CytomX studies CX-072 plus Yervoy in melanoma patients

CytomX Therapeutics has launched a Phase II clinical trial of its drug candidate CX-072 in combination with Yervoy (ipilimumab) for the treatment of relapsed or refractory melanoma.

CX-072 is an anti-PD-L1 Probody, while Yervoy is Bristol Myers Squibb’s anti-CTLA-4 antibody.

The Phase II PROCLAIM-CX-072-00 study will assess the combination in unresectable or metastatic melanoma patients who progressed or relapsed after a PD-1/PD-L1 immune checkpoint inhibitor therapy.

During the open-label, multi-centre trial, the efficacy and tolerability of 800mg CX-072 every three weeks will be tracked when given in combination with ipilimumab at 3mg/kg every three weeks for four cycles.

Following the completion of the combination phase, treatment with CX-072 will be continued once every two weeks until disease progression.

The trial’s primary objective is the overall response rate (ORR), while secondary objectives are CX-072’s safety and tolerability. Initial results from the study are expected to be reported next year.

CytomX Therapeutics chief development officer Amy Peterson said: “Patients whose melanoma has progressed despite prior treatment with checkpoint inhibition remain a significant unmet medical need.

“This exciting study leverages our unique technology platform to enable a more powerful combination therapy directed against the two best validated pathways in immuno-oncology and could represent a significant advance in outcomes for these patients who have few treatment options.”

The company has also reported new results from the Phase I PROCLAIM-CX-072-001 trial of the combination in patients suffering from advanced solid tumours.

According to the results, 27 evaluable patients treated with the combination had a disease control rate of 37%. In addition, five patients experienced confirmed objective responses, including one complete response, with a 19% ORR in heavily pretreated patients.

The median duration of response was 14.6 months. The CX-072 and Yervoy combination was generally well-tolerated without any new safety signals.