What is Lu PSMA (Lutetium-Prostate Specific Membrane Antigen) Therapy?

Lu177 PSMA Therapy is a treatment for patients with prostate cancer, especially those who have become refractory to conventional therapy. Lutetium PSMA therapy helps to slow down the growth of the cancer cells, reduce the size of the tumours and most importantly improve the quality of life of the patients by reducing the pain caused by the cancer.

Many prostate cancers, in particular those that have spread or become resistant to hormonal therapies, express a unique receptor on their cell surface called Prostate Specific Membrane Antigen (PSMA). When Prostate Cancer metastasizes i.e. spreads to other parts of the body, the PSMA receptor is expressed over the sites of metastases as well.

How does Lu PSMA Therapy Work?

Lutetium-177 is a radioactive substance that emits beta radiation, a destructive kind of radiation. Lutetium-177 is bound to a small peptide which attaches to the PSMA receptor expressed on the cancer cell surface. The Lutetium 177 – PSMA complex, thus attached to the prostate cancer cell, then emits killing radiation causing cell death of the cancer cell. Since the penetration of the emitted beta particle is very small, the surrounding normal cells are spared.

How is the Therapy Done?

Lu177 PSMA is administered intravenously. The patient is admitted to the hospital for 24 hours. A kidney function scan called a MAG3/EC scan is done prior to the administration of the Lu177 PSMA.

What are the Side Effects of Lu PSMA Therapy?

Lu177 PSMA is well tolerated. The most common side effects are a slightly dry mouth, fatigue and nausea. There may also be a slight fall in the white blood cells and platelets about 2 – 3 weeks after the Lu177 PSMA administration.

What is the Response Rate With Lu PSMA Therapy?

The response rates of Lu177 PSMA depend on the tumour biology of prostate cancer, the initial Gleason Score, the extent of disease and the responses to prior therapies. Typically, more than 70% of patients demonstrate a reduction in S. PSA and a shrinkage of tumours following Lu177 PSMA therapy.

When would the doctor consider using this Therapy?

Lu PSMA Therapy is a very specific therapy and is used for managing metastatic Prostate Cancer or when Prostate Cancer is no longer responsive to other types of treatment.

What are the Treatment Schedules with Lu PSMA Therapy?

Most patients undergo three-four treatment cycles at intervals of 8-12 weeks. The number of cycles and the interim duration may vary between individuals depending on the response and interim assessments.

Why should I choose the nuclear medicine therapy center at Fortis Memorial & Research Institute (FMRI), Gurugram (Haryana, India)?

The Nuclear Medicine Therapy Centre at FMRI was one of the first institutes to offer Radio-ligand Therapy with Lu PSMA, and today, the center receives patients from the country and from across the world.

Everything you need to know about Alpha PSMA Therapy

Summary (10 sec read)

Prostate cancer is a prevalent malignancy, especially in men over 60, and is a significant cause of cancer-related mortality. Advanced prostate cancer often requires targeted treatment to control its spread. Alpha PSMA Therapy, using the alpha-emitting radioisotope Actinium-225 (225Ac), offers a promising solution for metastatic castration-resistant prostate cancer (mCRPCa). This therapy targets PSMA, an antigen overexpressed in prostate cancer cells, delivering targeted radiation that minimizes harm to healthy tissues.

Fortis Memorial Research Institute (FMRI) in India is one of the leading centres for this therapy in Asia, completing 500 treatment cycles with remarkable results. Patients have experienced improved quality of life, reduced symptoms, and significant drops in serum PSA levels, reflecting a decreased tumor burden. While dry mouth is a common side effect, severe issues like bone marrow suppression are rare. Ga68 PSMA scans indicate up to 70% tumor reduction after a single cycle for some patients. FMRI ensures high-quality treatment by sourcing 225Ac from ITG Germany and purified peptides from ABX Germany, performing in-house labeling.

According to the World Cancer Research Fund, Prostate Cancer is not only one of the most common malignancy in men but also one of the most commonly occurring cancer overall. Prostate Cancer is also the fifth leading cause of death from cancer in men. Disease progression and metastatic spread signifies the beginning of a lethal form of the disease – metastatic castration resistant prostate cancer (mCRPCa).

The incidence of prostate cancer increases proportionally with age, especially in men above 60 years of age. Studies have also shown that incidence of prostate cancer also depend on demographics and racial prevalence – prostate cancer has a low incidence in Asia (3-8 per 100,000 men per year), an intermediate incidence in Africa and Eastern Europe, and a higher incidence in North America and Western Europe.

