Author of

• 10720

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  P1.09 - Poster Session 1 - Combined Modality (ID 212)

  • Event: WCLC 2013
  • Type: Poster Session
  • Track: Combined Modality
  • Presentations: 1
  • Moderators:
  • Coordinates: 10/28/2013, 09:30 - 16:30, Exhibit Hall, Ground Level

  • 10731

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    P1.09-011 - Phase I clinical trial assessing the MEK inhibitor selumetinib (AZD6244; ARRY-142886) with concomitant thoracic radiotherapy (RT) in patients with Stage III-IV non small cell lung cancer (NSCLC) (ID 1415)

    09:30 - 09:30  |  Author(s): K. Williams
    • Abstract

    Background
    The RAS/RAF/MEK/ERK signalling cascade has a central role in cancer proliferation and in modulating response to treatment. RAS mutations can confer a radiation-refractory phenotype and MAPK signaling can be stimulated by treatment with ionizing radiation in non-small cell lung cancer (NSCLC). Selumetinib (AZD6244; ARRY-142886) is an orally available inhibitor of MEK1/2 which was shown to enhance the effect of radiotherapy in preclinical studies. This effect was due to the ability of selumetinib to directly sensitize tumor cells to the cytotoxic effect of radiation and to modulate tumor vessel functionality by reducing VEGF-A expression. In a Phase II study, selumetinib given in combination with docetaxel showed promising activity in NSCLC patients with KRAS activating mutations. Aim To determine the recommended Phase II dose (RP2D) of selumetinib in combination with standard dose thoracic radiotherapy (RT) in NSCLC.

    Methods
    Selumetinib (Hyd-Sulfate capsule) was administered orally twice daily as a single agent for one week and then in combination with thoracic RT for 6 to 6.5 weeks (60 to 66 Gy in 30 to 33 fractions) in a single institution, open label Phase I trial using a modified Fibonacci sequence. Prior standard chemotherapy was permitted with a minimum interval between day8 of the last cycle of chemotherapy and day1 of administration of selumetinib of ≥ 2weeks. Other eligibility included: histologic or cytologic diagnosis of NSCLC, stage III not suitable for concurrent chemo-radiotherapy or stage IV with dominant thoracic symptoms, disease encompassable within a radical RT treatment volume, ECOG PS 0-1., no prior RT or investigational agents.

    Results
    A total of six consecutive patients with inoperable stage III (n=3) or stage IV (n=3) NSCLC were given selumetinib 50 mg twice daily (dose level 1) with concomitant thoracic RT (59.8-66 Gy in 30-33 fractions). All patients completed the combined treatment. Selumetinib delivery was > 80%. Four out of the six patients had dose interruptions of 2-3 days due to expected adverse events (AEs). Skin rash (6/6), diarrhoea (5/6) and fatigue (4/6) were the most common toxicities. Grade 3/4 AEs included hypertension (2/6), diarrhoea (2/6), skin rash (1/6), pulmonary embolism (1/6), fatigue (1/6) and pericardial effusion (1/6). Pulmonary embolism (grade 3) was considered not related to the study treatment. One patient experienced dose limiting toxicity (DLT) consisting of a combination of diarrhoea (grade 3) and fatigue (grade 3). Response to treatment was assessed 4 weeks post RT. Distant recurrence was seen in 1 patient; 3 patients had SD, 1 patient experienced a PR and 1 a CR. Median duration of response was 2 months (range 1-4 months).

    Conclusion
    Selumetinib given at 50 mg twice daily with concomitant radical thoracic RT was tolerated with no unexpected toxicities or enhancement of expected RT toxicities. Although the protocol-defined criteria to further escalate the selumetinib dose were met, because of the heterogeneous and small patient cohort and AEs encountered further evaluation of the 50 mg twice daily was preferred in order to obtained additional safety data. An expanded cohort of 15 patients having additional FLT-PET scans.