Andrew Wolanski

Phase I safety, pharmacokinetic and pharmacodynamic study of the poly (ADP-ribose) polymerase inhibitor veliparib with irinotecan in patients with advanced tumors

Purpose: PARP is essential for recognition and repair of DNA damage. In preclinical models, PARP inhibitors modulate topoisomerase I inhibitor–mediated DNA damage. This phase I study determined the MTD, dose-limiting toxicities (DLT), pharmacokinetics (PK), and pharmacodynamics (PD) of veliparib, an orally bioavailable PARP1/2 inhibitor, in combination with irinotecan. Experimental Design: Patients with advanced solid tumors were treated with 100 mg/m2 irinotecan on days 1 and 8 of a 21-day cycle. Twice-daily oral dosing of veliparib (10–50 mg) occurred on days 3 to 14 (cycle 1) and days −1 to 14 (subsequent cycles) followed by a 6-day rest. PK studies were conducted with both agents alone and in combination. Paired tumor biopsies were obtained after irinotecan alone and veliparib/irinotecan to evaluate PARP1/2 inhibition and explore DNA damage signals (nuclear γ-H2AX and pNBS1). Results: Thirty-five patients were treated. DLTs included fatigue, diarrhea, febrile neutropenia, and neutropenia. The MTD was 100 mg/m2 irinotecan (days 1 and 8) combined with veliparib 40 mg twice daily (days −1–14) on a 21-day cycle. Of 31 response-evaluable patients, there were six (19%) partial responses. Veliparib exhibited linear PK, and there were no apparent PK interactions between veliparib and irinotecan. At all dose levels, veliparib reduced tumor poly(ADP-ribose) (PAR) content in the presence of irinotecan. Several samples showed increases in γ-H2AX and pNBS1 after veliparib/irinotecan compared with irinotecan alone. Conclusions: Veliparib can be safely combined with irinotecan at doses that inhibit PARP catalytic activity. Preliminary antitumor activity justifies further evaluation of the combination. Clin Cancer Res; 22(13); 3227–37. ©2016 AACR.

Abstract LB-202: Responses to sequential sapacitabine and seliciclib in patients with BRCA-deficient solid tumors.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Background: Sapacitabine is an orally administered nucleoside analogue; the active metabolite, CNDAC (2′-C-cyano-2′-deoxy-1-β-D-arabino-pentofuranosylcytosine), generates single-strand DNA breaks that are converted to double-strand DNA breaks (DSBs) during subsequent replication, resulting in cell death if unrepaired. Repair of CNDAC-induced DSBs is dependent on the homologous recombination (HR) repair pathway. Depletion or inhibition of components of the HR pathway (including ATM, BRCA1/2, Rad 51, and XRCC3) greatly sensitizes tumor cell lines to CNDAC-induced cell death in vitro . Seliciclib is an orally bioavailable inhibitor of cyclin-dependent kinases (CDKs) 2, 7 and 9. CDK2 has been shown to participate in DNA repair and to be a therapeutic target in BRCA-deficient cancers. Seliciclib inhibits DSB repair, and also reduces BRCA1 and BRCA2 mRNA levels in cancer cell lines, sensitizing tumor cells to CNDAC. This phase I study evaluates sequential sapacitabine and seliciclib. Methods: Dose escalation was conducted in patients with incurable solid tumors and adequate organ function with sapacitabine bid x 7 consecutive days (d1-7), seliciclib bid x 3 consecutive days (d8-10) followed by 11 days of rest. At least 3 patients were evaluated per dose level. MTD was the highest dose level at which less than one-third of at least 6 patients experienced cycle 1 DLT. Skin biopsies were obtained to assess DNA damage following sapacitabine (d8 vs pre-treatment) and further augmentation of DNA damage after seliciclib (d11 vs d8). Results: 38 patients were treated. The MTD is sapacitabine 50 mg bid/seliciclib 1200 mg bid. DLTs were reversible transaminase elevations and neutropenia. The most frequent adverse events (all cycles, regardless of causality) included, fatigue, abdominal pain, diarrhea, constipation, decreased appetite, nausea, vomiting, anemia, neutropenia, pyrexia, AST elevation, alkaline phosphatase elevation, creatinine elevation, hyperglycemia, hypophosphatemia, cough, and alopecia, the majority mild to moderate in intensity. Skin biopsies showed a 2.3-fold increase in γ-H2AX staining post-sapacitabine (n=16; p=0.007) and a further 0.58-fold increase post-seliciclib (n=12; p=0.069). Four confirmed PRs occurred in patients with pancreatic, breast (2 pts) and ovarian cancer, all BRCA mutation carriers, lasting 21, 78+, 36+ and 42+ weeks, respectively. SD as best response ≥= 12 weeks was observed in 8 additional patients, including two BRCA mutation carriers with ovarian and breast cancer, lasting 64 and 21 weeks, respectively. Conclusions: Sequential sapacitabine and seliciclib is safe with preliminary antitumor activity. BRCA mutation carrier status may be a potential biomarker for response across multiple tumor types. An alternative schedule with concomitant administration of sapacitabine and seliciclib is currently under evaluation. Citation Format: Geoffrey I. Shapiro, John Hilton, James M. Cleary, Sara M. Tolaney, Leena Ghandi, Eunice L. Kwak, Jeffrey W. Clark, Andrew Wolanski, Tracy Bell, John Schulz, Sheelagh Frame, Chiara Saladino, Morag Hogben, Scott J. Rodig, Judy H. Chiao, David Blake. Responses to sequential sapacitabine and seliciclib in patients with BRCA-deficient solid tumors. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr LB-202. doi:10.1158/1538-7445.AM2013-LB-202

