Eligible patients must have metastatic renal cell carcinoma, mantle cell lymphoma, or diffuse large B-cell lymphoma (including Grade 3b follicular lymphoma) with CD70+ confirmed relapsed/refractory disease after &ge;2 prior therapies, ECOG 0-1, adequate organ function, and measurable disease. Exclusions include prior anti-CD70 therapy (unless CD70+ confirmed post-treatment), recent allogeneic stem cell transplant (<100 days), or recent anticancer treatment (<4 weeks, or <2 weeks if progression occurred).

The best clinical response observed at all dose levels is displayed in Table 4. One patient in the 50-ug/kg cohort achieved a partial response (PR) (6%), with a time to first response of 18.4 weeks and a response duration of ≥7.3 weeks (Fig. 1). Most patients (13 of 18; 72%) had SD, yielding an overall disease control rate of 78% (95% confidence interval, 52.4%-93.6%). Tumor size post-treatment is illustrated in Figure 2. It is noteworthy that 2 patients (1 with PR and 1 with SD) in the 50-ug/kg cohort had ongoing tumor reductions more than 6 weeks after the end of treatment (each patient had received 2 doses). Both patients experienced grade 2 thrombocytopenia, which was persistent in 1 patient. The estimated median PFS was 3.5 months (95% confidence interval, 2.1-6.3 months) (Fig. 3). Four patients are known to have died, and 14 were still alive at the last follow-up, including the patient who had a PR. The follow-up for those who remained alive at the last follow-up ranged from ≥1.4 to ≥9.7 months. Two patients who died were known to have survived for 17.6 and 14.1 months with a best response of SD. Prior immunotherapy with programmed death 1 (PD-1)/PD-L1 inhibitors was received by 4 patients (22.2%); however, the patient who attained a PR was not among them.