November 2022: Selpercatinib (Retevmo, Eli Lilly and Company) received accelerated approval from the Food and Drug Administration to treat adult patients with RET-fused solid tumours that are locally or metastatically advanced, have progressed on or after prior systemic therapy, or who have no other effective treatment options.
In LIBRETTO-001 (NCT03157128), a multicenter, open-label, multi-cohort trial evaluating 41 patients with RET fusion-positive tumours (other than non-small cell lung cancer and thyroid cancer) who had disease progression during or after prior systemic treatment or who lacked adequate alternative treatment options, efficacy was shown. Data from 343 patients with RET fusion-positive NSCLC and thyroid cancer who were included in the same trial and previously mentioned in the product labelling provided support for the efficacy evaluation. Patients were given selpercatinib until the disease progressed or the side effects became intolerable.
A Blinded Independent Review Committee chose the overall response rate (ORR) and duration of response (DOR) as the major efficacy measures (BIRC). The ORR among the 41 individuals who could be evaluated was 44% (95% CI: 28, 60), and the DOR was 24.5 months (95% CI: 9.2, not estimable). Pancreatic adenocarcinoma, colorectal, salivary, unknown primary, breast, soft tissue sarcoma, bronchial carcinoid, ovarian, small intestine, and cholangiocarcinoma were among the tumour types that responded.
The patients’ average age was 50. (range 21 to 85). 54% of the population was female, 68% were White, 24% were Asian, 4.9% were Black, 7% were Hispanic/Latino, 95% had an ECOG performance rating of 0 or 1, and 95% had metastatic disease. 37 patients (90%) had previously had systemic therapy (median 2; range 0–9; 32% had previously received 3 or more). Pancreatic (27%), colorectal (24%), salivary (10%), and unknown primary (7%) malignancies were the most prevalent. Using NGS, 97.6% of patients had RET fusion-positive status found, while 2.4% did so using FISH.
Edema, diarrhoea, exhaustion, dry mouth, hypertension, abdominal discomfort, constipation, rash, nausea, and headache were the most frequent side events among patients (25%).
Based on body weight, the suggested dose of selpercatinib is:
120 milligrammes twice daily if you weigh less than 50 kg.
more than 50 kg: 160 mg taken orally twice each day.