Abstract CT046: Phase I dose escalation study of the CDK4/6 inhibitor palbociclib in combination with the MEK inhibitor PD-0325901 in patients withRASmutant solid tumors

Background: Both MEK and CDK4/6 have been investigated as therapeutic targets in preclinical models of RAS mutant solid tumors. Multiple mechanisms contribute to synergism including the development of MAP kinase-dependence in RAS mutant cells exposed to CDK4/6 inhibition, leading to increased apoptosis, as well as enhanced induction of senescence with combinatorial vs. monotherapy treatment. We conducted a Phase 1 study of combined palbociclib and PD-0325901 in patients with RAS mutant solid tumors to assess safety, tolerability, and MTD, as well as pharmacokinetic parameters, preliminary efficacy and effects on mutant RAS allelic burden in plasma. Methods: Patients with RAS mutant solid tumors were enrolled utilizing a 3 + 3 design. Palbociclib and PD-0325901 were given orally once and twice daily, respectively for three of every four weeks. The maximum planned administered doses were 125 mg palbociclib daily and 8 mg PD-025901 twice daily. Pharmacokinetic parameters were measured on cycle 1 day 21 and plasma samples to measure RAS allelic burden were serially collected. Results: Twenty-five patients (17 with KRAS mutant NSCLC) who received at least one dose of each study drug were enrolled over 5 dose levels including (palbociclib/PD-0325901) 75/2, 75/4, 100/4, 125/4 and 125/8. The maximum administered dose of 125 mg palbociclib daily and 8 mg twice daily PD-0325901 was tolerable. One DLT of pneumonitis occurred at the 100/4 dose level. The most frequent (>10%) drug-related toxicities were leukopenia (72%), anemia (72%), thrombocytopenia (72%), neutropenia (64%), acneiform rash (64%), diarrhea (52%), fatigue (44%), lower extremity edema (32%), vomiting (28%), nausea (28%), oral mucositis (24%), increased AST (20%), increased creatinine (12%), epistaxis (12%), and blurred vision (12%). The median number of cycles completed was 3 (range: 1 - 28+). Across all patients, 1 patient (4%) with KRAS mutant NSCLC achieved partial response and 18 (72%) had stable disease as the best response. Eleven patients were progression-free > 3 months, and 6 were progression-free > 6 months, including 5 with KRAS mutant NSCLC, two of whom received prior immune checkpoint blockade. Among patients with KRAS mutant NSCLC, clinical benefit was seen among those with tumors harboring KRAS mutation alone, as well as those with tumors demonstrating concomitant loss of TP53 or CDKN2AB. A dose-dependent decrease in plasma RAS allelic burden was observed across dose levels. Conclusions: Administration of combined palbociclib and PD-0325901 was tolerable and produced promising progression-free survival among patients with KRAS mutant NSCLC. Additional dose levels utilizing continuous MEK inhibition are being evaluated. Citation Format: Geoffrey I. Shapiro, John Hilton, Leena Gandi, Nicole Chau, James Cleary, Andrew Wolanski, Adrienne Anderson, Brian Beardslee, Faith Hassinger, Ketki Bhushan, Elizabeth Downey, Joseph Gibson, Solida Pruitt-Thompson, Alona Muzikansky, Suzanne Barry, Nora Feeney, Cloud Paweletz, Geoffrey Oxnard, Jeffrey Supko, Pasi Janne, Kwok-Kin Wong, Bruce Johnson. Phase I dose escalation study of the CDK4/6 inhibitor palbociclib in combination with the MEK inhibitor PD-0325901 in patients with RAS mutant solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT046. doi:10.1158/1538-7445.AM2017-CT046

