Five RCTs (n=477) were included in the review. Two RCTS looked at Sm-153-lexidronam, while 3 looked at Sr-89.
Effectiveness.
Both Sm-153-lexidronam and Sr-89 were more effective than placebo in relieving bone pain due to skeletal metastases from carcinoma of the prostate. One of the 2 RCTs found a decreased use of analgesics following Sm-153-lexidronam. The pooled results were as follows.
Sm-153-lexidronam versus placebo (n=2): the OR for pain relief was 2.52 (95% confidence interval, CI: 1.42, 4.46).
Sr-89 versus placebo (n=3): the OR for pain relief was 2.49 (95% CI: 0.46, 13.47).
Safety.
The total incidence of Sm-153-lexidronam-related anaemia, thrombocytopenia and leucocytopenia was significantly higher than that in the placebo group. Severe toxicity with clinical significance was seen in only 5 and 8% of patients treated with Sm-153-lexidronam for Grade 3 platelet toxicity and Grade 3 white blood cell toxicity, respectively. Both RCTs employed a single administration of Sm-153-lexidronam, so it is uncertain whether it is safe when given repeatedly.
Sr-89 treatment significantly increased at least Grade 2 platelet toxicity, the incidence of haemorrhage, and Grades 1 to 3 white blood cell toxicity. The severity of the observed myelosuppression may be related to the high dose-intensity of the Sr-89 used in early studies.