A phase I/II dose-escalation study of fractionated 225Ac-J591 for progressive metastatic castration-resistant prostate cancer (mCRPC) in patients with prior treatment with 177Lu-PSMA

TPS288

Background: As prostate-specific membrane antigen targeted radiotherapy (PSMA-TRT) is now an active standard-of-care treatment in mCRPC, ongoing studies with alternative approaches to targeting PSMA will increasingly need to consider the consequences of sequential PSMA-TRT exposure. Our past and ongoing investigations into antibody-based targeting (e.g., J591) and potent alpha emitting payloads (e.g., 225Ac) impact drug kinetics, biodistribution, and resultant clinical toxicities. In a first-in-human phase I dose-escalation study of 225Ac-J591, patients with mCRPC were treated with a single dose of 225Ac-J591 on seven dose levels, up to 93.3 KBq/kg without achievement of maximal tolerated dose (MTD). One patient treated at 80 KBq/kg developed dose-limiting toxicity (DLT) of Gr 4 anemia and thrombocytopenia, but 0 of 6 at 93.3 KBq/Kg had Gr > 3 heme toxicity or Gr > 2 non-heme toxicity. Although not intentionally preselected for prior exposure, 55% (12/22) of patients had 177Lu-PSMA previously. With approval of 177Lu vipivotide tetraxetan, we amended an ongoing phase I dose-escalation study to include a post-177-Lu-PSMA cohort. Methods: Entry criteria include progressive mCRPC by PCWG3 criteria, ECOG PS 0-2, intact organ function, and prior receipt of AR pathway inhibitor and chemotherapy (or refused/ineligible). There is no limit to prior lines of therapy except alpha-emitting therapies (i.e., PSMA-TRT, 223Ra) and in this amended dose-escalation cohort, all patients must have had prior treatment with 177Lu-PSMA. Treatment will be given in a single fractionated cycle of 225Ac-J591 administered on D1 and D15. The phase I component is a 3+3 dose-escalation study design with up to 18 patients, with the goal of identifying MTD. The phase II component will include up to 16-19 patients in a Simon 2-stage design with 90% power to exclude the null hypothesis (35% or fewer patients with PSA50). Eligible men with negative PSMA PET scans will be offered treatment with informed consent in an exploratory subgroup but will not be counted towards phase II efficacy. Secondary outcomes include radiographic response by PCWG3-modified RECIST 1.1 criteria and PSMA PET, biochemical and radiographic progression-free survival, circulating tumor cell counts, and overall survival. Patient reported outcomes, genomic, and immune analyses are exploratory. Enrollment to the post-177Lu-PSMA cohort began in August 2022. Clinical trial information: NCT04506567 .

Phase I/II study of 225Ac-J591 plus 177Lu-PSMA-I&T for progressive metastatic castration-resistant prostate cancer

TPS5100

Background: PSMA is overexpressed by most prostate cancers and can be successfully targeted by both antibodies (mAb) and small molecule ligands (SML), each with overlapping and distinct binding sites, kinetics, and biodistributions [Kratochwil Sem Nuc Med 2019]. mAbs are larger, with longer circulating times resulting in greater exposure to bone marrow, but lesser access to PSMA expression on luminal tissue ( e.g. salivary glands, small bowel, and kidney). In contrast, SMLs are rapidly excreted via kidneys and readily diffuse to all PSMA-expressing sites. Toxicities of 177Lu vary with these differences in biodistribution ( e.g. more hematologic toxicity with mAb, more xerostomia and nausea with SML, p < 0.001)[Niaz AUA 2020]. Alpha emitting isotopes have shorter ranges but high potency compared to beta emitters which have longer ranges, but lower linear energy transfer. In preclinical models, the combination of mAb plus SML has demonstrated additive binding in LNCaP, CWR22Rv1, and PC3/PSMA PC cell lines, and synergistic uptake of 177Lu-mAb plus 177Lu-SML in xenograft models. We developed a phase I/II study to test our hypothesis that concomitant mAb and SML targeting, plus the combination of alpha (225Ac) and beta emitters (177Lu), may offer complementary benefits in a safe and effective manner. Methods: Key eligibility criteria include progressive mCRPC (PCWG3), at least 1 prior AR pathway inhibitor and taxane chemotherapy (or ineligible/refused), and adequate organ function and performance status. PSMA PET/CT must have at least 1 lesion with SUVmax > liver SUV. Prior PSMA-based therapy with radioisotopes is not allowed. 177Lu-PSMA-I&T (PNT2002) will be administered as in the phase III SPLASH study (6.8 GBq q8w for up to 2 doses). The phase I includes up to two dose-escalation cohorts of concurrent 225Ac-J591 (30 & 40 KBq/Kg q8w x2) in a modified 3+3 schema. All subjects undergo 177Lu SPECT on Day 8 after each dose. The primary objective of the Phase I study is to determine the dose-limiting toxicity and recommended phase II dose (RP2D) for this combination. Primary objective of the Phase II study is to assess the proportion of patients with > 50% PSA decline after treatment. Secondary objectives include radiographic response rate (PCWG3-modified RECIST 1.1), biochemical and radiographic progression-free survival, overall survival, safety (CTCAE 5.0), CTC count changes and conversions, and patient-reported outcomes (FACT-P, BPI-SF, EQ-5D). Exploratory objectives include pre- and post-treatment PSMA-based imaging changes, effects of PSMA radionuclides on the microbiome, relationship between genomic alterations and response, and relationship between PSMA PET/CT results and outcome. The phase I was activated at Weill Cornell Medicine in May 2021. Following determination of the RP2D, a multicenter phase II is planned at Prostate Cancer Clinical Trials Consortium (PCCTC) in 2022. Clinical trial information: 04886986.

