Bio

Clinical Focus


  • Cancer
  • Oncology

Academic Appointments


Professional Education


  • Board Certification: Oncology, American Board of Internal Medicine (2014)
  • Residency:Stanford University Hospital -Clinical Excellence Research Center (2011) CA
  • Fellowship:Stanford Hospitals and Clinics (2014) CA
  • Medical Education:Northeastern Ohio Medical University (2007) OH
  • Board Certification: Internal Medicine, American Board of Internal Medicine (2011)

Publications

All Publications


  • Pruritus as a Paraneoplastic Symptom of Thymoma JOURNAL OF THORACIC ONCOLOGY Padda, S. K., Shrager, J. B., Riess, J. W., Pagtama, J. Y., Tisch, A. J., Kwong, B. Y., Liang, Y., Schwartz, E. J., Loo, B. W., Neal, J. W., Hardy, R., Wakelee, H. A. 2015; 10 (11): E110-E112
  • Dovitinib and erlotinib in patients with metastatic non-small cell lung cancer: A drug-drug interaction LUNG CANCER Das, M., Padda, S. K., Frymoyer, A., Zhou, L., Riess, J. W., Neal, J. W., Wakelee, H. A. 2015; 89 (3): 280-286

    Abstract

    Erlotinib is a FDA approved small molecule inhibitor of epidermal growth factor receptor and dovitinib is a novel small molecule inhibitor of fibroblast growth factor and vascular endothelial growth factor receptor. This phase 1 trial was conducted to characterize the safety and determine the maximum tolerated dose of erlotinib plus dovitinib in patients with previously treated metastatic non-small cell lung cancer.Escalating dose cohorts of daily erlotinib and dovitinib dosed 5 days on/2 days off, starting after a 2-week lead-in of erlotinib alone, were planned. A potential pharmacokinetic interaction was hypothesized as dovitinib induces CYP1A1/1A2. Only cohort 1 (150mg erlotinib+300mg dovitinib) and cohort -1 (150mg erlotinib+200mg dovitinib) enrolled. Plasma concentrations of erlotinib were measured pre- and post-dovitinib exposure.Two of three patients in cohort 1 had a DLT (grade 3 transaminitis and grade 3 syncope). Two of 6 patients in cohort -1 had a DLT (grade 3 pulmonary embolism and grade 3 fatigue); thus, the study was terminated. Erlotinib exposure (average Cmax 2308±698ng/ml and AUC 0-24 41,030±15,577 ng×h/ml) approximated previous reports in the six patients with pharmacokinetic analysis. However, erlotinib Cmax and AUC0-24 decreased significantly by 93% (p=0.02) and 97% (p<0.01), respectively, during dovitinib co-administration.This small study demonstrated considerable toxicity and a significant pharmacokinetic interaction with a marked decrease in erlotinib exposure in the presence of dovitinib, likely mediated through CYP1A1/1A2 induction. Given the toxicity and the pharmacokinetic interaction, further investigation with this drug combination will not be pursued.

    View details for DOI 10.1016/j.lungcan.2015.06.011

    View details for Web of Science ID 000360513200010

    View details for PubMedID 26149476

  • Diffuse High Intensity PD-L1 Staining in Thymic Epithelial Tumors JOURNAL OF THORACIC ONCOLOGY Padda, S. K., Riess, J. W., Schwartz, E. J., Tian, L., Kohrt, H. E., Neal, J. W., West, R. B., Wakelee, H. A. 2015; 10 (3): 500-508

