A phase I study of the antibody drug conjugate ASG-5ME, an SLC44A4-targeting antibody carrying auristatin E, in metastatic castration-resistant prostate cancer.

Background Antibody drug conjugates (ADC) offer the potential of maximizing efficacy while minimizing systemic toxicity. ASG-5ME, an SLC44A4-targeting antibody carrying monomethyl auristatin E (MMAE), a microtubule-disrupting agent, was investigated in men with metastatic castration resistant prostate cancer. Methods The primary objective of this phase I study was to determine maximum tolerated dose (MTD) and recommended phase II dose. Secondary objectives were safety, antitumor activity, pharmacokinetic properties, immunogenicity, and the detection of SLC44A4 on circulating tumor cells. Patients (pts) were treated among 7 dose levels every 21 days. A dose expansion phase enrolled 20 additional pts. at the MTD. Results Twenty-six and 20 pts. were treated in dose escalation and dose expansion cohorts respectively. The MTD was 2.7 mg/kg. Dose-limiting toxicities occurred in 4 pts.: grade 3 fatigue (n = 1); grade 3 abdominal pain, diarrhea and fatigue (n = 1); grade 4 neutropenia and hyponatremia and grade 3 maculopapular rash, constipation and hypoxia (n = 1); grade 3 troponin elevation without cardiac sequelae (n = 1). Fatigue and diarrhea were the most prevalent adverse events (AEs) across all cycles. Two grade 5 AEs occurred in the dose expansion cohort, each after 1 dose: 1 pt. developed grade 3 hyperglycemia, renal insufficiency and leukopenia; 1 pt. developed grade 3 hyperglycemia complicated by bacteremia. Free MMAE levels did not accumulate with repeat dosing. Of evaluable pts., 52% had either stable disease or a partial response. Conclusions Further development of ASG-5ME is not being pursued due to its narrow therapeutic index. Some toxicities were potentially related to on-target effects on normal tissue expressing the SLC44A4 protein. However, other toxicities were consistent with studies of previous MMAE-containing ADCs. Unconjugated MMAE is a less likely etiology based on prior data.

Hepatoid Adenocarcinoma of the Lung Responsive to Frontline Combination Chemotherapy With Immunotherapy: Case Report.

Hepatoid adenocarcinoma of the lung (HAL) is a rare extrahepatic tumor characterized by histologic features of hepatocellular carcinoma. The standard treatment for nonresectable HAL has not been established, though traditionally, these tumors have been treated with platinum-based chemotherapy. Here, we report the use of combination chemotherapy and immunotherapy in a patient presenting with metastatic HAL and an elevated alpha-fetoprotein. The patient had an excellent clinical, radiographic, and biomarker response. This case supports the use of chemoimmunotherapy, which is now the standard of care first-line treatment in NSCLC, for HAL.

A randomized phase II study of concurrent docetaxel plus vaccine versus vaccine alone in metastatic androgen-independent prostate cancer.

PURPOSE: Docetaxel has activity against androgen-independent prostate cancer and preclinical studies have shown that taxane-based chemotherapy can enhance antitumor response of vaccines. The primary objective of this study was to determine if concurrent docetaxel (with dexamethasone) had any effect on generating an immune response to the vaccine. Secondary end points were whether vaccine could be given safely with docetaxel and the clinical outcome of the treatment regimen. EXPERIMENTAL DESIGN: The vaccination regimen was composed of (a) recombinant vaccinia virus (rV) that expresses the prostate-specific antigen gene (rV-PSA) admixed with (b) rV that expresses the B7.1 costimulatory gene (rV-B7.1), and (c) sequential booster vaccinations with recombinant fowlpox virus (rF-) containing the PSA gene (rF-PSA). Patients received granulocyte macrophage colony-stimulating factor with each vaccination. Twenty-eight patients with metastatic androgen-independent prostate cancer were randomized to receive either vaccine and weekly docetaxel or vaccine alone. Patients on the vaccine alone arm were allowed to cross over to receive docetaxel alone at time of disease progression. The ELISPOT assay was used to monitor immune responses for PSA-specific T cells. RESULTS: The median increase in these T-cell precursors to PSA was 3.33-fold in both arms following 3 months of therapy. In addition, immune responses to other prostate cancer-associated tumor antigens were also detected postvaccination. Eleven patients who progressed on vaccine alone crossed over to receive docetaxel at time of progression. Median progression-free survival on docetaxel was 6.1 months after receiving vaccine compared with 3.7 months with the same regimen in a historical control. CONCLUSION: This is the first clinical trial to show that docetaxel can be administered safely with immunotherapy without inhibiting vaccine specific T-cell responses. Furthermore, patients previously vaccinated with an anticancer vaccine may respond longer to docetaxel compared with a historical control of patients receiving docetaxel alone. Larger prospective clinical studies will be required to validate these findings.

Targeting the androgen receptor in prostate and breast cancer: several new agents in development.

