Poor penetration of anti-cancer drugs into tumors can be an important factor limiting their efficacy. Studying mouse tumor models, we show that a previously characterized tumor-penetrating peptide, iRGD (CRGDK/RGPD/EC), increased vascular and tissue permeability in a tumor-specific and neuropilin-1-dependent manner, allowing co-administered drugs to penetrate into extravascular tumor tissue. Importantly, this effect did not require the drugs to be chemically conjugated to the peptide. Systemic injection with iRGD improved the therapeutic index of drugs of various compositions including a small molecule (doxorubicin), nanoparticles (nab-paclitaxel and doxorubicin liposomes), and a monoclonal antibody (trastuzumab). Thus, co-administration of iRGD may be a valuable way to enhance the efficacy of anti-cancer drugs while reducing their side effects, a primary goal of cancer therapy research.

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and 9 Gilead Sciences Inc., Foster City, CA Key Points• Concomitant PI3Kd and SYK inhibition resulted in treatment-emergent pneumonitis, necessitating early study termination.• Initial trials of novel combinations should use conservative designs that are focused on safety.Although agents targeting B-cell receptor signaling have provided practice-changing results in relapsed chronic lymphocytic leukemia (CLL) and non-Hodgkin lymphoma (NHL), they require prolonged administration and provide incomplete responses. Given synergistic preclinical activity with phosphatidylinositol 3-kinase d and spleen tyrosine kinase inhibition, this phase 2 study evaluated the safety and efficacy of the combination of idelalisib and entospletinib. Eligible patients with relapsed or refractory CLL or NHL underwent intrapatient dose escalation with each agent. With a median treatment exposure of 10 weeks, 60% and 36% of patients with CLL or follicular lymphoma, respectively, achieved objective responses. However, the study was terminated early because of treatmentemergent pneumonitis in 18% of patients (severe in 11 of 12 cases). Although most patients recovered with supportive measures and systemic steroids, 2 fatalities occurred and were attributed to treatment-emergent pneumonitis. Increases of interferon-g and interleukins 6, 7, and 8 occurred over time in patients who developed pneumonitis. Future studies of novel combinations should employ conservative designs that incorporate pharmacodynamics/biomarker monitoring. These investigations should also prospectively evaluate plasma cytokine/chemokine levels in an attempt to validate biomarkers predictive of response and toxicity.

SummaryIbrutinib is effective in patients with chronic lymphocytic leukaemia (CLL); however, treatment resistance remains a problem. Ublituximab is a novel, glycoengineered anti‐CD20 monoclonal antibody with single‐agent activity in relapsed CLL. We report the results of a phase 2 study evaluating combination therapy with ibrutinib and ublituximab in patients with relapsed or refractory CLL. Patients received ibrutinib 420 mg once daily. Ublituximab was administered on days 1, 8 and 15 of cycle 1 followed by day 1 of cycles 2–6. Response assessments were completed at cycles 3 and 6; patients then continued on ibrutinib monotherapy per standard of care. Forty‐one of 45 enrolled patients were evaluable for efficacy. Safety was consistent with prior experience for each drug, with infusion reactions the most prevalent adverse event. Combination therapy resulted in an overall response rate (ORR) of 88% at 6 months. In the 20 patients with high‐risk features (17p or 11q deletions or TP53 mutation) and evaluable for efficacy, the ORR was 95%, with three patients (15%) achieving negative minimal residual disease. Median time to response was 8 weeks. Ublituximab in combination with ibrutinib resulted in rapid and high response rates. The long‐term clinical benefit of ublituximab will be defined by an ongoing phase 3 trial (NCT 02301156).