    Abstract

    Blockade of the immune checkpoint programmed death receptor ligand-1 (PD-L1)/PD-1 pathway has well-established clinical activity across many tumor types. PD-L1 protein expression by immunohistochemistry is emerging as a predictive biomarker of response to these therapies. Here, we examine PD-L1 expression in a thymic epithelial tumor (TET) tissue microarray (TMA).The TMA contained 69 TETs and 17 thymic controls, with each case represented by triplicate cores. The TMA was stained with rabbit monoclonal antibody (clone 15; Sino Biological, Beijing, China) to human PD-L1. PD-L1 staining was scored based on intensity as follows: 0 = none, 1 = equivocal/uninterpretable, 2 = weak, and 3 = intermediate-strong. Those cases with all cores scoring three in the epithelial component were categorized as PD-L1 and the remaining as PD-L1.PD-L1 scores were more frequent in TETs than in controls (68.1% versus 17.6%; p = 0.0036). PD-L1 scores and histology were significantly correlated, with higher intensity staining in World Health Organization (WHO). B2/B3/C TETs. Only 14.8% of TETs had PD-L1 staining of associated lymphocytes. In an adjusted analysis (age/sex), PD-L1 TETs had a significantly worse overall survival (hazard ratio: 5.40, 95% confidence interval: 1.13-25.89; p = 0.035) and a trend for worse event-free survival (hazard ratio: 2.94, 95% confidence interval: 0.94-9.24; p = 0.064).PD-L1 expression was present in all cases of TETs within the epithelial component but only in a minority in the lymphocytic component. TETs stained more intensely for PD-L1 than in controls, and PD-L1 TETs were associated with more aggressive histology and worse prognosis. This study lends rationale to a clinical trial with anti-PD-1/PD-L1 therapy in this rare tumor type.

    View details for DOI 10.1097/JTO.0000000000000429

    View details for Web of Science ID 000350118000019

  • Pemetrexed in patients with thymic malignancies previously treated with chemotherapy LUNG CANCER Liang, Y., Padda, S. K., Riess, J. W., West, R. B., Neal, J. W., Wakelee, H. A. 2015; 87 (1): 34-38

    Abstract

    Thymic malignancies are rare, with limited published trials of chemotherapy activity. We performed a retrospective analysis of pemetrexed activity in patients with thymic malignancies.Patients with unresectable histologically confirmed invasive, recurrent, or metastatic thymoma or thymic carcinoma seen at the Stanford Cancer Center between January 2005 and November 2013 were identified, and those who were treated with pemetrexed in the second-line setting and beyond were included in this analysis.A total of 81 thymic malignancy patients were identified, of whom 16 received pemetrexed alone (N=14) or in combination (N=2). There were 10 patients (62.5%) with thymic carcinoma and 6 patients (37.5%) with thymoma. Among the 6 patients with thymoma, best response was 1 (17%) with a partial response (PR) and 5 (83%) with stable disease (SD). At a median follow-up of 21.2 months, the median PFS in the thymoma patients was 13.8 months (95% CI, 4.9-22.6 months) and the median OS was 20.1 months (95% CI, 16.4-23.9 months). Among the 10 patients with thymic carcinoma, best response to treatment was 1 (10%) PR, 5 (50%) SD, and 4 (40%) progressive disease (PD). At a median follow-up of 13.5 months, the median PFS in patients with thymic carcinoma was 6.5 months (95% CI, 0.2-12.8 months) and the median OS was 12.7 months (95% CI, 2.9-22.5 months).This small retrospective study demonstrates modest pemetrexed activity and disease stabilization in thymic malignancies with a clinically meaningful duration, and supports previous reports of pemetrexed efficacy in these rare diseases.

    View details for DOI 10.1016/j.lungcan.2014.11.006

    View details for Web of Science ID 000348886100006

  • Early-Stage Non-Small Cell Lung Cancer: Surgery, Stereotactic Radiosurgery, and Individualized Adjuvant Therapy SEMINARS IN ONCOLOGY Padda, S. K., Burt, B. M., Trakul, N., Wakelee, H. A. 2014; 41 (1): 40-56

    Abstract

    Despite cures in early stage (IA-IIB) non-small cell lung cancer (NSCLC), the 5-year survival rate is only 36%-73%. Surgical resection via lobectomy is the treatment of choice in early-stage NSCLC, with the goal being complete anatomic resection of the tumor and mediastinal lymph node evaluation. Newer technologies, including the minimally invasive thoracoscopic approach and the many techniques available to stage the mediastinum, have introduced advantages over traditional approaches in achieving this goal. The advent of stereotactic ablative radiotherapy (SABR) has changed how we treat those patients who cannot undergo surgery secondary to comorbidities or patient preference. SABR allows for precise radiation delivery in a short course and at high doses. Adjuvant cisplatin-based chemotherapy is the standard of care for completely resected high-risk stage IB and stage II NSCLC based on a ~5% improvement in 5-year overall survival. The concept of customized adjuvant chemotherapy is emerging, and we will explore the potential value of targeting tumor mutations with available drugs (ie, epidermal growth factor receptor [EGFR] mutations with erlotinib), a strategy that for the moment should be restricted to clinical trials.