Abstract CT047: Phase 1 dose-escalation study of the CDK inhibitor dinaciclib in combination with the PARP inhibitor veliparib in patients with advanced solid tumors

Background: Although PARP inhibition is effective against HR repair-deficient cancers, efficacy is limited by HR proficiency, whether present de novo or as a result of acquired resistance, prompting HR disrupting strategies to sensitize tumor cells. Inhibition of CDK1 and CDK12 compromise HR by blocking BRCA1 phosphorylation, affecting recruitment to sites of DNA damage, and by reducing HR gene expression, respectively. Dinaciclib is a pan-CDK inhibitor that inhibits both CDK1 and CDK12 at nanomolar potency. We conducted a Phase 1 study combining dinaciclib and veliparib in patients with advanced solid tumors who are not germline BRCA carriers. Methods: A 3+3 design was utilized. Veliparib was administered twice daily continuously in 28-day cycles. Dinaciclib was administered intravenously on days 8 and 22. In part 1A, escalation followed a two-dimensional schema, utilizing doses of dinaciclib between 10 - 45 mg/m2 and veliparib between 20 - 120 mg. In part 1B, veliparib was escalated between 200 mg - 400 mg with dinaciclib maintained at 30 mg/m2. PK and PD assessments were performed at baseline, after veliparib, and after the combination. Preliminary Results: Sixty-three heavily pretreated patients were enrolled in part 1A (n = 39) and 1B (n = 24). Thirty-four patients had breast or gynecologic malignancies. The MTD was 400 mg twice-daily veliparib with dinaciclib at 30 mg/m2. DLTs included G4 neutropenia > 7 days (n =1), febrile neutropenia (n = 1), mucositis (n = 1) and fatigue (n = 1). Common drug-related toxicities were neutropenia (78%), nausea (75%), fatigue (67%), electrolyte abnormalities (59%), elevated liver function tests (57%), diarrhea (52%), lymphopenia (52%), anemia (43%), dehydration (37%), anorexia (30%), vomiting (29%), hypoalbuminemia (29%), dizziness (29%), headache (22%), mucositis (18%), elevated creatinine (16%), alopecia (16%), thrombocytopenia (14%), abdominal pain (13%), insomnia (13%), and dysgeusia (11%). The median number of cycles completed was 2 (r: 1 - 10). One patient with TNBC achieved complete resolution of axillary adenopathy lasting > 8 months. Twenty-four patients (38%) had stable disease as the best response, with 9 progression-free > 4 months (TNBC, gynecologic and thymic ca). Paired tumor biopsies from one patient demonstrated reduced Ki-67 and increased gamma-H2AX staining after combination treatment compared to after veliparib alone. Conclusions: Dinaciclib administered at doses known to produce PD effects is tolerable with full dose veliparib. Anti-tumor activity is limited in non-BRCA carriers, possibly related to intermittent administration of a CDK inhibitor with known short half-life. Additional patients are being enrolled utilizing dinaciclib in more dose-intense schedules. Citation Format: Geoffrey I. Shapiro, Khanh T. Do, Sara M. Tolaney, John F. Hilton, James M. Cleary, Andrew Wolanski, Brian Beardslee, Faith Hassinger, Ketki Bhushan, Dongpo Cai, Elizabeth Downey, Solida Pruitt-Thompson, Suzanne M. Barry, Bose Kochupurakkal, Joseph Geradts, Christine Unitt, Alan D. D9Andrea, Alona Muzikansky, Richard Piekarz, L. Austin Doyle, Jeffrey Supko. Phase 1 dose-escalation study of the CDK inhibitor dinaciclib in combination with the PARP inhibitor veliparib in patients with advanced solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr CT047. doi:10.1158/1538-7445.AM2017-CT047

Abstract 3157: Serial droplet digital PCR (ddPCR) of plasma cell-free DNA (cfDNA) as pharmacodynamic (PD) biomarker in Phase 1 clinical trials for patients (pts) with KRAS mutant non-small cell lung cancer (NSCLC)

