Categorieën: Alle - therapy - survival - cancer - chemotherapy

door Eibhlis Myers 1 jaar geleden

325

Lutetium lu 177 vipivotide tetraxetan (pluvicto) Radioligand Therapy for PSMA+ mCRPC

Prostate cancer continues to be a significant health issue for men, ranking as a leading cause of cancer-related death globally. The progression from localized prostate cancer to metastatic castration-resistant prostate cancer (

Lutetium lu 177 vipivotide tetraxetan (pluvicto)                                   Radioligand Therapy for PSMA+ mCRPC

Lutetium lu 177 vipivotide tetraxetan (pluvicto) Radioligand Therapy for PSMA+ mCRPC

Vison Trial

Adverse effects
Renal toxicity

0.9% - ↑ creatinine

3% - Grade 3 or 4 acute kidney injury.

Myleosupression

Fatal events (n=5)

1.1% grade ≥3 pancytopenia occurred (including 2 fatal events)

15% grade 3 /4 ↓ hemoglobin ↓ 9% platelets ↓ 7% leukocytes ↓ 4.5% neutrophils

Results
Secondary end point

Significant increase in Overall Response Rate (ORR)

PSA Decline 46% vs VS 7% 46% of patients who received Pluvicto (BSOC) PSA decline ≥ 50% VS 7%B SOC alone

Primary end point

Median Overall Survival 15.3 months-11. 3 months

Radiographic Free Survival 8.7 months- 3.4 months

Trial Characteristics
Prospective open labelled trial

FDA Approval

Pharmacovigilance
ongoing
Approval in the EU
13 October 2022
USA
2nd of March 2022

Following VISION trial

Manufacturing/ handling

Storage/ Handling
Disposal

Consult the product batch release certificate to identify the source of stable isotopes used- appropriate management for different types of isotopes

In accordance with local radiation safety federal laws.

Storage

Store below 30 do not freeze

Shelf life

120 hours (5 days)

manufacturing
Supply

Struggled to produce/ source enough radioactive material to meet demand

Manufacturing halted last May to sort out supply issues- resumed

2 different stable isotopes: Leutium 177- PSMA 176 + ligand

Complex to make

Pharmacoeconomics

Quality of life
Pluvicto: OS =15.3 months (4 months > then BSOC)
Estimated 38% reduction in risk of death
90% chance of developing bone metastasis (fractures, spinal chord compression)

No therapeutic options remaining

Safety Information

Potential adverse/ adverse drug events
Most Frequent
Potential averse effects/ clinically relevant

Severe renal toxicity

Embryo-fetal toxicity

Life threatening myleosupression

Infertility

Contributes to long-term cumulative radiation exposure.
Minimise close contacts
Minimise effects of radiation by :
Administration precautions

Principles of ALRA (as low as reasonably achievable).

Pharmacokinetics

Clearance
Exposure of drug to kidneys increases with decreasing creatinine clearance.

No dose adjustment rec-ommeded - kidney imparimeny- risk of toxicity

Effects of more severe kidney impairment or end stage kidney disease has not been investigated.

Primaly excreted via the kidneys
Metabolism
Substrates - not a substrate of CYP450 enzymes or of transporters OAT1,OAT3, OCT2.
60-70% bound to human plasma proteins.
Distribution
Within 2.5hr administration - Gastrointestinal tract, liver, lungs, kidneys, heart wall, bone marrow, salivary glands.
Volume of distribution : mean = 123 L
Absorbtion
After Iv admin- mean blood concentration 6.58ng/mL
Whole body and organ radiation dosimetry collected in a subgroup of patients the phase 3 vision trial. n=29

Radiation absorbed doses [mean calculated absorbed dose for 6 x 7.4 GBq (44.4 GBq cumulative activity)

The 6-cycle cumulative estimated absorbed dose in the blood-based red marrow was 1.5 Gy.

Maximum penetration of lutetium-177 in tissue is ≈ 2 mm (mean penetration is 0.67mm)

Organs with highest radiation absorbed: Lacriminal glands, salivary glands , large intestine (left colon, rectum, right colon,kidneys, urinary bladder wall).

Dosage
Supplied: 30 mL single dose vial. Pluvicto solution for injection contains : 7.4 GBq (200 mCi) of radioactivity (at time of use). Slow IV injection (1-10 mins)/ infusion

Administered every 6 weeks for up to 6 treatments.

Administered by a healthcare professional, certified in radio pharmacotherapy.

Blood tests preformed pre and during treatment to monitor PSMA levels.

Do

Pharmacodynamics

Mechanism of Action
Targeted Radioligand therapy

Targeted RLT offers the possibility to treat prostate cancer lesions in a specific and tumour selective manor by exploiting the cell surface proteins mainly expressed on maligant cells.


PSMA-617 (precursor molecule)

Therapeutic radiation can be delivered via PSMA while minimising radiation related side effects. PSMA -targeted RLT uses a radiolabelled small molecule ligand (PSMA617) that binds with high affinity to PSMA, resulting in internalisation and retention within the targeted PC cell.

PSMA-617 complexed with radionucleotide Lu-177

Intra tumoral half life

60/160 hours

Maximal tissue penetration

2mm

Path length of B particles

medium length B emitter

shorter B length- better irradiation for small tumours

direct energy to tumour than surrounding tissue

Physical 1/2 life

6.64 days

+ high intratumoral retention

reduces dosing frequency

Target
PSMA


PSMA is a transmembrane glycoprotein involved in various cellular functions, such as cellular uptake of folate, cell migration, and cell survival.


While PSMA is expressed at low levels in normal prostate epithelium, it is overexpressed (up to 1000 times higher) in 90–95% of prostate cancers. In contrast to benign prostatic epithelium where PSMA resides in the cytoplasm, PSMA is in the luminal epithelium of prostatic ducts in prostate cancers and presents a large extracellular binding domain .


PSMA expression is positively correlated with more aggressive disease, including high PSA, high Gleason scores, and early recurrence. The highest levels of PSMA expression are found in metastatic and castrate-resistant disease


Due to its overexpression on the surface of PC cells, PSMA remains a useful protein target for targeted diagnostic processes and radionuclide therapy in PC



>80% of patients with prostate cancer express PSMA

Therapeutic Indications/ eligibility

Androgen deprivation therapy, in adults previously treated with androgen receptor pathway inhibitors and taxes.

Administered with androgen deprivation therapy

Androgen receptor pathway inhibitors

Taxanes

PET scan performed to check PSMA+ for Pluvicto eligibility

Prostate Cancer

Pathophysiology -mCRPC
Metastatic Prostate Cancer (mPC)

Androgen Depletion Therapy is continued

ADT highly effective- elicits a PSA response

10/20% of patients become castration resistant within 5 years

Castration Resistant Prostate Cancer Therapeutics

>50% die within 3 years with historical standard therapies

NCCN,ESMO,APCCC

None have been proven to prolong survival

No proper sequence for delivery

Tax and based chemotherapy

Chemotherapy side effect profile

Limited options failure of chemotherapy

l

5 year survival = 30%

90% of patients with mCRPC develop bone metastasis

Localised Prostate Cancer

Androgen Depletion Therapy (ADT)

Radiological therapy

Surgical

Epidemiology
2nd leading cause of cancer related death among men in the USA. 3rd leading cause in Europe.
2nd most common cause of cancer in men globally