While conventional treatment modalities for localized prostate cancers include surgery, chemotherapy, cryotherapy, brachytherapy with radioactive seeds, and usage of external radiation, advanced prostate cancer and metastasized prostate cancer treatment focuses on controlling the spread of the cancer. And in order to optimize the therapeutic outcome, especially in high-risk prostate cancer patients, the treatment is increasingly moving toward personalization. This is where Nuclear Medicine and Molecular Imaging play an important part in the management of cancer in a personalized manner. The objective of the treatment here is to deliver patient-specific, targeted treatment at the most appropriate time. And with advances in the radiopharmaceuticals chemistry and imaging technologies, the role of nuclear medicine and molecular imaging for both diagnosis and therapy, of prostate cancer will increase significantly in the near future.

The past few years have been witness to tremendous progress towards the identification of appropriate molecular targets that could enable efficient therapy of metastatic castration resistant prostate cancer (mCRPCa). An enzymatic target that is proving its efficacy is an antigen that is overexpressed on prostate cancer cells – PSMA (Prostate-Specific Membrane Antigen).

Several nuclear medicine clinics around the world have confirmed that Targeted Alpha Therapy (TAT) or Alpha PSMA Therapy using radiolabeled PSMA inhibitors, has the potential to bring about a paradigm shift in the treatment of metastatic castration resistant prostate cancer (mCRPCa) patients. Based on preclinical and clinical data reported, doctors are confident that this therapeutic modality will play a much bigger role in the management of advanced stage prostate cancer in the coming years.

So, the question that most patients and caregivers ask – What is Targeted Alpha Therapy or Alpha PSMA Therapy? In simple terms, Targeted Alpha Therapy/ Alpha PSMA Therapy is a targeted, selective internal medicine cellular level radiotherapy used to control advanced prostate and prostate cancer.

Also Read: How Nuclear Medicine Is Transforming The Fight Against Cancer

Alpha PSMA Therapy uses alpha-emitting radioisotopes like ²²⁵AC and is a completely safe and effective therapy with very minimal side-effects. The department of Nuclear Medicine and Molecular Imaging at the Fortis Memorial & Research Institute (FMRI) was the pioneer of this therapy not only in India but also in Asia. The centre is currently the only centre that offers this therapy in India on a regular basis.

As far as side-effects of this therapy are concerned, the most common side-effect is Xerostomia or dry mouth. While this seems to distress some patients, most of the patients do not report a very significant impact on their lifestyle because of xerostomia. More importantly, most patients show no signs of bone marrow suppression or damage to the kidney or liver due to targeted Alpha PSMA Therapy.

The Department of Nuclear Medicine and Molecular Imaging at Fortis Memorial Research Institute (FMRI) has till date completed 50 treatment cycles at the centre and the team is extremely excited with the initial results. With each therapy cycle, most of the patients who have undergone the treatment have experienced a remarkable improvement in their quality of life as a result of reduced symptoms and pain. Furthermore, there has also been an associated biochemical response with a fall in serum PSA levels - this is an indication of a reduced tumor burden in the body. In fact, most patients have also shown a prolonged duration of response with some patients being in near-complete biochemical and clinical remission for over a year. These patients continue in clinical remission and as time goes by, the impact of ²²⁵AC PSMA Therapy or Alpha PSMA Therapy on the overall survival would become clearer.

Further, in order to get a better understanding of the efficacy of Alpha PSMA therapy, the team at the centre has performed Ga68 PSMA scans before the next due cycles and have witnessed some encouraging results – nearly 70% of reduction in tumor in a single cycle in some patients.

One of the key factors that ensures the efficacy of Targeted Alpha PSMA Therapy in the treatment of metastatic castration resistant prostate cancer (mCRPCa) is the quality of radioisotope used (i.e. the quality of ²²⁵AC). The centre at Fortis Memorial sources the ²²⁵AC from Mssrs ITG Germany, and it has the approval from the European Medicines Association as well as the Indian Pharmacopia. The highly purified peptides are sourced from ABX Germany. The labelling of ²²⁵AC with the peptide is done in-house. The centre assures that the highest standards of quality are maintained at every level.

For further information and/ or consultation, Visit Nuclear Medicine Therapy, do call at +91 98111 27080 or write to us at info@nuclearmedicinetherapy.in

Also Read: An In-Depth look at Prostate Cancer