Introduction: Phase 1 clinical trials of novel therapeutics have historically focused on toxicity, but increasingly are doubling as efficacy studies in biomarker-enriched populations. Given the small sample sizes (∼3-6 patients per dose), response on imaging may be a coarse marker of therapeutic effect. Here we piloted serial ddPCR of plasma cfDNA as a PD marker in a phase I combination study of a MEK inhibitor and a CDK 4/6 inhibitor in patients with RAS mutated cancers. Methods / Results: Twenty-five pts with RAS-mutated cancer (incl. 17 patients with KRAS-mutant NSCLC) have been enrolled to date in a phase I dose escalation trial of the MEK inhibitor PD-0325901 with the CDK4/6 inhibitor palbociclib (NCT02022982). Plasma for cfDNA genotyping was collected at baseline prior to therapy and at the beginning of cycle 2. Plasma genotyping for KRAS G12X mutations was performed using a validated and highly quantitative droplet digital PCR assay. Pts were enrolled in 5 dose level cohorts ranging from 75 mg palbociclib daily (3 weeks on, 1 week off) with 2 mg PD-0325901 BID (3 weeks on 1week off) to 125 mg palbociclib daily with 8 mg PD-0325901 BID (Table). KRAS mutations were detected in 14/24 pts at baseline (59%, median 1402 copies/mL plasma, range: 11-93000), consistent with the previously reported sensitivity of 64%. A second blood draw at cycle 2 was obtained for all 14 pts. A positive plasma response, defined as decrease of KRAS G12X mutants from first to second dose, was observed in 6 pts (range -6% - -100%) with the most plasma responders (n = 4 pts) at the maximum administered dose. At lower administered doses, there was a median increase in plasma KRAS mutant levels. Conclusions: Increasing dose levels resulted in more consistent decreases in KRAS mutation in cfDNA, consistent with a dose-dependent pharmacodynamic effect.These results highlight the potential value of serial plasma ddPCR as a PD marker in early phase clinical trials. Citation Format: Cloud P. Paweletz, Geoffrey R. Oxnard, Nora Feeney, John F. Hilton, Leena Gandhi, Khanh T. Do, Adrienne Anderson, Andrew Wolanski, Alexander Tejeda, Jessie M. English, Paul T. Kirschmeier, Pasi A. Janne, Geoffrey I. Shapiro. Serial droplet digital PCR (ddPCR) of plasma cell-free DNA (cfDNA) as pharmacodynamic (PD) biomarker in Phase 1 clinical trials for patients (pts) with KRAS mutant non-small cell lung cancer (NSCLC). [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3157.

Phase I safety, pharmacokinetic and pharmacodynamic study of the poly (ADP-ribose) polymerase inhibitor veliparib with irinotecan in patients with advanced solid tumors

Purpose: PARP is essential for recognition and repair of DNA damage. In preclinical models, PARP inhibitors modulate topoisomerase I inhibitor–mediated DNA damage. This phase I study determined the MTD, dose-limiting toxicities (DLT), pharmacokinetics (PK), and pharmacodynamics (PD) of veliparib, an orally bioavailable PARP1/2 inhibitor, in combination with irinotecan. Experimental Design: Patients with advanced solid tumors were treated with 100 mg/m2 irinotecan on days 1 and 8 of a 21-day cycle. Twice-daily oral dosing of veliparib (10–50 mg) occurred on days 3 to 14 (cycle 1) and days −1 to 14 (subsequent cycles) followed by a 6-day rest. PK studies were conducted with both agents alone and in combination. Paired tumor biopsies were obtained after irinotecan alone and veliparib/irinotecan to evaluate PARP1/2 inhibition and explore DNA damage signals (nuclear γ-H2AX and pNBS1). Results: Thirty-five patients were treated. DLTs included fatigue, diarrhea, febrile neutropenia, and neutropenia. The MTD was 100 mg/m2 irinotecan (days 1 and 8) combined with veliparib 40 mg twice daily (days −1–14) on a 21-day cycle. Of 31 response-evaluable patients, there were six (19%) partial responses. Veliparib exhibited linear PK, and there were no apparent PK interactions between veliparib and irinotecan. At all dose levels, veliparib reduced tumor poly(ADP-ribose) (PAR) content in the presence of irinotecan. Several samples showed increases in γ-H2AX and pNBS1 after veliparib/irinotecan compared with irinotecan alone. Conclusions: Veliparib can be safely combined with irinotecan at doses that inhibit PARP catalytic activity. Preliminary antitumor activity justifies further evaluation of the combination. Clin Cancer Res; 22(13); 3227–37. ©2016 AACR.