    View details for DOI 10.1053/j.seminoncol.2013.12.011

    View details for Web of Science ID 000332347100006

    View details for PubMedID 24565580

  • A Case Series of Lengthy Progression-Free Survival With Pemetrexed-Containing Therapy in Metastatic Non-Small-Cell Lung Cancer Patients Harboring ROS1 Gene Rearrangements CLINICAL LUNG CANCER Riess, J. W., Padda, S. K., Bangs, C. D., Das, M., Neal, J. W., Adrouny, A. R., Cherry, A., Wakelee, H. A. 2013; 14 (5): 592-595

    View details for DOI 10.1016/j.cllc.2013.04.008

    View details for Web of Science ID 000324342400018

    View details for PubMedID 23810364

  • Phase I and pharmacokinetic study of bexarotene in combination with gefitinib in the third-line treatment of non-small-cell lung cancer: brief report ANTI-CANCER DRUGS Padda, S. K., Chhatwani, L., Zhou, L., Jacobs, C. D., Lopez-Anaya, A., Wakelee, H. A. 2013; 24 (7): 731-735

    Abstract

    Gefitinib (an epidermal growth factor receptor tyrosine kinase inhibitor) and bexarotene (a rexinoid) affect similar oncogenic pathways and are both metabolized through cytochrome P450 CYP3A4. We studied the combination of bexarotene and gefitinib in the third-line treatment of advanced non-small-cell lung cancer to examine pharmacokinetic interactions and establish the maximum tolerated dose. This was a single-institution, nonrandomized, open-label, phase I clinical trial with a standard 3+3 dose escalation. Three patients were enrolled at each dose level on the basis of pharmacokinetic analysis with dose level 1 including gefitinib (Iressa) 250 mg oral daily and bexarotene (Targretin) 400 mg/m oral daily and dose level +1 including gefitinib 500 mg oral daily and bexarotene 400 mg/m oral daily. Patients received gefitinib alone for 2 weeks to allow for steady state and thereafter, bexarotene was added. In dose level 1, two of three patients had undetectable gefitinib levels at day 15 for unknown reasons. However, the peak levels on day 29 for all three patients receiving 250 mg of gefitinib with bexarotene are lower than published peak levels. Among the three patients in dose level +1, ∼40% lower gefitinib plasma concentrations were noted on day 29 compared with day 15 along with a mean 44% reduction in area under the plasma concentration-time curve from 0 to 24 h (AUC0-24). Bexarotene appears to lower the Cmax and AUC0-24 of gefitinib through cytochrome P450 CYP3A4. Our results have pharmacokinetic implications for ongoing trials that combine bexarotene with other small molecules in the era of personalized cancer therapy.

    View details for DOI 10.1097/CAD.0b013e32836100d7

    View details for Web of Science ID 000323222500009

    View details for PubMedID 23552470

  • MET inhibitors in combination with other therapies in non-small cell lung cancer. Translational lung cancer research Padda, S., Neal, J. W., Wakelee, H. A. 2012; 1 (4): 238-253

    Abstract

    MET and its ligand hepatocyte growth factor/scatter factor (HGF) influence cell motility and lead to tumor growth, invasion, and angiogenesis. Alterations in MET have been observed in non-small cell lung cancer (NSCLC) tumors, with increased expression associated with more aggressive cancer, as well as acquired resistance to epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKI). MET inhibitors act via two basic mechanisms. Small molecule inhibitors antagonize ATP in the intracellular tyrosine kinase domain of MET, with studies on the following agents reviewed here: tivantinib (ARQ-197), cabozantinib (XL-184), crizotinib (PF-02341066), amuvatinib (MP470), MGCD265, foretinib (EXEL-2880), MK2461, SGX523, PHA665752, JNJ-38877605, SU11274, and K252A. The monoclonal monovalent antibody fragment onartuzumab (MetMAb) is also discussed here, which binds to and prevents the extracellular activation of the receptor by ligand. MET inhibition may both overcome the negative prognostic effect of MET tumor expression as well as antagonize MET-dependent acquired resistance to EGFR inhibitors. Here we discuss MET inhibitors in combination with other therapies in lung cancer.