Totally extraperitoneal inguinal hernioplasty with titanium-coated lightweight polypropylene mesh: early results

BACKGROUND

This prospective study of a new titanium-coated low-weight polypropylene (PP) mesh (16 g PP/m2) was designed to investigate the clinical efficacy and safety of totally extraperitoneal endoscopic hernioplasty (TEP).

METHODS

In this study, 400 patients (average age, 53.5 years; range, 19-80 years) with a total of 588 inguinal hernias underwent surgery with the TEP technique between September 2002 and October 2003. Of these patients, 12.4% had experienced recurrent hernias after open suture herniotomy. In 92% of the cases (368 patients with 540 hernias), a lightweight (16 g PP/m2) titanium-coated polypropylene mesh was implanted without fixation, and in 8% (32 patients with 48 hernias) an identical medium-weight (35 g PP/m2) mesh was implanted. The first follow-up examination was scheduled for postoperative week 6.

RESULTS

In the lightweight mesh group, the mean group, operating time per patient was 61 min, corresponding to a calculated time per hernia of 41 min. Two intraoperative major complications occurred: an injury to the cecum and an injury to the bladder. In 12 cases (2%), bleeding from epigastric, testicular, or pubic bone vessels was observed. No injuries to pelvic vessels were seen. One patient was underwent an endoscopic revision to deal with an anticoagulation-related bleed. The mortality rate was 0%. In 12 patients, postoperative hematomas developed. One preperitoneal lipoma had to be extirpated. No infections of the mesh occurred. The median follow-up period for 371 patients (92.3%) was 7.2 weeks (range, 4-14 weeks). These 343 patients (with 504 hernias) had been provided with a lightweight titanium-coated polypropylene mesh (16 g PP/m2) (follow-up rate, 93.2%). Of these patients, 3.5% reported persistent ingunial pain, 1.7% described a sensation of rigidity in the region of the groin, and 3.2% reported dysesthesia. The early recurrence rate was 0.2%.

CONCLUSIONS

The TEP procedure can be performed safely and effectively with the appreciably material-reduced and titanium-coated polypropylene mesh without the need for fixation of the implant. The low early recurrence rate of 0.2% is evidence that the posterior wall of the inguinal canal is adequately augmented. The question whether the material reduction and the titanium coating of the mesh may bring about a reduction in postoperative chronic pain and the sensation of rigidity in the inguinal area via an improvement in biocompatibility must await the results of the scheduled follow-up examination 1 year after the surgical procedure.

Safety and toxicity of amphotericin B in glucose 5% or intralipid 20% in neutropenic patients with pneumonia or fever of unknown origin: randomised study

OBJECTIVE

To compare the feasibility of treatment, safety, and toxicity of intravenous amphotericin B deoxycholate prepared in either glucose or intralipid for empirical antimycotic treatment of neutropenic cancer patients.

DESIGN

Single centre stratified, randomised non-blinded phase II study.

SETTING

University hospital providing tertiary clinical care.

SUBJECTS

51 neutropenic patients (leukaemia (35), lymphoma (11), solid tumours (5)) with refractory fever of unknown origin (24) or pneumonia (27).

INTERVENTIONS

Amphotericin B 0.75 mg/kg/day in 250 ml glucose 5% solution or mixed with 250 ml intralipid 20%, given on eight consecutive days then alternate days, as a 1-4 hour infusion.

MAIN OUTCOME MEASURES

Feasibility of treatment, subjective tolerance (questionnaire), and objective toxicity (common toxicity criteria of the National Cancer Institute).

RESULTS

Study arms were balanced for age, sex, underlying malignancy, renal and liver function, and pre- and concomitant treatment with antibiotics and nephrotoxic agents. No statistically significant or clinically relevant differences were found between the treatment groups for: daily or cumulative dose and duration of treatment with amphotericin B; incidence and time of dose modifications or infusion duration changes related to toxicity; dose or duration of symptomatic support with opiates, antipyretics, or antihistamines; renal function; subjective tolerance; most common toxicity scores; course of infection; and incidence of treatment failures. Patients treated with amphotericin B in intralipid were given fewer diuretics (P<0.05) and therefore had more peripheral oedema (P<0.01) and needed less potassium supplementation (P<0.05) than patients given amphotericin in glucose. Acute respiratory events were more common in the intralipid arm (P<0.05).

CONCLUSIONS

Amphotericin B 0.75 mg/kg/day in intralipid given on eight consecutive days then alternate days provides no benefit and is associated with potential pulmonary side effects possibly because of fat overload or an incompatibility of the two drugs.