Neoadjuvant ipilimumab (3 mg/kg or 10 mg/kg) and high dose IFN-?2b in locally/regionally advanced melanoma: safety, efficacy and impact on T-cell repertoire.

ABSTRACT: BACKGROUND:Neoadjuvant immunotherapy utilizing novel combinations has the potential to transform the standard of care for locally/regionally advanced melanoma. We hypothesized that neoadjuvant ipilimumab in combination with high dose IFN?2b (HDI) is safe and associated with durable pathologic complete responses (pCR). METHODS:Patients with locally/regionally advanced melanoma were randomized to ipilimumab 3 or 10 mg/kg ×?4 doses bracketing definitive surgery, then every 12 weeks ×?4. HDI was given concurrently. We evaluated the safety and efficacy of the combination with ipilimumab 3 or 10 mg/kg. The impact on T-cell fraction and clonality were investigated in tumor and blood. RESULTS:Thirty patients (age 37-76), 15 each at 3 and 10 mg/kg, 18 male and 12 female were treated. Considering immune related adverse events (irAEs) of interest, more grade 3/4 irAEs were seen with ipilimumab 10 mg/kg versus 3 mg/kg (p?=?0.042). Among 28 evaluable patients, 11 relapsed, of whom 5 died. Median follow-up for 17 patients who have not relapsed was 32 months. The radiologic preoperative response rate was 36% (95% CI, 21-54); 4 patients at ipilimumab 3 mg/kg and 6 at 10 mg/kg and 2 (at 10 mg/kg) later relapsed. The pCR was 32% (95% CI, 18-51); 5 patients at ipilimumab 3 mg/kg and 4 at 10 mg/kg and one (at 3 mg/kg) had a late relapse. In patients with pCR, T-cell fraction was significantly higher when measured in primary melanoma tumors (p?=?0.033). Higher tumor T-cell clonality in primary tumor and more so following neoadjuvant therapy was significantly associated with improved relapse free survival. CONCLUSIONS:Neoadjuvant ipilimumab-HDI was relatively safe and exhibited promising tumor response rates with an associated measurable impact on T-cell fraction and clonality. Most pCRs were durable supporting the value of pCR as a primary endpoint in neoadjuvant immunotherapy trials. TRIAL REGISTRATION:ClinicalTrials.gov, NCT01608594 . Registered 31 May 2012.

SUBMITTER: Tarhini A 

PROVIDER: S-EPMC6199801 | biostudies-literature | 2018 Oct

REPOSITORIES: biostudies-literature