TLD-1, a novel liposomal doxorubicin, in patients (pts) with advanced solid tumors: Dose escalation and expansion part of a multicenter open-label phase I trial (SAKK 65/16)

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Background: TLD-1 is a novel liposomal doxorubicin that compared favorably to conventional liposomal formulations of doxorubicin in preclinical in vivo mouse breast cancer models. This phase I first-in-human trial is aiming to determine the recommended phase II dose (RP2D), toxicity profile, pharmacokinetics and preliminary activity. Methods: Patients with a maximum of 3 prior lines of systemic chemotherapy and preferably anthracycline-sensitive disease were eligible. TLD-1 was administered on day 1 iv over 60-90 minutes (depending on individual dose) q 21 days, for up to 6 or 9 cycles (according to prior anthracycline-exposure) with premedication of 8mg dexamethasone. Dose escalation with dose levels (DL) 1-7 of 10, 16, 23, 30, 35, 40 and 45mg/m2 started with an accelerated titration design, treating one pt at each DL up to DL6 (40mg/m2) followed by a modified continual reassessment method at DL7 due to observed toxicity. Results: 30 pts (F:M = 24:6) have been treated, one each at DLs 1-6, 15 pts at DL7 and an additional 9 pts at DL6. Most frequent tumor types included breast (n = 13), ovarian (n = 6), cervical cancer (n = 2) and cholangiocarcinoma (n = 2). Median age was 67.5 years (range:38-83), 13 pts were exposed to prior anthracyclines. The median number of cycles was 4 (range:1-9). No dose-limiting toxicities (DLT) occurred during cycle 1. At DLs 1 to 5, no treatment-related G3 AEs (TRAE) were observed. At DL6, there was one case of mucositis G3, one of palmar-plantar-erythrodysesthesia (PPE) G3 and one of anemia and neutropenia G3 each. One patient with pre-existing valvular cardiopathy developed symptoms of heart-failure G3 after 8 cycles. Echocardiography showed severe mitral regurgitation with normal LV-EF. In addition one case of urinary-tract infection G3 was seen. Dose-modifications or -delays due to AEs occurred in 7/50 cycles. At DL7, one case of mucositis G3, 3 events of PPE G3 and one case of fatigue G3 were reported. In addition, one case of infection with shingles occurred. Dose-modifications or -delays due to AEs occurred in 12/61 cycles. Shingles and heart failure were reported as SAEs. All toxicities listed above were categorized as TRAE. 29/30 pts were evaluable for response. Three breast cancer pts had a partial response, 2 at DL7 and 1 at DL6, 14 pts had stable disease. Conclusions: No DLT was observed up to DL7. RP2D was defined at 40mg/m2 due to cumulative PPE G3 at DL7. The trial is ongoing with a comparative PK-part evaluating the two iv liposomal formulations of doxorubicin TLD-1 and Caelyx. Clinical trial information: NCT03387917.

Intestinal inflammation alters mucosal carbohydrate foraging and monosaccharide incorporation into microbial glycans

Endogenous carbohydrates released from the intestinal mucus represent a constant source of nutrients to the intestinal microbiota. Mucus-derived carbohydrates can also be used as building blocks in the biosynthesis of bacterial cell wall components, thereby influencing host mucosal immunity. To assess the uptake of endogenous carbohydrates by gut microbes in healthy mice and during intestinal inflammation, we applied azido-monosaccharides that can be tracked on bacterial cell walls after conjugation with fluorophores. In interleukin-10 deficient mice, changes in the gut microbiota were accompanied by decreased carbohydrate hydrolase activities and increased lumenal concentrations of host glycan-derived monosaccharides. Tracking of the monosaccharide N-azidoacetylglucosamine (GlcNAz) in caecum bacteria revealed a preferential incorporation of this carbohydrate by Xanthomonadaceae in healthy mice and by Bacteroidaceae in interleukin-10 deficient mice. These GlcNAz-positive Bacteroidaceae fractions mainly belonged to the species B. acidifaciens and B. vulgatus. Growth of Bacteroides species in the presence of specific monosaccharides changed their stimulatory activity toward CD11c⁺ dendritic cells. Expression of activation markers and cytokine production was highest after stimulation of dendritic cells with B. vulgatus. The variable incorporation of monosaccharides by related Bacteroides species underline the necessity to investigate intestinal bacteria down to the species level when addressing microbiota-host interactions.