Technetium ⁹⁹ᵐTc sulesomab

Technetium ⁹⁹ᵐTc sulesomab is contraindicated in pregnancy.

Radionuclide procedures carried out on pregnant women also involve radiation doses to the foetus. Technetium ⁹⁹ᵐTc sulesomab is contraindicated in pregnancy. Administration of 750 MBq will give an estimated absorbed dose of 4.1 mGy to an embryo or fetus at an early stage.

Before administering a radioactive medicinal product to a mother who is breast feeding, consideration should be given as to whether the investigation could be reasonably delayed until the mother has ceased breast feeding and as to whether the most appropriate choice of radiopharmaceutical has been made, bearing in mind the secretion of activity in breast milk. If the administration is considered necessary, breast feeding should be interrupted and the expressed feeds discarded. It is usual to advise that breast feeding can be restarted when the level in the milk will not result in a radiation dose to the child greater than 1 mSv. Due to the short six-hour, half-life of 99mTc, a dose of less than 1 mSv in mother’s milk can be expected 24 hours after the administration of technetium ⁹⁹ᵐTc sulesomab.

Women of childbearing potential

When it is necessary to administer radioactive medicinal products to women of childbearing potential, information should always be sought about pregnancy. Any woman who has missed a period should be assumed to be pregnant until proven otherwise. Where uncertainty exists, it is important that radiation exposure should be the minimum consistent with achieving the desired clinical information. Alternative techniques which do not involve ionising radiation should be considered.

No studies on the effects on the ability to drive and use machines have been performed.

The following minor, self-limiting, rare adverse events were reported in the clinical trials and considered at least possibly related to technetium ⁹⁹ᵐTc sulesomab: eosinophilia (3); and facial rash (1). None of these were considered serious, and all resolved without sequelae.

Post-marketing experience currently comprises greater than 70,000 vials sold, with two reports of selflimiting allergic reactions.

1. Statistically significant reductions in white blood cell (WBC) count were observed in the controlled studies at 24 hours post-injection, from a mean value of 8.9 to a mean value of 8.0 (× 10³/mm³), but remained within the normal range, and returned to their pre-injection values by the time of the next measurement at 10 days. By contrast, in non-infected subjects, transient increases in WBC count were seen 24 hours after technetium ⁹⁹ᵐTc sulesomab administration. The eosinophil count increased from 2.7% preinjection to 2.9% at 24 hours post-injection, and to 3.9% at 10 days, with the magnitude of both increases being statistically significant. The magnitude of these increases were assessed by the investigators to be of no clinical consequence on an individual patient basis.

It is unknown whether the changes in WBC or eosinophil counts observed, although of no clinical significance, are due to a transient effect on WBC function. If so, no inferences concerning the underlying mechanism(s) responsible may be derived from the clinical laboratory results. However, in vitro granulocyte function tests did not show significant changes when the sulesomab was added.

In vitro, a positive binding to lymphocytes up to 2-6% has been shown. The effect on lymphocyte function has not been determined.

2. HAMA:

No induction of human anti-mouse antibody (HAMA) reactive with fragment was observed in any patient administered technetium ⁹⁹ᵐTc sulesomab.

3. For each patient, exposure to ionising radiation must be justifiable on the basis of likely benefit. The activity administered must be such that the resulting radiation dose is as low as reasonably achievable bearing in mind the need to obtain the intended diagnostic result. Exposure to ionising radiation is linked with cancer induction and a potential for development of hereditary defects. For diagnostic nuclear medicine investigations, the current evidence suggests that the adverse effects will occur with low frequency because of the low radiation doses incurred.

4. For most diagnostic investigations using a nuclear medicine procedure, the radiation dose delivered (effective dose/EDE) is less than 20 mSv. Higher doses may be justified in some clinical circumstances.