Lumakras only works if the cancer has the KRAS G12C mutation, genetic testing of tumour tissue (or sometimes blood) is essential before starting treatment. This ensures the drug targets the right abnormal protein.²

Ask your doctor or care team about diagnostic tests – they can guide whether Lumakras is likely to work for you.

Lumakras Dosage and Schedule

The standard dose of Lumakras for adults is 960 mg taken once daily, at about the same time each day. This is continued until either the cancer progresses, side effects become unacceptable, or your doctor advises stopping.²

Lumakras comes in tablets of different strengths that add up to this daily dose.

How to Take Lumakras

Lumakras can be taken with or without food. Swallow tablets whole unless directed otherwise.²

If you miss a dose and it’s been more than about 6 hours since your usual time, just take the next dose at the regular time the next day. Don’t double up to “catch up.”²

If you vomit after taking a dose, don’t retake it – just take your next dose at the usual time.²

Dose Reductions and Treatment Holds

Some side effects (like liver issues or severe diarrhoea) may prompt your doctor to temporarily stop treatment or reduce the dose. There are established dose reduction levels if needed. If side effects don’t improve, therapy might be discontinued.

Common Side Effects of Lumakras

Side effects vary between people, but the ones reported most often include the following²:

Diarrhoea
Muscle or bone pain
Nausea
Fatigue / tiredness
Cough
Changes in liver blood tests

These are often manageable, but talking to your care team about symptom relief and monitoring is important.

Serious Side Effects and Warnings

Liver toxicity (hepatotoxicity): Lumakras can affect liver function and sometimes cause inflammation or injury. Your doctor will check liver blood tests regularly. Symptoms like yellowing of skin/eyes, dark urine, abdominal pain, or unexplained fatigue should be reported immediately.²

Lung problems [interstitial lung disease (ILD)/pneumonitis]: In rare cases, Lumakras can cause interstitial lung disease – inflammation of lung tissue – which may be serious. New or worsening cough, shortness of breath, or fever needs urgent evaluation.²

Drug Interactions (Acid Reducers and More)

Some medicines can interact with Lumakras. Because of this, it’s important to tell your healthcare provider about all the medicines you take, including prescription medicines, over-the-counter drugs, vitamins, and herbal or dietary supplements.²

In particular, let your doctor know if you take antacid medicines, including proton pump inhibitors (PPIs) or H2 blockers. These medicines may affect how Lumakras works, so your healthcare team may decide how or when they should be taken during treatment.²

Always check with your doctor before starting, stopping, or changing any medications while taking Lumakras.

Monitoring During Treatment

While on Lumakras, your care team will regularly²:

- Check liver blood tests (liver enzymes and bilirubin)

- Ask about symptoms like cough or breathlessness

- Review side effects and adjust treatment as needed

Regular communication with your healthcare team ensures side effects are caught early and managed effectively.

Accessing Lumakras in India Through the Named Patient Program

Lumakras is approved in several countries for the treatment of certain cancers with a KRAS G12C mutation. However, availability may vary across regions in India. In situations where suitable local treatment options are limited, eligible patients may be able to access Lumakras through the Named Patient Program (NPP).³

Under the NPP, a treating oncologist can request Lumakras for an individual patient by submitting:

- Relevant medical records

- Confirmation of the required tumour mutation (KRAS G12C) through biomarker testing

- Clinical justification for treatment

This process may involve regulatory approvals and coordinated import before the medicine is supplied to the treating hospital or cancer centre.

Support services such as Rx4U may assist patients and caregivers with documentation, coordination with healthcare providers, and managing import and delivery logistics. This can help streamline the process and reduce administrative delays.

Final Takeaway

- Lumakras is a targeted therapy for cancers with the KRAS G12C mutation.

- It is commonly used in adults with locally advanced or metastatic NSCLC who have received prior treatment.

- In some cases, it may also be used in KRAS G12C-mutated metastatic CRC in combination with other therapies.

- Biomarker testing for KRAS G12C is required to determine if Lumakras may be suitable.

- In India, access may be possible through the Named Patient Program with physician approval.

Frequently Asked Questions

1. Can Lumakras be used during pregnancy?

Lumakras may cause harm to an unborn baby. Women who are pregnant or planning to become pregnant should inform their doctor before starting treatment.²

2. Can I breastfeed while receiving Lumakras?

Breastfeeding is not recommended during treatment with Lumakras and for a period after the last dose. It is not known whether the medicine passes into breast milk, and it could potentially harm a baby. Speak with your doctor about when it may be safe to resume breastfeeding.²

Medical Disclaimer

This information is provided for educational purposes only and is not a substitute for professional medical advice. Lumakras should only be taken under the guidance of a qualified healthcare provider. Patients should always consult their doctor or pharmacist for advice on diagnosis, treatment, and medication use, and should not make changes to their prescribed therapy without medical supervision.

References:

1. Underwood PW, Ruff SM, Pawlik TM. Update on targeted therapy and immunotherapy for metastatic colorectal cancer. Cells. 2024;13(3):245. doi:10.3390/cells13030245

2. Prescribing information. Amgen Inc.; 2025. Accessed March 4, 2026. https://www.pi.amgen.com/-/media/Project/Amgen/Repository/pi-amgen-com/Lumakras/lumakras_pi_hcp_english.pdf

3. Patil S. Early access programs: benefits, challenges, and key considerations for successful implementation. Perspect Clin Res. 2016;7(1):4-8. doi:10.4103/2229-3485.173779

Note:

Disclaimer:

Rx4U procures prescribed medicines directly from manufacturers or authorized distributors. It does not claim ownership of any trademarks and complies with the provisions of the Trademark Act, 1999, particularly Sections 30 and 30(1) concerning ‘Fair Use’. It solely facilitates access to new launches through named patient import.