A phase I trial of the HIV protease inhibitor nelfinavir in adults with solid tumors

Nelfinavir is an HIV protease inhibitor being repurposed as an anti-cancer agent in preclinical models and in small oncology trials, yet the MTD of nelfinavir has not been determined. Therefore, we conducted a Phase Ia study to establish the maximum tolerated dose (MTD) and dose limiting toxicities (DLT) of nelfinavir in subjects with advanced solid tumors. Adults with refractory cancers were given oral nelfinavir twice daily with pharmacokinetic and pharmacodynamic analyses. Twenty-eight subjects were enrolled. Nelfinavir was generally well tolerated. Common adverse events included diarrhea, anemia, and lymphopenia, which were mostly mild. The DLT was rapid-onset neutropenia that was reversible. The MTD was established at 3125 mg twice daily. In an expansion cohort at the MTD, one of 11 (9%) evaluable subjects had a confirmed partial response. This, plus two minor responses, occurred in subjects with neuroendocrine tumors of the midgut or pancreatic origin. Thirty-six percent of subjects had stable disease for more than 6 months. In peripheral blood mononuclear cells, Nelfinavir inhibited AKT and induced markers of ER stress. In summary, nelfinavir is well tolerated in cancer patients at doses 2.5 times the FDA-approved dose for HIV management and showed preliminary activity in tumors of neuroendocrine origin.

A pilot study of sirolimus (S) in subjects with Cowden syndrome (CS) with germ-line mutations in PTEN

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Background: CS is characterized by germline PTEN mutations. Because tumors from CS patients show increased activation of the PI3K/Akt/mTOR pathway, mTOR inhibitor such as S might have activity in such patients. Methods: Eligibility: subjects with germline PTEN mutation who meet international diagnostic criteria for CS, age 18, ECOG PS 0-2, and adequate organ function. Subjects were treated with a 56-day course of daily oral S (2 mg). Objective: Inhibition of the mTOR pathway in benign skin/GI lesion, as assessed by IHC (P-AKT, Total S6, P-S6, P-4E-BP1, score 0-4), changes in benign or malignant tumor by CT/MRI/PET, digital dermoscopy/endoscopy, and changes in cerebellar testing by modified SARA (Neurology 2006). Protocol was amended to allow up to 20 subjects. Results: A total of 18 pts/16 families were enrolled. Median age 42 (range 19-69). Male/Female: 9/9. Involvement in skin, thyroid, GI polyps, breast, CNS, and all of the five organs was observed in 18, 15, 13, 8, 18, 5 subjects, respectively. 7 had h/o malignancies: 3 renal cell, 4 breast, 3 thyroid, 4 others. 3 cerebellar gangliocytomas and 2 others were measurable by CT or MRI. PTEN mutations: 6 families in Exon 1-2, 1 in Exon 4, 9 in Exon 5-8. All but one (D24H) were truncating mutations. 11 of 16 pts who completed a 56-day course reported subjective improvement in energy, mood, focus or skin lesion. Pts with Ex6-8 mutation (n=4) had a median SUV decrease of 29.4%. Regression of skin and GI lesions was observed by dermoscopy or endoscopy. Cerebellar evaluation showed a significant improvement in a total SARA score at 1 month (n=9, p=0.034). 3 pts were treated for only 28 days due to voluntary withdrawal. IHC analysis in skin and GI benign lesions showed a decrease in average P-S6K, P-S6, Total S6, P-S6/Total S6 in response to S. P-S6K/Total S6 ratios at d14 and d56 were significantly lower than at baseline (p=0.0026, 0.0391, respectively). The most common AEs (all grades >25%) were LFTs/Hb (39%), fatigue/hypercholesterolemia (28%). Grade 3 AEs: 1 pt hypophosphatemia/lymphopenia. Conclusions: A 56-day course of S was well tolerated in subjects with CS and was associated with improvement in symptoms, skin/GI lesions, cerebellar function and decreased mTOR signaling. Clinical trial information: NCT00971789.