    View details for DOI 10.3978/j.issn.2218-6751.2012.10.08

    View details for PubMedID 25806189

  • A phase I dose-escalation and pharmacokinetic study of enzastaurin and erlotinib in patients with advanced solid tumors CANCER CHEMOTHERAPY AND PHARMACOLOGY Padda, S. K., Krupitskaya, Y., Chhatwani, L., Fisher, G. A., Colevas, A. D., Pedro-Salcedo, M. S., Decker, R., Latz, J. E., Wakelee, H. A. 2012; 69 (4): 1013-1020

    Abstract

    Enzastaurin, an oral serine/threonine kinase inhibitor, targets the protein kinase C and AKT pathways with anti-tumor and anti-angiogenic effects. Erlotinib, an oral epidermal growth factor receptor (EGFR) inhibitor, has activity in solid tumors. Based on the promising combination of EGFR inhibitors and anti-angiogenic agents, this phase I trial was initiated.This single-institution, open-label, non-randomized trial used a standard 3 + 3 dose-escalation model in patients with advanced solid malignancies including non-small-cell lung cancer (NSCLC). Two dose levels of enzastaurin (with loading doses) were explored: 250 mg daily and 500 mg daily. Erlotinib was given at 150 mg daily.Sixteen patients were enrolled in this study (median age, 64 years). Most patients were heavily pre-treated, female, and Caucasian and had NSCLC. The highest dose of enzastaurin, 500 mg daily, was tolerated with no unexpected adverse events and no alteration in the pharmacokinetics of either drug at this dose level. The mean clearance was 5.75 L/h for erlotinib and 53.8 L/h for enzastaurin. The most common possibly drug-related grade 3-4 adverse events included diarrhea (25.0%), neurologic symptoms (18.8%), and vomiting (18.8%). Activity was noted, with a partial response in one patient and prolonged disease stability for >12 cycles in three patients.The combination of enzastaurin 500 mg daily and erlotinib 150 mg daily is well tolerated and does not alter the pharmacokinetics of the individual drugs, with clinical activity seen. A phase II trial of this combination has been initiated in patients with advanced-stage NSCLC.

    View details for DOI 10.1007/s00280-011-1792-8

    View details for Web of Science ID 000302327300019

    View details for PubMedID 22160298

  • Maintenance Bevacizumab is Associated With Increased Hemoglobin in Patients With Advanced, Nonsquamous, Non-Small Cell Lung Cancer CANCER INVESTIGATION Riess, J. W., Logan, A. C., Krupitskaya, Y., Padda, S., Clement-Duchene, C., Ganjoo, K., Colevas, A. D., San Pedro-Salcedo, M., Kuo, C. J., Wakelee, H. A. 2012; 30 (3): 231-235

    Abstract

    We retrospectively analyzed hematologic parameters in 22 patients with advanced, nonsquamous, NSCLC undergoing VEGF inhibition on a phase II clinical trial of bevacizumab, carboplatin, and gemcitabine. We also examined TTP in relation to hemoglobin changes. Median hemoglobin increased significantly from a 12.9 g/dL pretreatment to 13.8 g/dL (p =.01) after the second cycle of maintenance bevacizumab until the first off cycle measurement. There was no difference in TTP in patients who achieved a rise in hemoglobin compared with patients who did not (median 238 days vs. 268 days, p =.38.) Maintenance bevacizumab is associated with increased hemoglobin in advanced, nonsquamous, NSCLC patients.