Prostate cancer (PCa) and breast cancer (BCa) share similarities as hormone-sensitive cancers with a wide heterogeneity of both phenotype and biology. The androgen receptor (AR) is a hormone receptor involved in both benign and malignant processes. Targeting androgen synthesis and the AR pathway has been and remains central to PCa therapy. Recently, there has been increased interest in the role of the AR in BCa development and growth, with results indicating AR co-expression with estrogen, progesterone, and human epidermal growth factor receptors, across all intrinsic subtypes of BCa. Targeting the AR axis is an evolving field with novel therapies in development which may ultimately be applicable to both tumor types. In this review, we offer an overview of available agents which target the AR axis in both PCa and BCa and provide insights into the novel drugs in development for targeting this signaling pathway.

A Phase I/II Study for Analytic Validation of 89Zr-J591 ImmunoPET as a Molecular Imaging Agent for Metastatic Prostate Cancer.

PURPOSE: Standard imaging for assessing osseous metastases in advanced prostate cancer remains focused on altered bone metabolism and is inadequate for diagnostic, prognostic, or predictive purposes. We performed a first-in-human phase I/II study of (89)Zr-DFO-huJ591 ((89)Zr-J591) PET/CT immunoscintigraphy to assess performance characteristics for detecting metastases compared with conventional imaging modalities (CIM) and pathology. EXPERIMENTAL DESIGN: Fifty patients with progressive metastatic castration-resistant prostate cancers were injected with 5 mCi of (89)Zr-J591. Whole-body PET/CT scans were obtained, and images were analyzed for tumor visualization. Comparison was made to contemporaneously obtained bone scintigraphy and cross-sectional imaging on a lesion-by-lesion basis and with biopsies of metastatic sites. RESULTS: Median standardized uptake value for (89)Zr-J591-positive bone lesions (n = 491) was 8.9 and for soft-tissue lesions (n = 90), it was 4.8 (P < 0.00003). (89)Zr-J591 detected 491 osseous sites compared with 339 by MDP and 90 soft-tissue lesions compared with 124 by computed tomography (CT). Compared with all CIMs combined, (89)Zr-J591 detected an additional 99 osseous sites. Forty-six lesions (21 bone and 25 soft tissue) were biopsied in 34 patients; 18 of 19 (89)Zr-J591-positive osseous sites and 14 of 16 (89)Zr-J591-positive soft tissue sites were positive for prostate cancer. The overall accuracy of (89)Zr-J591 was 95.2% (20 of 21) for osseous lesions and 60% (15 of 25) for soft-tissue lesions. CONCLUSIONS: (89)Zr-J591 imaging demonstrated superior targeting of bone lesions relative to CIMs. Targeting soft-tissue lesions was less optimal, although (89)Zr-J591 had similar accuracy as individual CIMs. This study will provide benchmark data for comparing performance of proposed prostate-specific membrane antigen (PSMA) targeting agents for prostate cancer.

Acute myeloid leukemia with t(9;11) (p22;q23) and synchronous Langerhans cell histiocytosis.

We present here the first report of an adult patient with simultaneous LCH and AML with t(9;11).5.

Clinical safety of a viral vector based prostate cancer vaccine strategy.

PURPOSE: The primary objective of this phase I study was to evaluate the clinical safety of a vaccine using recombinant vaccinia virus (prime) and recombinant fowlpox virus (boost) in combination with granulocyte-macrophage colony-stimulating factor in patients with prostate cancer. The vaccines contained transgenes for prostate specific antigen, a triad of co-stimulatory molecules and a tumor antigen whose amino acid sequence had been modified to enhance its immunogenicity. Secondary end points were immunological and clinical responses, changes in prostate specific antigen velocity, and the kinetics of vaccinia virus clearance from the vaccination site, serum, peripheral blood mononuclear cells, urine and saliva. MATERIALS AND METHODS: The 15 patients enrolled in this study had metastatic prostate cancer. Patients were given recombinant fowlpox-prostate specific antigen/triad of co-stimulatory molecules alone or recombinant vaccinia-prostate specific antigen/triad of co-stimulatory molecules followed by recombinant fowlpox-prostate specific antigen/triad of co-stimulatory molecules on a prime and boost schedule with or without recombinant-granulocyte-macrophage colony-stimulating factor protein or recombinant fowlpox-granulocyte-macrophage colony-stimulating factor vector. Prostate specific antigen specific immune responses were measured using an enzyme-linked immunosorbent spot assay for interferon-gamma production. Polymerase chain reaction for vaccinia DNA and a plaque assay for live virus were also used. RESULTS: Some grade 2 toxicity was seen in patients who received a higher dose of recombinant fowlpox-granulocyte-macrophage colony-stimulating factor but no toxicity exceeded grade 2. Viable vaccinia was detected after vaccination at the site swab of 1 of 4 patients analyzed. Prostate specific antigen specific immune responses were seen in 4 of 6 patients who were HLA-A2+ and decreases in serum prostate specific antigen velocity were observed in 9 of 15. CONCLUSIONS: Based on the safety and preliminary immunogenicity results of this trial we recommend initiating a randomized, phase II study of prostate specific antigen/triad of co-stimulatory molecules vaccines in patients with less advanced prostate cancer.