    View details for DOI 10.3109/07357907.2012.656862

    View details for Web of Science ID 000300657200005

    View details for PubMedID 22360362

  • A Phase II First-Line Study of Gemcitabine, Carboplatin, and Bevacizumab in Advanced Stage Nonsquamous Non-small Cell Lung Cancer JOURNAL OF THORACIC ONCOLOGY Clement-Duchene, C., Krupitskaya, Y., Ganjoo, K., Lavori, P., McMillan, A., Kumar, A., Zhao, G., Padda, S., Zhou, L., San Pedro-Salcedo, M., Colevas, A. D., Wakelee, H. A. 2010; 5 (11): 1821-1825

    Abstract

    Bevacizumab improves responses and progression-free survival when added to first-line paclitaxel/carboplatin or cisplatin/gemcitabine for patients with advanced nonsquamous non-small cell lung cancer. This study was designed to evaluate toxicities and efficacy of gemcitabine/carboplatin/bevacizumab.Patients with untreated advanced nonsquamous non-small cell lung cancer, with no evidence of brain metastases and not on anticoagulation were eligible. Patients received gemcitabine 1000 mg/m on days 1 and 8; carboplatin area under the curve 5 day 1; and bevacizumab 15 mg/kg day 1 every 3 weeks for up to six cycles. Bevacizumab was then continued every 3 weeks until disease progression or unacceptable toxicity.From July 2006 to December 2008, 48 patients were enrolled: 23 (48%) men, 25 (52%) women, and 19 (40%) never smokers. One patient never received therapy and is not included in the analysis. Median cycle number was 8 (1-42) with 37 patients (78.7%) completing ?4 cycles of three drugs. Dose reductions occurred in 34 (72.3%) patients. Grade 3/4 toxicities included neutropenia (47%/15%), thrombocytopenia (11%/15%), anemia (6%/0%), dyspnea (6%/2%), bacterial pneumonia (4%/0%), and hypertension (4%/2%). No neutropenic fevers occurred. One patient died of hemoptysis. Grade 3 bleeding occurred in three other patients. There were seven (14.9%) partial responses. Median time to first event (progression/death/toxicity requiring discontinuation) was 6.4 months (95% confidence interval: 4.8-7.9 months). The median overall survival (OS) was 12.8 months (95% confidence interval: 10.0-16.5). The OS is 57% at 1 year and 10% at 2 years.Although perhaps skewed by a high proportion of nonsmokers and women, treatment with gemcitabine/carboplatin/bevacizumab has an acceptable toxicity profile with promising median OS despite a low response rate.

    View details for DOI 10.1097/JTO.0b013e3181f1d23c

    View details for Web of Science ID 000283491100017

    View details for PubMedID 20881641

  • Complications of ablative therapies in lung cancer CLINICAL LUNG CANCER Padda, S., Kothary, N., Donington, J., Cannon, W., Loo, B. W., Kee, S., Wakelee, H. 2008; 9 (2): 122-126

    Abstract

    Two cases of complications secondary to the use of microwave ablation (MWA) in non-small-cell lung cancer (NSCLC) are discussed herein. The first case involves a 62-year-old man with stage IB NSCLC who declined surgery and pursued MWA. Within 7 months, he had residual disease at the MWA treatment site, and surgery was performed. The patient was found to have pleural and chest wall involvement, making complete resection impossible. The second case involves an 86-year-old woman with a second local recurrence of NSCLC and previous treatment including surgery and chemoradiation therapy. She was initially a surgical candidate but declined surgery and pursued MWA. Within 6 months, she had residual disease at the MWA treatment site. A second MWA was performed, and she developed a large cavitary abscess at the MWA site and had subsequent clinical decline. Less invasive ablation therapies and stereotactic radiosurgery are being developed for patients with inoperable lung cancer. Because these modalities have recently been developed, trials that clearly show efficacy and survival benefit are yet to be completed. Ablation procedures can result in complications, including residual disease and cavitary lesions susceptible to infection. These cases highlight the caution that should still be observed when recommending lung ablation strategies and the importance of selecting appropriate patients.

    View details for Web of Science ID 000255039000010

    View details for PubMedID 18501100